2025 AAFITN Abstract - 16th Biennial Congress of the Asian Australasian Federation of Interventional and Therapeutic Neuroradiology

A-007

Influence of Cerebral Microbleeds on Hemorrhagic Transformation after Successful Thrombectomy with Acute Ischemic Stroke from Large Artery Occlusion

Category: Acute Ischemic Stroke

Primary Author

Seung Young Chung

Daejeon Eulji Medical Center South Korea

Co-Author

Hyun Dong Yoo

Daejeon Eulji Medical Center

Jae Guk Kim

Daejeon Eulji Medical Center

Background and Purpose: This prospective cohort study aimed to investigate the relationship between the presence and burden of CMBs and the occurrence of hemorrhagic transformation (HT) following successful thrombectomy with acute ischemic stroke from LVO.

Materials and Methods: 132 patients with acute ischemic stroke with successful recanalization by thrombectomy for emergent LVO, were enrolled in this study. CMBs and HT assessed using T2-MRI with a validated scale. The primary outcome measure was the occurrence of HT following thrombectomy. We examined the association between the presence and burden of CMBs and HT. The secondary outcome was defined as a poor functional outcome, with mRS ranging from 3 to 6, assessed at 3 months after stroke onset.

Results: Among 132 patients (mean age 66.9±14.0 years, 68.9% male), 24 (18.2%) exhibited CMBs, and 59 (44.7%) developed HT. A total of 47 (49.2%) experienced a poor functional outcome, and the mortality rate was 11.3%. Statistical analysis revealed a significant association between the presence of CMBs and the occurrence of HT after successful thrombectomy (77.8% vs. 38.9%; P=0.002). Moreover, the presence of CMBs was significantly correlated with a higher likelihood of a poor functional outcome (77.8% vs. 42.9%; P=0.007) after adjustment of initial stroke severity and diffusion lesion volume. However, there was no observed association between the presence of CMBs and mortality (16.7% vs. 8.25%; P=0.426).

Conclusion: The presence of CMBs is significantly associated with the occurrence of HT and a poor functional outcome following successful thrombectomy. However, it does not appear to impact mortality rates in these patients.

A-023

Angioarchitectural Features of Cerebral Arteriovenous Malformations and Their Relationship with Epileptic Seizures: A Cross-Sectional Study in a Tertiary Hospital in Surabaya, Indonesia

Category: Cerebral Arteriovenous Malformation

Primary Author

Jovian Philip Swatan

Department of Neurology, Faculty of Medicine, Universitas Airlangga, Indonesia

Co-Author

Wardah Rahmatul Islamiyah

Department of Neurology, Faculty of Medicine, Universitas Airlangga

Achmad Firdaus Sani

Department of Neurology, Faculty of Medicine, Universitas Airlangga

Dedy Kurniawan

Department of Neurology, Faculty of Medicine, Universitas Airlangga

Shakir Husain

Director of Stroke and Neurointervention Foundation (SNIF), New Delhi, India

Background and Purpose: Epileptic seizures are the second most common clinical manifestation of cerebral arteriovenous malformations (AVMs). These seizures can significantly affect a patient’s quality of life and lead to increased healthcare costs for both individuals and the healthcare system. Previous studies have identified associations between certain angioarchitectural characteristics of AVMs and the occurrence of epileptic seizures. However, findings remain inconsistent across studies, and data from the Indonesian population are still limited. This study aims to identify the angioarchitectural features of cerebral AVMs associated with epileptic seizures in the Indonesian population, with the goal of improving diagnostic and management strategies to enhance patient outcomes.

Materials and Methods: This retrospective cross-sectional study included all patients diagnosed with cerebral AVM between January 2016 and December 2023. Eligible patients underwent three-dimensional cerebral angiography and had no other intracranial vascular abnormalities. Bivariate and multivariate analyses were performed to assess the relationship between demographic data, angioarchitectural features of cerebral AVMs, and the occurrence of epileptic seizures.

Results: A total of 92 patients (53 males, 39 females) met the inclusion criteria. Epileptic seizures were the second most common clinical manifestation, occurring in 40 patients (43.48%). Bivariate analysis identified significant associations between epileptic seizures and male gender (p = 0.037), AVM size ≥30 mm (p = 0.036), AVM components located in the cortical area (p = 0.011), absence of AVM hemorrhage (p < 0.001), feeding arteries from the cortical-pial region (p = 0.001), and exclusive superficial venous drainage (p = 0.021). Multivariate analysis further confirmed significant associations between epileptic seizures and age <35 years (p = 0.029), absence of AVM hemorrhage (p = 0.002), and feeding arteries from the cortical-pial region (p = 0.011).

Conclusion: This study highlights the relationship between AVM size, vascular component location, presence of AVM hemorrhage, and venous drainage patterns with the occurrence of epileptic seizures. Understanding these associations may inform more effective management strategies for patients with cerebral AVMs.

A-026

Vertebro-Vertebral Arteriovenous Fistulae: A Case Series of Endovascular Management at a Single Center

Category: Other Neurovascular and Rare Diseases

Primary Author

Pattarawit Withayasuk

Siriraj hospital Thailand

Co-Author

Ritthikrai Wichianrat

Siriraj center of interventional radiology

Boonrerk Sangpetngam

Siriraj hospital, Mahidol university

Ekawut Chankaew

Siriraj hospital, Mahidol university

Anchalee Churojana

Siriraj hospital, Mahidol university

Background and Purpose: Vertebro-vertebral arteriovenous fistulae (VVFs) are a rare disorder characterized by a direct shunt between the extracranial vertebral artery and the veins of the vertebral venous plexus. This study aims to com- prehensively review the characteristics and outcomes of endovascular treatments for VVFs at our center.

Materials and Methods: A retrospective review was conducted on 14 patients diagnosed with a VVF who underwent endovascular treatment at Siriraj Hospital from January 2000 to January 2023. The study assessed patient demo- graphics, presentation, fistula location, treatment strategies, endovascular techniques employed, and treatment outcomes.

Results: Among the 14 pa- tients, 11 (78.6%) were female, with an age range from 25 to 79 years (median: 50 years). Spontaneous VVFs were observed in 64.3% of the cases, including three associated with neurofibromatosis type 1 (NF-1). Iatrogenic injury accounted for two cases, and three patients had VVFs resulting from traffic accidents. A pulsatile neck mass and tinnitus, with or without neurological deficits, were common presenting symptoms. Active bleeding was observed in three cases with vascular injury, while uni- lateral proptosis, congestive heart failure, and incidental findings each presented in one patient. All the VVFs were successfully obliterated without major treatment complications. Parent vessel sacrifice was performed in 85.7% of the cases, while vertebral artery preservation was achieved in the remaining two patients. Embolic materials included detachable balloons, detachable coils, and n-butyl cyanoacrylate (NBCA) glue. All the presenting symptoms showed improvement, and no morbidity or mortality was observed.

Conclusion: Endovascular embolization is a feasible and effective approach for achieving complete VVF obliteration with safety. Parent artery sacrifice should not be reluctantly performed, particularly when adequate collateral circulation is demonstrated.

A-027

Comparative Evaluation of Imaging Modalities for Eligibility in Endovascular Treatment of Delayed Onset Acute Anterior Circulation Ischemic Stroke in Siriraj Hospital: A Retrospective Analysis

Category: Acute Ischemic Stroke

Primary Author

Pattarawit Withayasuk

Siriraj Center of Interventional Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Thailand

Co-Author

Rungsima Chudapongse

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand

Boonrerk Sangpetngam

Siriraj Center of Interventional Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand

Ekawut Chankaew

(Siriraj Center of Interventional Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand

Thaweesak Aurboonyawat

Siriraj Center of Interventional Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand

Anchalee Churojana

(Siriraj Center of Interventional Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand

Background and Purpose: The goal of this study is to evaluate the consistency between computed tomographic perfusion (CTP) according to the endovascular therapy following imaging evaluation for ischemic stroke (DEFUSE-3) criteria and other standard computed tomography (CT) imaging modalities, such as multi-phase CT angiography (MCTA) and unenhanced computed tomography (UECT), in assessing patient eligibility for EVT as determined by neurointerventionists evaluations.

Materials and Methods: This retrospective analysis included 64 patients with anterior circulation stroke and onset between 6 to 12 hours or unknown onset. Two neuro-interventionalists independently reviewed images and assessed eligibility for EVT based on the Alberta stroke program early CT score (ASPECTS) derived from UECT and collateral score obtained from MCTA. The results were then compared to CTP, utilizing the DEFUSE-3 criteria.

Results: Out of the 64 cases analyzed (mean age: 69 years ± 13.9 [SD]), 61 met DEFUSE-3 criteria for EVT by CTP, while 54 were deemed eligible based on an ASPECTS ≥ 6 and collateral score ≥ 3. Agreement between the modalities was moderate (Kappa coefficient score 0.4). When patients with ASPECTS score < 6 were excluded, concordance improved to perfect (Kappa coefficient score 1.0). Hence, concordance was significantly associated with ASPECTS scores ≥ 6 (P < 0.001).

Conclusion: In patients experiencing anterior circulation stroke with onset between 6 to 12 hours or unknown onset, excluding an ASPECTS score of 6 or higher, MCTA and UECT proved to be reliable for assessing endovascular treatment eligibility. These modalities may serve as substitutes for CTP and offer support in the clinical decision- making process.

A-030

A Study of a Previously Unrecognized C1 intraosseous vein: Analysis Using CT-Digital Subtraction Venography

Category: Other Head and Neck Pathologies

Primary Author

Takahiro Iinuma

Department of Neurosurgery, Keio University, School of Medicine, Japan

Co-Author

Tsubasa Miyauchi

Department of Neurosurgery, Keio University, School of Medicine

Katsuhiro Mizutani

Department of Neurosurgery, Keio University, School of Medicine

Takenori Akiyama

Department of Neurosurgery, Keio University, School of Medicine

Masahiro Toda

Department of Neurosurgery, Keio University, School of Medicine

Background and Purpose: A comprehensive understanding of the perivertebral venous anatomy is essential for elucidating the pathophysiological mechanisms underlying various clinical conditions, including arteriovenous shunts (AVSs) in the surrounding region. The present study aimed to delineate the complex venous architecture surrounding the vertebrae, with particular focus on characterizing previously unrecognized venous structures associated with the C1 vertebral bone.

Materials and Methods: Head computed tomography digital subtraction venography (CT-DSV) images from 289 patients (162 men and 167 women; aged 1 month to 93 years, average 56.1years), acquired preoperatively at our department, were retrospectively analyzed. The venous structures adjacent to the C1 vertebral bone and their connections were scrutinized by two investigators.

Results: Fifteen intraosseous veins were identified within the lateral mass of the C1 vertebra in 13 cases (4.5%; 3 men and 10 women; average 54.2 years). These venous structures were found on the right side in six cases and on the left side in seven. Most of these intraosseous channels connected the suboccipital cavernous sinus (SOCS) with the intervertebral veins (IVVs). Minor variations included channels connecting the vertebral vein (VV) with the SOCS, the VV with the IVVs, the VV with the anterior internal vertebral vein (AIVV), the VV with the posterior external venous plexus (PEVP), the AIVV with the PEVP, and the AIVV with the IVVs.

Conclusion: CT digital subtraction venography (CT-DSV) revealed venous structures coursing within the C1 vertebral lateral mass. These venous structures have not been described in the previous literature and may potentially be involved in diseases affecting the venous channels, including AVSs in this region. (300 words)

A-044

Sinus Preservation or Sacrifice? A Comparative Study of Single-Session Outcomes in Endovascular Treatment of Aggressive Intracranial Dural AVFs

Category: Dural Arteriovenous Fistulae

Primary Author

Chayada Harnroongroj

Siriraj Hospital, Mahidol University Thailand

Co-Author

Yanisa Ingkapassakorn

Siriraj Hospital, Mahidol University

Thanawat Sitthibunchakorn

Siriraj Hospital, Mahidol University

Pattarawit Withayasuk

Siriraj Hospital, Mahidol University

Boonrerk Sangpetngam

Siriraj Hospital, Mahidol University

Thaweesak Aurboonyawat

Siriraj Hospital, Mahidol University

Background and Purpose: Intracranial dural arteriovenous fistulas (dAVFs) are complex vascular lesions that challenge treatment strategies. While endovascular therapy is the gold standard, debate persists between sinus preservation and sacrifice approaches, particularly for low to intermediate dAVFs with non-critical sinus involvement.

This study compares the effectiveness, success rates, and complications of these two techniques in treating aggressive intracranial dAVFs after a single treatment session.

Materials and Methods: A retrospective analysis was conducted on 92 patients with 125 aggressive dAVFs (Cognard type IIA, IIB, and IIA+B) treated endovascularly between January 2018 and December 2023. Patients were divided into sinus preservation (n=25) and sinus sacrifice (n=100) groups. Cavernous-carotid fistulas, Cognard type II with critical sinus, and Cognard III-IV were excluded. Immediate post-operative and 3-6 month follow-up angiographic outcomes were evaluated, categorizing results as complete obliteration, benign, or aggressive. Complications and retreatment rates were also assessed.

Results: Sinus sacrifice achieved significantly higher complete obliteration rates compared to sinus preservation, both immediately post-operation (62% vs. 28%, p=0.003) and at 3-6 month follow-up (75% vs. 40%, p=0.002). The sinus preservation group had a higher retreatment rate (40% vs. 13%, p=0.003). No significant differences were found in procedural parameters between groups. Complication rates were lower in the sinus sacrifice group (8%) compared to the sinus preservation group (16%), though not statistically significant (p=0.234). Most complications were minor, with one case of major complication (pulmonary embolism) in the sinus sacrifice group.

Conclusion: This study demonstrates the superiority of sinus sacrifice over preservation in treating aggressive intracranial dAVFs. Sinus sacrifice achieved higher obliteration rates and lower retreatment needs, emphasizing the importance of normalizing pressure gradients over preserving specific venous routes. These findings suggest that sinus sacrifice should be considered a primary treatment option for most aggressive dAVFs with non-critical sinus involvement.

A-045

A Retrospective Analysis of Mechanical Thrombectomy for Primary Medium Vessel Occlusion at a Single Institution

Category: Acute Ischemic Stroke

Primary Author

Michihisa Narikiyo

Kawasaki Saiwai Hospital Japan

Co-Author

Yuichi Murayama

The Jikei University School of Medicine

Takashi Kawagoe

Kawasaki Saiwai Hospital

Hirokazu Nagasaki

Kawasaki Saiwai Hospital

Yoshifumi Tuboi

Kawasaki Saiwai Hospital

Background and Purpose: Mechanical thrombectomy (MT) for distal medium vessel occlusion (DMVO), including primary medium vessel occlusion (MeVO), has recently been evaluated through multiple studies. However, its clinical efficacy and safety profile remain under debate. This study aimed to retrospectively assess the outcomes of MT for primary MeVO at our institution and to characterize factors associated with favorable prognosis.

Materials and Methods: A total of 132 patients who underwent MT for MeVO between April 2016 and March 2024 were screened. Of these, 58 patients who met the inclusion criteria pre-stroke modified Rankin Scale (mRS) score of 0–2, initial evaluation by a neurosurgeon, and exclusion of in-hospital onset—were analyzed. Patients were stratified into two groups: those with favorable outcomes (discharge mRS 0–3, n=33) and those with poor outcomes (discharge mRS 4–6, n=25). Patient demographics, occlusion characteristics, procedural variables, and clinical outcomes were compared retrospectively. Statistical analyses were conducted using JMP®14.2.0 software.

Results: The favorable outcome group exhibited significantly lower baseline National Institutes of Health Stroke Scale (NIHSS) scores, fewer thrombectomy passes, and a markedly lower incidence of symptomatic intracranial hemorrhage (p<0.01). No statistically significant differences were observed between the groups regarding occlusion sites or specific thrombectomy techniques, including aspiration, combined methods, or stent retriever use. Notably, tortuous vascular anatomy was more frequently observed in the poor outcome group, potentially complicating procedural success.

Conclusion: Our findings suggest that lower baseline neurological severity, fewer retrieval attempts, and the absence of vascular tortuosity are positively associated with favorable clinical outcomes following MT for primary MeVO. Given the emerging but inconclusive evidence from recent randomized controlled trials, careful patient selection and individualized procedural strategies remain critical to optimizing outcomes. Future prospective studies are warranted to better define the role of MT in this patient population.

A-052

Endovascular treatment for carotid blowout syndrome: single centre experience

Category: Other Head and Neck Pathologies

Primary Author

Tze Phei Kee

National Neuroscience Institute Singapore

Co-Author

Hong Wan Yap

National Neuroscience Institute, Singapore

Wickly Lee

National Neuroscience Institute, Singapore

Joanna Pearly

National Neuroscience Institute, Singapore

Background and Purpose: Carotid blowout syndrome (CBS) is a challenging complication that arises in patients treated with head and neck cancer as a result of arterial wall necrosis from irradiation or direct tumor invasion. This retrospective review aims to identify factors affecting endovascular treatment decision of CBS between reconstructive and deconstructive techniques.

Materials and Methods: We conducted a retrospective review of all CBS cases with either internal carotid artery (ICA) or common carotid artery (CCA) as culprit vessel, treated endovascularly at our institution from January 2015 to June 2024. A total of 8 cases were identified. CBS was classified as type 1 (impending rupture), type 2 (sentinel bleeding) and type 3 (active massive bleeding).

Results: Out of the 8 cases, 4 underwent parent artery reconstruction with covered stent while the other 4 underwent parent artery sacrifice. Of the 4 patients treated with covered stent, 2 had type 3 CBS and 2 had type 1 CBS. Balloon test occlusion (BTO) was not performed. 3 out of 4 patients in this group had delayed complications: 1 patient had multiple rebleeding episodes with mild in-stent stenosis; 2 developed delayed stent occlusion with ipsilateral MCA infarct. Of the 4 patients treated with parent artery sacrifice, all presented with type 1 CBS. One patient failed BTO and had external carotid artery (ECA)-ICA bypass prior to occlusion of the offending ICA. The other 3 demonstrated good cross flow from contralateral ICA injection. 3 out of 4 patients in this group had complications: 2 developed infarcts of the occluded ICA territory and the other 1 patient had further bleeding episodes from the ipsilateral CCA (post ICA occlusion).

Conclusion: Endovascular treatment for CBS carries high complication rates with the current treatment strategies. For patients who passed BTO, parent artery sacrifice may be a more favorable option, as it is a more definitive treatment and does not require dual antiplatelet therapy. For patients who failed BTO, covered stent placement would be more favorable. Careful consideration of treatment strategy is essential to balance the risks of future ischaemic or haemorrhagic events.

A-053

Factors associated with Rupture of Flow-Related Aneurysms in Arteriovenous Malformations

Category: Cerebral Arteriovenous Malformation

Primary Author

Jirat Greetawee

Siriraj Hospital, Mahidol University Thailand

Co-Author

Pattarawit Withayasuk

Siriraj Hospital, Mahidol University

Boonrerk Sangpetngam

Siriraj Hospital, Mahidol University

Thaweesak Aurboonyawat

Siriraj Hospital, Mahidol University

Anchalee Churojana

Siriraj Hospital, Mahidol University

Ekawut Chankaew

Siriraj Hospital, Mahidol University

Background and Purpose: Flow-related aneurysms (FRAs) are common in patients with brain arteriovenous malformations (AVMs) and confer an elevated risk of intracranial hemorrhage. However, predictors of FRA rupture remain poorly defined. This study aimed to identify clinical and angiographic factors associated with rupture of FRAs.

Materials and Methods: We performed a retrospective cross-sectional study of AVM patients with a single flow-related aneurysm confirmed by digital subtraction angiography (DSA) between 2009 and 2023. Patient demographics, AVM characteristics, and aneurysm features were collected. Univariate and multivariate logistic regression analyses were conducted to determine predictors of aneurysm rupture, reported as odds ratios (OR) with 95% confidence intervals (CI).

Results: Eighty-nine patients were included (median age 45 years; 50% male). Twenty-two patients (24.7%) presented with ruptured FRAs. Ruptured aneurysms had significantly larger diameters compared to unruptured ones (5.85 mm vs. 2.4 mm, p<0.05). Univariate analysis identified several risk factors for rupture: aneurysm size, posterior circulation location, venous outlet stenosis, and saccular morphology with lobulation (p<0.05 for each). An aneurysm diameter ≥4 mm was a strong predictor of rupture (OR 17.31, 95% CI 5.24–56.80). In multivariate analysis, only aneurysm size ≥4 mm remained independently associated with rupture (adjusted OR 34.53, 95% CI 3.61–329.45, p<0.05). Endovascular treatment, particularly coil embolization, was the primary modality for ruptured aneurysms, whereas unruptured aneurysms were often managed

Conclusion: Aneurysm size ≥4 mm is the most significant independent predictor of rupture in flow-related aneurysms associated with AVMs. Although posterior circulation, venous stenosis, and lobulated morphology were associated with rupture in univariate analysis, their predictive power was not independent of size. These findings highlight the importance of aneurysm size in clinical decision-making and support early intervention for FRAs measuring 4 mm or larger to mitigate hemorrhagic risk.

A-054

Outcome analysis and concept development to identify the most appropriate Woven EndoBridge (WEB) size based on the different shapes of cerebral aneurysms

Category: Cerebral Aneurysm

Primary Author

Dae Chul Suh

GangNam St. Peter's Hospital South Korea

Co-Author

-

Background and Purpose: To analyze outcomes and identify the most effective method for selecting the optimal WEB size by correlating volumetric parameters with specific aneurysm configurations. The goal of this study is to improve the final outcomes of aneurysm treatment and reduce the WEB exchange rate, thereby minimizing the risk of selecting undersized or oversized WEBs.

Materials and Methods: Sixty consecutive aneurysms treated with the WEB device were included in this study. The volume measurements of the aneurysms, based on spherical and columnar configurations, were compared with the WEB volume to assess the accuracy of the device’s fit within the aneurysm. After categorizing the aneurysms into symmetric and asymmetric shapes, the asymmetric aneurysms were further classified into five types based on their configurations. We calculated the WEB index (WEB volume/aneurysm volume) to predict whether the aneurysms were undersized or oversized. Different aneurysm shape types were compared by using appropriate statistical analyses.

Results: Symmetric (65%) were more prevalent than asymmetric aneurysms (35%). Among the five types of aneurysm shapes, the column shape was the most common (n=32, 53%), followed by submarine (n=9), spherical (n=7), boots (n=6), and mitten (n=6) shapes. The WEB index was associated with the presence of stent-assisted procedures (oversizing) and the occurrence of sac remnants and/or recurrences (undersizing). There was one non-procedure-related death and two retreatments (3%) among the eight cases of residual and/or recurrent neck or sac during a mean follow-up period of six months (ranging from 3 to 17 months) via MRA, along with a mean clinical follow-up of eleven months (ranging from 3 to 28 months).

Conclusion: One of the essential steps in WEB embolization is th e measurement of aneurysm volume, which depends on its size (mean width and height) and shape types. Volume-based WEB selection (WEB index) is the most critical factor in determining the appropriate WEB size based on the aneurysm’s shape.

A-058

Intra Arterial Chemotherapy in Retinoblastoma

Category: Others

Primary Author

Umair Rashid Chaudhry

Department of Neuroradiology, Lahore General Hospital, Lahore Pakistan

Co-Author

-

Background and Purpose: To study the treatment outcomes of ophthalmic artery chemosurgery (OAC) in children with unregressed retinoblastoma after 6 cycles of systemic chemotherapy. STUDY DESIGN Interventional prospective case series. PLACE AND DURATION Lahore General Hospital over one year from October, 2017 to December, 2024. 500 Patients were recruited from the outpatient Department of Ophthalmology and treated at Neuroangio Suite, Lahore General Hospital, Lahore.

Materials and Methods: Children presenting with group D retinoblastoma and haring residual unregressed tumor completion of 6 cycles of chemotherapy were included in the study. The tumor was classified according to the international classification of Retinoblastoma System (ICRB) on EUA treatment outcome of (OC) was evaluated in terms of signs of regression. The ophthalmic artery was cannulised through digital substraction angiography (DSA).

Results: Our study included 500 children, 300 children had unilateral retinoblastoma while 200 children were one eyed due to enucleation of the other eye with group E tumor. Signs of regression appeared after single OAC in 300 children, and after 2 OAC sessions in 100 children. Cannulisation of ophthalmic artery failed in 100 children who had narrow intra-arterial caliber. A total of upto 11 treatment sessions were done, 200 with successful cannulisation of ophthalmic artery infundibulum. Melphalan was used alone in 5 sessions and melphalan + topotecan was given in the 4 sessions. Severe vomiting within 24 hours post treatment was observed after 8 treatment sessions, mild to moderate reversible orbital swelling was observed after 7 treatment sessions. 15 children had severe prolonged orbital swelling which resolved 8 weeks after treatment with vision preservation. Five children had chorio toxicity 12 hours post treatment and permanent loss of vision. All patients were followed for mean 10 + SD 1.2 months.

Conclusion: Ophthalmic artery chemosurgery is a useful tool for addressing residual intraocular retinoblastoma after completion of systemic chemotherapy in eyes with group D retinoblastoma at the time of initial presentation.

A-060

Central venous stenosis Mimicking intracranial venous Hypertension from dural Arteriovenous fistula (DAVF)/ Carotidocavernous fistula (CCF) : a diagnostic and Therapeutic dilemma in a Hemodialysis patient

Category: Dural Arteriovenous Fistulae

Primary Author

Si Zhao Tang

National University Hospital, National University Health System Singapore

Co-Author

Gopinathan Anil

National University Hospital, National University Health System

Background and Purpose: Intracranial venous hypertension secondary to central venous stenosis is a rare but important mimicker of carotidocavernous fistula (CCF) and dural arteriovenous fistula (dAVF), particularly in patients on long-term hemodialysis access. We present a case of symptomatic intracranial venous reflux initially suspected to be CCF/dAVF, which was ultimately found to be due to isolated left brachiocephalic vein (BCV) stenosis.

Materials and Methods: A 56-year-old woman with end-stage kidney disease on hemodialysis via tunnelled right internal jugular vein (IJV) pheresible catheter and known left upper limb brachiocephalic (BC) arteriovenous fistula (AVF). She presented with left eye proptosis, chemosis, and raised intraocular pressure. Initial workups including CT brain venogram suggested intracranial venous congestion and raised suspicion for dAVF.

Results: Diagnostic intra- and extra-cranial angiography did not identify any CCF/dAVF. Left upper limb BC AVF fistulography and central venogram were then performed instead, which revealed tight focal stenosis at the left BCV with extensive venous collaterals and venous reflux. Balloon venoplasty (14×40 mm Atlas) was attempted but showed significant recoil. Hence, the decision was made to stent the left BCV instead with a self-expanding nitinol stent (Abre 16×80 mm), which was successful and resulted in immediate resolution of venous hypertension and reflux on angiography. The patient’s ocular symptoms resolved post-procedure with normalisation of intraocular pressure (from 25 mmHg to 9 mmHg in the left eye). There were no procedural complications.

Conclusion: This case illustrates the importance of considering central venous stenosis as a reversible cause of intracranial venous congestion in patients on long-term hemodialysis, even when contralateral central venous pathways are patent. Central venous stenosis may occasionally mimic CCF and/or dAVF, both clinically and radiologically. Venous stenting can be an effective therapeutic option, although caution is warranted when extrinsic compression is suspected. Awareness of this entity can prevent unnecessary neurosurgical or neurointerventional procedures and guide appropriate vascular intervention.

A-064

Technical tips and clinical aspects of WEB insertion for wide neck bifurcation aneurysm.

Category: Cerebral Aneurysm

Primary Author

Shingo Matsuda

Hiroshima University Hospital Japan

Co-Author

Daizo Ishii

Masashi Kuwabara

Takeshi Hara

Nobutaka Horie

Background and Purpose: Treatment for wide neck bifurcation intracranial aneurysms using endovascular therapy is still challenging in spite of the development of treatment devices. Flow disruption with the Woven EndoBridge (WEB) is an innovative treatment device for wide-neck bifurcation intracranial aneurysms. To achieve successful treatment, it is important to select the appropriate size of WEB and deploy the precise location. We report clinical tips and intraoperative findings based on our experience treated with WEB.

Materials and Methods: Five patients (5 aneurysms: case1-case5) consecutively treated with WEB in our institution for a bifurcation aneurysm since June 2024 were retrospectively evaluated. Intraoperative findings of each case were noted. All aneurysm measurements were performed using Digital Subtraction Angiography (DSA) results, and aneurysm volume calculated with 3D DSA reconstruction imaging using software.

Results: Calculated aneurysm volume was ranged 93.8 - 659.1ml and mean devise-aneurysm volume ratio was 0.84±0.14. The mean aspect ratio and dome-to-neck ratio were 1.41±0.53 and 1.66±0.53. In two of the five cases, WEB size was changed as intraoperative findings. These two cases were higher values of aspect ratio and dome-to-neck ratio than in other three cases. In four of the five cases, diameter of the WEB was chosen 1mm larger than average aneurysm width on orthogonal projections. In one of the five cases, height of the WEB was chosen 1mm less than the aneurysm minimal height. One of the intra operative findings was it was important to consider that vessel deviation due to insertion of microcatheter into target vessel, and catheter manipulation could be more difficult than preoperative expectation. In case4, an attempt was made to place a WEB in the anterior communicating artery aneurysm, but as part of the WEB protruded into the parent vessel, a stent (Neuroform Atlas) was placed from A2 to A1, jacking up the WEB and securing the parent vessel, resulting in successful embolization.

Conclusion: In irregular aneurysms with high aspect ratio and dome-to-neck ratio, selecting appropriate WEB size is more challenging. The rescue use of intracranial stent with WEB is reasonable, and vessel deviation, approach side, and devise system are well considered.

A-070

Anatomical Fixation of the Internal Carotid Artery by the Stylopharyngeus Muscle Leading to Kinking After Carotid Artery Stenting

Category: Other Head and Neck Pathologies

Primary Author

Keita Fujii

Department of Neurosurgery, Yokohama City University Gradu- ate School of Medicine, Yokohama, Kanagawa, Japan, Japan

Co-Author

Kentaro Mori

Department of Neurosurgery, Yokohama Sakae Kyosai Hospital, Yokohama, Kanagawa, Japan

Motohiro Nomura

Department of Neurosurgery, Yokohama Sakae Kyosai Hospital, Yokohama, Kanagawa, Japan

Yasunobu Nakai

Department of Neurosurgery, Yokohama Sakae Kyosai Hospital, Yokohama, Kanagawa, Japan

Kengo Funakoshi

Department of Neurosurgery, Yokohama Sakae Kyosai Hospital, Yokohama, Kanagawa, Japan

Tetsuya Yamamoto

Department of Neurosurgery, Yokohama Sakae Kyosai Hospital, Yokohama, Kanagawa, Japan

Background and Purpose: Carotid artery stenting (CAS) is widely performed for the treatment of carotid artery stenosis. Postoperative kinking of the internal carotid artery (ICA) is occasionally observed; although usually benign, it may in rare cases result in complications such as embolism or vessel occlusion. While previous studies have suggested that the stylopharyngeus muscle can compress the ICA, its role in morphological changes before and after CAS, particularly in the development of kinking, has not been fully elucidated.

Materials and Methods: We retrospectively analyzed digital subtraction angiography (DSA) images from 17 patients who underwent CAS between May 2022 and March 2023. The segment from the carotid bifurcation (where the ICA and external carotid artery divide) to the entrance of the carotid canal was equally divided into nine sections, and eight reference points (Point 1 through 8) were defined in order from the bifurcation side. The amount of shift at each point was measured before and after CAS. Statistical analysis using Tukey’s honestly significant difference (HSD) test was performed to evaluate the significance of these positional changes. Additionally, anatomical dissection of two cadavers was performed in August 2023 at Yokohama City University Graduate School of Medicine to investigate the relationship between the stylopharyngeus muscle and the ICA.

Results: The analysis showed that minimal positional shifts were observed from Point 1 through 4, while significant shifts were noted from Point 6 through 8 (p < 0.001), suggesting vascular fixation around Point 5. In most cases, Point 5 corresponded to the region slightly proximal to the point where the ICA bends anteriorly. In one cadaveric specimen, the stylopharyngeus muscle was found to compress the ICA. Notably, the site of compression corresponded to Point 5 on imaging, supporting the radiological findings.

Conclusion: Compression by the stylopharyngeus muscle may serve as an anatomical fixation point for the ICA. Depending on the stent deployment site during CAS, kinking may occur as a result of the interaction between mechanical forces from stent-induced vessel deviation and this anatomical fixation. Preoperative recognition of such anatomical characteristics may facilitate the prediction and prevention of kinking, thereby contributing to improving the safety and outcomes of CAS procedures.

A-071

Evaluation of carotid plaque characterization using dual energy CT

Category: Other Head and Neck Pathologies

Primary Author

Sakyo hirai

Institute of Science Tokyo Japan

Co-Author

Takuya Watanabe

Institute of Science Tokyo

Shoko Fujii

Institute of Science Tokyo

Satoru Takahashi

Institute of Science Tokyo

Kyohei Fujita

Institute of Science Tokyo

Kazutaka Sumita

Institute of Science Tokyo

Background and Purpose: Dual energy CT (DECT) is useful for qualitative diagnosis of tissues by using the attenuation difference of material-specific CT values obtained by two types of X-ray energy. Although clinical applications are expanding, reports on the carotid plaque characterization are limited.

Materials and Methods: Of 52 cases in which carotid artery stenting (CAS) was performed at our hospital from June 2023 to March 2025, 34 cases and 38 lesions were evaluated using DECT images. Plaque characterization were evaluated by setting manual ROIs on the axial cross section of the most stenotic lesion, and measuring electron density (Rho), effective atomic number (Z), virtual non-contrast CT value (VNC), fat fraction (FF %), and iodine concentration (IC %). Each parameter was compared between two groups based on the presence or absence of symptoms of the lesion, and correlations with the sternocleidomastoid muscle ratio (rSI) of plaques using the MRI BB method were examined.

Results: Median age was 76 years (range 72-81), all patients were male, 13 patients (34.2%) had symptomatic lesions, and median stenosis rate was 76% (range 64-88). When examining each parameter according to the presence or absence of symptoms, Rho (28.6±6.5 vs 36.7±9.4, p<0.01) and VNC (21.8±6.7 vs 30.0±10.4, p<0.05) were significantly lower in symptomatic lesions, and FF% (22.3±4.6 vs 16.2±5.6, p<0.01) was significantly higher. There were no significant differences between symptomatic and asymptomatic patients in Z (8.19±0.38 vs. 8.16±0.52, p=0.50), IC% (13.4±8.4 vs. 12.5±8.8, p=0.63), and rSI (1.44±0.41 vs. 1.40±0.43, p=0.67). Multivariate analysis of each DECT parameter showed that FF% (OR; 0.68 [0.43 – 1.07], p=0.08) was a borderline significant predictor of symptomatic lesions. There were no significant correlations between rSI, angiographic ulceration, or postoperative DWI positivity rate of CAS and each DECT parameter.

Conclusion: Symptomatic lesions had lower CT values and higher fat fractions of plaques, but there was no difference in iodine concentration, which is considered to reflect neovascularization, compared with asymptomatic lesions. Although there was no correlation with rSI, which is an index of instability, it was suggested that DECT parameters, especially the fat fraction within the plaque, may be useful in predicting symptomatic lesions.

A-072

Transvenous embolization for dural arterio-venous fistula with isolated sinus

Category: Dural Arteriovenous Fistulae

Primary Author

Yasunobu Nakai

Yokohama City University Japan

Co-Author

Taisuke Akimoto

Yokohama City University

Yu Iida

Yokohama City University

Masao Kishimoto

Fujisawa City Hospital

Hiroshi Kushi

(Saiseikai Yokohamashi Nanbu Hospital

Tetsuya Yamamoto

Yokohama City University

Background and Purpose: Intracranial dural arteriovenous fistulas (DAVFs) with isolated sinus were associated with high hemorrhagic risk. However, packing of the infected sinus was considered to be a curative treatment, transvenous penetration for occluded sinus is difficult with under- reporting of their optimal approaches.

Materials and Methods: Retrospective analysis of adult patients with an isolated sinus DAVFs treated at our institution and affiliated hospital between March 2024 and April 2025. Of 5 patients with an isolated sinus DAVFs underwent treatment. Cases were analyzed for clinical presentation, neuroradiologic findings, treatment techniques, angiographic and clinical outcomes and complications.

Results: The median age was 75.4 and 3 were male. One patient presented with intracranial hemorrhage, 2 patients presented with convulsion, 1 patient present with pulsatile tinnitus, and 1 patient without symptom. Isolated sinus DAVFs were located at transverse ∼ sigmoid sinus in 4 patients, and 1 patient is cerebellar tentorium. To evaluate the occluded sinus using T1-weighted black-blood MRI, and transvenous navigation via the occluded sinus using tetraxial catheter system were successful in all cases. Only 1 case suffered subarachnoid hemorrhage due to perforation of dural sinus. All cases were treated by transvenous embolization using Onyx with/without coils, complete occlusion was achieved in all cases.

Conclusion: Careful evaluation of occluded sinus using T1-weighted black-blood MRI, and using a highly supportive tetraxial catheter system, transvenous embolization of isolated sinus DAVFs is possible without direct surgical venous sinus approach.

A-074

Precision Under Pressure: Dual Balloon Protection and Pressure Cooker Embolisation of a High Grade Sphenoid Wing Dural Arteriovenous Fistula.

Category: Dural Arteriovenous Fistulae

Primary Author

Yuh Yang Leong

Department of radiology/ hospital canselor tuanku Muhriz Ukm, Malaysia

Co-Author

Ahmad Azri Ahmad Shaifuddin

Department of Radiology/ Hospital Canselor Tuanku Muhriz Ukm

Farizal Fadzil

Division of Neurosurgery, Department of Surgery, Faculty of Medicine Ukm

Ahmad Fairuz Abdul Shokri

Department of Anaesthesiology and Intensive Care/ Hospital Canselor Tuanku Muhriz

Abdul Hakim Mohd Yusoff

Department of Radiology/ Hospital Canselor Tuanku Muhriz Ukm

Nazurai Mat Nor

Department of Radiology/ Hospital Canselor Tuanku Muhriz Ukm

Background and Purpose: Dural arteriovenous fistulas (DAVF) with cortical venous reflux carry a high risk for intracranial haemorrhage. Sphenoid wing DAVF often receives multi-source arterial supply from both the internal and external carotid systems, demanding strategies to avoid catastrophic non-target embolic migration. Reflux protection becomes the key. We report a novel case utilising dual balloon protection and the pressure cooker technique to safely achieve curative embolisation.

Materials and Methods: A 45-year-old man presented with left sided tinnitus and headache. Prominent cortical veins noted on MRI at the left temporal region. Digital subtraction angiography revealed a left sphenoid wing Cognard IV DAVF with arterial supply from the sphenoidal and cavernous branches of the left middle meningeal artery (MMA), the recurrent meningeal artery from the left ophthalmic artery, and branches from the meningohypophyseal trunk (MHT) and inferolateral trunk (ILT) of the left internal carotid artery (ICA). The fistula drained into an ectatic sphenoparietal sinus and superficial middle cerebral vein, confirming cortical venous reflux. To prevent reflux of embolic agent into critical branches, dual Eclipse 2L balloon protection was employed. One balloon was inflated within the cavernous ICA to protect the MHT and ILT, while a second was positioned in the 2nd–3rd segment of the ophthalmic artery to guard the recurrent meningeal artery. This set-up enabled full flow control and protection across both internal carotid and ophthalmic systems. A Sonic detachable microcatheter was navigated into the sphenoidal branch of the left MMA. The pressure cooker technique was applied using Optima coils to create a proximal plug, jailing the Sonic microcatheter, followed by controlled injection of Squid 18/12 copolymer to penetrate the fistula and into the foot of vein.

Results: Complete angiographic obliteration was achieved with no copolymer reflux into the ICA or ophthalmic artery. The patient’s symptoms resolved post embolisation and remained neurologically intact.

Conclusion: This case highlights the strategic reflux prevention using dual balloon protection in critical branches in high-risk DAVFs with dangerous anastomoses. When combined with the pressure cooker technique, this approach allows safe and precise embolisation in complex neurovascular lesion.

A-076

Association between spinal vascular malformation and spinal dysraphism: case series.

Category: Spinal vascular diseases

Primary Author

Abdullah Alhindi

Asan Medical Center, Saudi Arabia

Co-Author

Yunsun Song

Professor at Asan Medical Center, University of Ulsan College of Medicine

Background and Purpose: Several case reports document the association between spinal dysraphism, such as spinal lipoma and lipomyelomeningocele, and spinal vascular malformation, such as dural arteriovenous fistulae (DAVFs) and spinal arteriovenous malformation (AVM), suggesting a potential causal relationship. The incidence of spinal dysraphism worldwide is approximately 1 -3 in 1000 live births. To further investigate this connection, we present seven additional cases of spinal dysraphism coexisting with spinal vascular malformation.

Materials and Methods: We identified 304 patients with spinal dAVF and AVM from 2002 to 2024. Most of our patients have spinal dAVFs (240 patients), and the other 64 patients have spinal AVMs. All patients were treated, with most patients undergoing endovascular embolization, and a few patients were treated by open surgical resection of the vascular malformation. We identified seven cases of spinal dAVFs among our cohort of 304 patients with spinal dysraphism. Comprehensive analyses of imaging findings—including MRI and angiographic results—were conducted alongside assessments of clinical presentations, long-term outcomes, and treatment responses.

Results: The mean age of the patients was approximately 68 years, with a distribution of five females and three males. The most frequently observed spinal dysraphism was tethered cord syndrome, present in five patients, four of whom had accompanying intrathecal spinal lipomas, and three patients also showed associated dural ectasia—only one patient presented with lipomyelocele. The predominant symptom was motor weakness. MRI findings revealed vascular flow voids and increased signal intensities predominantly in the sacral and lumbar regions. The lateral sacral artery was the primary arterial feeder, with intradural perimedullary veins as the main drainage pathway. Treatment outcomes varied significantly, with three patients undergoing initial embolization followed by surgery, another three undergoing endovascular embolization only, and one undergoing surgical treatment with a good outcome following treatment in most patients.

Conclusion: In our study of 304 patients with spinal vascular malformations, we found a prevalence of 2.30% for associated spinal dysraphism, significantly higher than the global incidence of 0.1% to 0.3%. This suggests a potential association between the two conditions.

A-080

Spinal Dural and Epidural AVF Treatment Outcomes: Angiographic Cure and Functional Recovery

Category: Spinal vascular diseases

Primary Author

Raweenut Beangklang

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand, Thailand

Co-Author

Ekawut Chankaew

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand 2 Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand

Anchalee Churojana

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand

Thaweesak Aurboonyawat

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand 2 Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand

Churojana ngkapassakorn

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand 2 Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand

Boonrerk Sangpetngam

Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital

Background and Purpose: Spinal arteriovenous fistulas (AVFs), encompassing dural (DAVF), epidural (EDAVF), and complex multifocal variants, represent an underrecognized but potentially reversible cause of progressive myelopathy. Despite advances in diagnostic imaging, treatment outcomes remain unpredictable, particularly in anatomically complex lesions. This study reports the outcomes of spinal AVFs treated at Siriraj Hospital, utilizing a lesion-specific, angioarchitecture-guided strategy refined over a 16-year period.

Results: A retrospective review of 61 patients treated between 2007 and 2023 was conducted, comprising 48 DAVFs, 8 EDAVFs, and 5 multiple AVFs (including DAVF with perimedullary AVF × 1, DAVF with EDAVF × 3, and DAVF with filum AVF × 1). Treatment selection endovascular (60%), microsurgical (30%), or combined (11%) was guided by feeder selectability and the presence of ASA/PSA origin. Results: The median age was 58 years, with 66% male predominance. Clinical presentations included motor weakness (85%), numbness (65%), pain (50%), and bladder/bowel dysfunction (56%), without hemorrhagic events. Thoracic location was most common (42%), and 23% exhibited multiple feeders. No aneurysms were detected, while venous pouches were identified in one DAVF and one EDAVF case. The median mALS at presentation was 7. NBCA was used in 95% of endovascular cases. Surgical intervention was required in 41% due to anatomical inaccessibility (n=8) or high-risk feeders (ASA n=8, PSA n=4). An- giographic cure was achieved in 89.8%, reaching 98% among DAVFs. Post-treatment MRI demonstrated significant radiologic improvement, with median T2 hyperintensity reduced from 7 levels to 0 and complete resolution of flow voids (p=0.041). Functional improvement occurred in 80%, with complete recovery in 19%. Motor weakness improved in 92% of cured and 79% of improved cases. Motor weakness at presentation correlated with favorable outcomes (p<0.001), while residual T2 hyperintensity >3 levels predicted poor prognosis (OR 0.00, p=0.059). The complication rate was 6.8%, two feeder extravasations (DAVFs), and two glue migrations into perimedullary veins (DAVFs). Post-treatment medications were required in 45% (heparin 26%, dexamethasone 19%). None of the complications resulted in permanent neurological deficits.

Conclusion: A lesion-specific, angioarchitecture-guided strategy achieved durable angiographic cures and substantial functional recovery in spinal AVFs. Early diagnosis and radiologic reversibility are critical prognostic factors, supporting individualized hybrid treatment as a new standard of care.

A-086

Ruptured of Flow related Aneurysm in Dural Arteriovenous Fistula Supplied by the Artery of Wollschlaeger and Wollschlaeger and Bernasconi-Cassinari Artery : A rare case.

Category: Dural Arteriovenous Fistulae

Primary Author

intan sudarmadi

Department of Neurology Dokter Mohamad Saleh Hospital and Fellowship in Vascular Neurointervention, Dr Soetomo Academic Medical Center Hospital, Surabaya, Indonesia Indonesia

Co-Author

Ahmad Firdaus Sani

Neurointervension Division, Department of Neurology Airlangga University, Dr Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Dedy Kurniawan

Neurointervension Division, Department of Neurology Airlangga University, Dr Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Putu Yudhi Nusartha

Department of Neurology, Mulawarman University, Abdoel Wahab Sjahranie Hospital, and Fellowship of Vascular Neurointervention Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Soni Azhar Pribadi

Department of Neurology, Ngudi Waluyo Wlingi General Hospital, and Fellowship of Vascular Neurointervention Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Shakir Husain Hakim

Stroke and Neurointervention Foundation (SNIF), New Delhi, India

Background and Purpose: Subarachnoid hemorrhage (SAH) caused by ruptured intracranial aneurysm is a life-threatening condition. Flow-related aneurysms associated with underlying vascular malformations such as dural arteriovenous fistulas (DAVFs) represent a rare cause of hemorrhage. The artery of Wollschlaeger and Wollschlaeger (AWW), a deep cerebellar branch of the superior cerebellar artery, is an extremely uncommon site for aneurysm formation. When hemodynamic stress from DAVFs involves such distal vessels, it may lead to the rupture of flow-related aneurysms. These cases are particularly challenging due to the deep vascular location, diagnostic difficulty, and limited access for treatment. Prompt identification and targeted endovascular therapy are crucial to prevent rebleeding and ensure favorable outcomes.

Results: We report the case of 34 y.o. male patient with acute subarachnoid hemorrhage. Digital subtraction angiography revealed a DAVF supplied by two rare feeders: the AWW (a cerebellar branch of the superior cerebellar artery)and the Bernasconi-Cassinari artery (a dural branch of the internal carotid artery). Venous drainage was observed into cortical, cerebellar, and deep venous systems. Additionally, a ruptured flow- related aneurysm was identified on the AWW, measuring 3.80 mm at the neck and 7.78 mm in height with a width of 3.89 mm. Endovascular access was established through the left vertebral artery (V3 segment) using a Fargo 6F guiding catheter. A Magic 1.5 microcatheter, navigated with a Hybrid 007D microwire, was advanced into the AWW adjacent to the fistulous site. Embolization was performed using n-butyl cyanoacrylate (NBCA) mixed with Lipiodol at concentrations of 20% and 30%. Post-procedural angiography demonstrated complete occlusion of both the fistulous site and the flow related aneurysm. The patient recovered well with no new neurological deficits. Follow-up imaging at three months confirmed durable occlusion and absence of recurrence.

Conclusion: This case showed a very rare ruptured flow related aneurysm in arterial feeders of DAVFs by the AWW with another feeder from the Bernasconi-Cassinari artery. Complete obliteration is reached by embolize the AWW.

A-089

A case of choroidal type Vein of Galen Aneurysmal Malformation presenting with subarachnoid hemorrhage in adulthood during follow-up

Category: Pediatric Vascular diseases

Primary Author

Kotaro Ueda

Kameda Medical Center Japan

Co-Author

Shimpei Tsuboki

Kumamoto University Hospital

Takafumi Mitsutake

Kameda Medical Center

Keisuke Kadooka

Kameda Medical Center

Michihiro Tanaka

Kameda Medical Center

Background and Purpose: Vein of Galen aneurysmal malformation (VGAM) accounts for approximately 1% of all intracranial vascular malformations, with only a few cases approximately up to five reported annually in Japan. The choroidal type VGAM is characterized by a primitive vascular architecture, in which the aneurysmal sac is connected to a network of arteries within the cistern. This subtype poses significant challenges to curative treatment, and often managed palliatively with repeated transarterial embolization (TAE) during follow-up. Currently, there is no established evidence regarding the optimal timing for additional interventions in such cases, and treatment decisions are often made at the discretion of the attending physician based on the individual clinical course.

Results: A 20-year-old male with a history of choroidal type VGAM, who had undergone multipleTAEs during infancy at another institution and was followed with MRI, presented with sudden headache and vomiting. CT scan revealed diffuse subarachnoid hemorrhage along with ventriculomegaly. Digital subtraction angiography under general anesthesia demonstrated numerous feeding arteries, and feeder aneurysm was identified on both the right quadrigeminal artery and the left subforniceal artery. Based on the hemorrhage distribution, the aneurysm on the right quadrigeminal artery was considered the likely source of bleeding. Subsequently, TAE using n-butyl cyanoacrylate (NBCA) was performed. A total of six major feeding arteries, including the two with feeder aneurysms, were embolized. The postoperative course was uneventful, and the patient was discharged home on postoperative day 17. Retrospective review of follow-up imaging from the previous institution revealed progressive stenosis of the left transverse sinus over the preceding years, which had progressed to complete occlusion on MRI one month prior to the hemorrhagic event. Additionally, although not previously noted, retrospective analysis revealed the emergence of micro-feeder aneurysms on MR images several years earlier.

Conclusion: Progressive stenosis or occlusion of major venous sinuses and the emergence of feeder aneurysms may reflect worsening of the arteriovenous shunt pathology in VGAM. However, it can be challenging to detect small feeder aneurysms using routine MRI. When progressive findings are observed during regular MRI follow-up, cerebral angiography should be considered to evaluate for the presence of aneurysms. If identified, prophylactic embolization may be warranted to prevent hemorrhagic complications.

A-096

Three-Dimensional Mapping of ICA Remodeling After Flow Diverter Deployment: The Role of ICA segments and Pre-treatment Angulation

Category: Cerebral Aneurysm

Primary Author

I-Chang Su

Shuang-Ho Hospital, Taipei Medical University Taiwan

Co-Author

Shun-Tai Yang

Shuang-Ho Hospital, Taipei Medical University

Yu-Jui Fan

School of Biomedical Engineerin, Taipei Medical University

Jia-Hung Chen

Shuang-Ho Hospital, Taipei Medical University

Yi-Chen Hsieh

Taipei Medical University

Yu-Chun Lu

Shuang-Ho Hospital, Taipei Medical University

Background and Purpose: Flow diverters (FDs) are increasingly used for internal carotid artery (ICA) aneurysms, yet the extent and direction of FD-induced remodeling along ICA segments remain poorly characterized. This study aimed to assess segment-specific and angulation- dependent remodeling of the ICA and its branches using high-resolution three-dimensional imaging, with implications for treatment planning and device performance.

Materials and Methods: A retrospective analysis was conducted on 69 patients (72 aneurysms) treated with the Pipeline Embolization Device (PED). Pre- and post-treatment subtracted cone-beam CT angiography was used for centerline-based modeling of the ICA and its major branches. Twelve angular measurements were recorded at branch points and bifurcations. Remodeling patterns were evaluated across segments and stratified by tertiles of pre-treatment angulation. Linear mixed- effects models assessed the effects of device coverage and baseline angulation on angular change.

Results: The mean cumulative angular change across the ICA was 33.84° ± 21.77°. Distal segments (i.e. junction between ophthalmic and PcomA segments of ICA [ICA_oph_PcomA] and junction between PcomA and anterior choroidal artery segments of ICA [ICA_ PcomA_AChA]) contributed significantly more to total change than the cavernous/ophthalmic segment (p = 0.002). Remodeling direction was bidirectional and related to baseline curvature: segments with low pre-treatment angulation straightened (ICA_oph_ PcomA: +12.14°, ICA_PcomA_AChA: +12.06°), while those with high angulation became more curved (ICA_ oph_PcomA: −9.50°, ICA_PcomA_AChA: −11.22°). Branch vessels, including the PcomA, AChA, and ICA bifurcation, showed similar angulation-dependent remodeling. Changes also occurred beyond the stented segment. Meanwhile, Significant negative correlations were found between ICA segment remodeling and corresponding branch takeoff angles, suggesting coordinated geometric adaptation.

Conclusion: FD-induced ICA remodeling is not uniformly straightening but varies by segment and baseline angulation. Distal ICA segments remodel more, and angulation extremes predict directionality. Recognition of these patterns may refine pre-procedural planning, device selection, and branch outcome prediction. Further research is warranted to determine the clinical implications of these geometric changes.

A-097

Impact of Magnified 3D Rotational Angiography on Eye Lens Radiation Dose and Image Quality: A Phantom and Pilot Cohort Study

Category: Others

Primary Author

Ahmed Albaqshi

Asan Medical centre Saudi Arabia

Co-Author

Yunsun Song

Asan Medical centre

Deok Hee Lee

Asan Medical centre

Boseong Kwon

Asan Medical centre

Abdullah Alhindi

Asan Medical centre

Background and Purpose: Background: Radiation-induced cataract is a documented risk during neurointerventional imaging. Optimizing 3D rotational angiography (3DRA) protocols specifically through magnification may reduce lens exposure without sacrificing diagnostic image quality. However, the clinical impact of varying field-of-view (FOV) settings remains underexplored. Objective: This study aims to evaluate whether 3DRA performed with a 22 cm, 32 cm magnified FOV reduces eye lens radiation dose compared to the conventional 42 cm FOV, while maintaining diagnostic accuracy.

Materials and Methods: A two-phase study is conducted using the Siemens Artis Q biplane angiography system (Siemens Healthineers, Germany). In the initial phantom study, lens doses and Dose-Area Product (DAP) data were compared across 22 cm and 42 cm settings, revealing a consistent reduction with magnification. In the clinical phase, patients undergoing bilateral 3DRA—based on prior MRA or CTA—are prospectively enrolled. After acquiring an informed consent, each patient will undergo two acquisitions, randomly assigning one hemisphere to each FOV. A single experienced operator performs all procedures to ensure consistency. A 3 photoluminescent glass dosimeter (PLD) are attached to each eyelids to measure the actual lens dose, while DAP values will be recorded. Image quality will be assessed using both objective resolution metrics and a blinded 5-point scale evaluating diagnostic confidence will be done by three experienced interventional neuroradiologists.

Results: Phantom results support a dose reduction with 22 cm magnification. Three patients were studied in our pilot, resulting in a 33.9% reduction in radiation dose to the lens ipsilateral to the lesion of the exam interest, and a 62.2% reduction to the contralateral lens, validating the phantom findings and confirming the clinical feasibility of magnified 3DRA protocols. An additional 17 patients are planned to complete the cohort of 20 patients. The image quality assessment showed no significant difference between both acquisitions.

Conclusion: Use of a 22 cm FOV during 3DRA on the Siemens Artis Q system may significantly reduce eye lens radiation exposure without compromising image quality or diagnostic confidence. These findings could inform safer imaging strategies in neurointerventional procedures.

A-102

Filum Terminale Arteriovenous Fistula in Association with Degenerative Lumbosacral Spinal Canal Stenosis: Report of 3 Cases and Review of the Literature

Category: Spinal vascular diseases

Primary Author

Prasert Iampreechakul

Neurological Institute of Thailand Thailand

Co-Author

-

Background and Purpose: Filum terminale arteriovenous fistulas (FTAVFs) are rare spinal vascular lesions, typically located below the conus medullaris and classified as type IVa perimedullary AVFs. While some FTAVFs are considered congenital, growing evidence suggests that they may arise secondary to degenerative spine disease, particularly lumbar spinal canal stenosis. Recognizing this acquired mechanism is essential for appropriate diagnosis and treatment. This study aims to present three cases of FTAVFs associated with severe lumbosacral spinal canal stenosis, highlighting the clinical, radiological, and angiographic features, as well as the outcomes following surgical or endovascular treatment. A focused literature review is also performed to contextualize these findings.

Results: All three patients presented with progressive myelopathy and bowel/bladder dysfunction, following a history of low back pain, sciatica, or intermittent claudication. MRI and spinal angiography revealed FTAVFs located at or just caudal to the levels of maximal spinal stenosis. Two patients underwent successful surgical treatment, including decompressive laminectomy, instrumented fusion, and direct fistula obliteration. These patients achieved good neurological recovery and radiological resolution of spinal cord congestion. One patient underwent unsuccessful embolization and declined further surgery, resulting in poor clinical outcome. Review of 17 additional published cases revealed that most FTAVFs associated with spinal stenosis were located at corresponding levels and were effectively managed by surgical intervention.

Conclusion: Our findings support the hypothesis that FTAVFs can be acquired lesions secondary to chronic mechanical and inflammatory changes from severe lumbar spinal canal stenosis. MRI with contrast and spinal angiography remain essential for diagnosis. Surgical obliteration combined with decompression provides optimal results and should be considered the first-line approach in these cases. Early identification is critical to prevent irreversible neurological decline, especially in patients initially misdiagnosed with degenerative spine disease alone.

A-105

Deep Learning-Based Automated DWI Infarct Area Identification for Mechanical Thrombectomy Decision Support in Acute Ischemic Stroke

Category: Others

Primary Author

Wittawat Takong

Bangkok Pattaya Hospital Thailand

Co-Author

Kwankamon Dittakan

College of Computing, Prince of Songkhla University Phuket Campus, Phuket, Thailand

Nattakarn Buranakul

Neuroscience Center, Bangkok Pattaya Hospital, Chonburi, Thailand

Sirinat Puengcharoen

Neuroscience Center, Bangkok Pattaya Hospital, Chonburi, Thailand

Benjamas Boonyawan

Neuroscience Center, Bangkok Pattaya Hospital, Chonburi, Thailand

Background and Purpose: Acute ischemic stroke is a major cause of death and disability worldwide. Timely identification of patients eligible for Mechanical Thrombectomy (MT) is critical to improving outcomes, particularly within the extended 4.5–24-hour window. Diffusion-weighted imaging (DWI), an MRI technique sensitive to water molecule movement, allows visualization of infarcted brain tissue. The infarct core volume derived from DWI (DWI volume infarction) is essential in guiding MT decisions, as supported by the DAWN and DEFUSE-3 trials. Manual infarct volume estimation is effective but time-consuming and operator-dependent. Clinicians commonly use adapted prostate volume software for DWI-based assessments, which provide results in 3–5 minutes per patient. However, increasing clinical demand and the emergence of stroke care emphasize the need for faster, automated solutions to improve workflow efficiency, reduce variability, and support rapid decision-making in acute stroke management.

Materials and Methods: The automated approach aims to reduce inter- observer variability, improve diagnostic efficiency, and support timely clinical decision-making for MT. By integrating advanced AI techniques into stroke imaging workflows, this study seeks to enhance patient triage, optimize treatment allocation, and ultimately improve neurological outcomes in acute stroke management. Schematic framework for Automated DWI Infarct Area Identification using Deep Learning is presented in Figure 1. There are three different models have been generated for three different purposes include: (i) infarction classification model to distinguish between Normal and Infarct DWI images, (ii) artifact classification is used for classifying the artifact and non-artifact images, and (iii) infarction segmentation to identify the infarction area.

Results: The results from the experiments showed that the infarction image classification model achieved 94.28% accuracy using VGG16 architecture. The artifact image classification obtained 94.06% accuracy utilizing the VGG16 architecture. Finally, for infarction image segmentation, the model achieved a 77.35% validation Dice coefficient in identifying the location and area of infarction lesions. This combines two architectures by using VGG16 as the encoder and UNET as the decoder, which improves segmentation efficiency.

Conclusion: These results illustrate the capacity to improve diagnostic efficiency, reduce inter-observer variability, and accelerate clinical decision-making for MT in emergent stroke therapy.

A-111

Ten-Year Experience in the Management and Outcomes of Ruptured Cerebral Arteriovenous Malformations at Siriraj Hospital

Category: Cerebral Arteriovenous Malformation

Primary Author

Siriprapa Monsathaporn

Siriraj Hospital Thailand

Co-Author

Pattarawit Withayasuk

Siriraj Hospital

Boonrerk Sangpetngam

Siriraj Hospital

Thaweesak Aurboonyawat

Siriraj Hospital

Ekawut Chankaew

Siriraj Hospital

Anchalee Churojana

Siriraj Hospital

Background and Purpose: Ruptured cerebral arteriovenous malformations (AVMs) present significant clinical challenges, with outcomes influenced by AVM characteristics, and treatment modalities. This study aims to describe the clinical profiles, angiographic risk factors, and therapeutic outcomes of ruptured cerebral AVMs treated at Siriraj Hospital.

Materials and Methods: A retrospective review was conducted on patients diagnosed with ruptured cerebral AVMs at Siriraj Hospital between January 2014 and March 2024. Data collected included patient demographics, AVM characteristics, angiographic risk factors, treatment modalities, and outcomes.

Results: A total of 129 patients were identified. The majority of patients (84.4%) were older than 15 years at the time of angiographic diagnosis, with a mean age of 32.8 years. AVM location was mainly lobar (63.6%), with 36.4% located in deep brain regions. Deep venous drainage was present in 61.2% of cases. Spetzler-Martin grades 2 and 3 accounted for 59.7%, indicating moderate surgical risk. Angiographic risk factors were common: intranidal aneurysms (24.8%), venous pouches (12.4%), and venous stenosis (15.5%). Multimodality treatment was applied in 37.2% of patients, while embolization alone was performed in 27.1%. Among 81 patients who underwent embolization, targeted or partial embolization was performed in 68 cases (83.95%), while curative embolization was achieved in 13 cases (16.04%), resulting in a low re-rupture rate of 6.17%. Conservative management was used in 7% of cases.

Conclusion: This review demonstrates that ruptured cerebral AVMs predominantly affect young adult patients, with lobar location and deep venous drainage frequently observed. Multimodality treatment was the most common approach, and embolization showed a low re-rupture rate. These findings provide valuable insights into the clinical and angiographic profiles of ruptured cerebral AVMs in a tertiary care setting, which may guide future management.

A-001

Relationship between in-stent restenosis following carotid artery stenting and platelet reactivity to clopidogrel

Category: Acute Ischemic Stroke

Primary Author

Min-Yong Kwon

Keimyung University School of Medicine South Korea

Co-Author

Sang Hyo Lee

Seoul National University Bundang Hospital

Yongjae Lee

Seoul National University Bundang Hospital

Young Deok Kim

Seoul National University Bundang Hospital

O-Ki Kwon

Seoul National University Bundang Hospital

Seung Pil Ban

Seoul National University Bundang Hospital

Background and Purpose: The quantitative association between in-stent restenosis (ISR) and platelet function in patients treated with carotid artery stenting (CAS) remains poorly documented. We aimed to evaluate the degree of ISR following CAS using computed tomographic angiography (CTA), examine its relationship with platelet reactivity to clopidogrel, and determine the optimal thresholds of the P2Y12 reaction unit (PRU) and inhibition rate (IR) for identifying ISR.

Materials and Methods: We retrospectively analyzed 171 patients who underwent CAS with extracranial carotid stenosis from January 2016 to December 2019. Dual antiplatelet therapy with 100 mg aspirin and 75 mg clopidogrel was started ≥5 days before CAS. Clopidogrel resistance was measured with the PRU and IR the day before CAS. The ISR degree was classified into R1 (mild luminal stenosis of <50% ranging <50% of the stented carotid artery total length), R2 (mild luminal stenosis of <50% ranging ≥50% of the stented carotid artery total length), and R3 (moderate to severe luminal stenosis of ≥50% or occlusion) through carotid CTA after 24-30 months. The quantitative association degree between platelet reactivity and ISR R3 was determined by the receiver operating characteristic curve method. The optimal cutoff values of PRU and IR were derived using the maximum Youden index.

Results: There were 33 ISR of R3s (19.3%) and 9 ipsilateral ischemic strokes (5.3%). The PRU and IR were different between R1 + R2 (176.4 ± 50.1, 27.5 ± 18.7%) and R3 (247.5 ± 55.0, 10.3 ± 13.4%) (p<0.001). The areas under the curves of PRU and IR were 0.841 and 0.781, and the optimal cutoff values were 220.0 and 14.5%, respectively. Multivariate logistic regression analysis showed that PRU ≥220 and IR ≤14.5% were significant predictive factors for ISR R3 (p<0.001, p=0.017). ISR R3 was independently associated with ipsilateral ischemic stroke after CAS (p=0.012).

Conclusion: High PRU (≥220) and low IR (≤14.5%) are related to ISR R3 following CAS, which may cause ipsilateral ischemic stroke. This is the first observational study to address the relationship between ISR following CAS and platelet reactivity to clopidogrel. Long-term ISR follow-up and modified antiplatelet preparation to improve ISR seems to be needed in patients with high clopidogrel resistance.

A-002

Initial usage experience of JOIN smartphone application in NHO Sendai Medical Center

Category: Others

Primary Author

Masayuki Ezura

NHO Sendai Medical Center Japan

Co-Author

Kenichi Sato

NHO Sendai Medical Center

Background and Purpose: Our hospital provides neuro emergency services on a 24-hour basis. The staff on duty at night are not necessarily specialists in neurosurgery or interventional neuroradiology. The decision to proceed with surgical intervention including mechanical thrombectomy requires the judgment of these specialists. Therefore, we introduced JOIN smartphone application as a smooth means of communication with specialists. The purpose of this study is to show the initial usage experience of JOIN.

Materials and Methods: When the on-call physician determines that surgical intervention may be necessary, they upload the relevant information to JOIN and simultaneously contact the on-duty specialist by phone to assess the need for surgical intervention.

Results: In the 10 months following the introduction of JOIN, there were 146 days when the on-call physician was not a specialist. There were 89 cases where imaging consultations occurred via JOIN. These cases, which involved hemorrhagic conditions, would traditionally require a specialist to come to the hospital to review the images directly or to make judgments based on unclear images taken with a mobile phone camera. Although the images reviewed on JOIN are displayed on a small smartphone screen, they are sufficiently clear for assessing hemorrhagic lesions. For ischemic lesions, the resolution may not be adequate, but when combined with Rapid processing of PerfusIon and Diffusion (RAPID) software, it becomes possible to make a judgment

Conclusion: By introducing JOIN, it has become possible to assess the need for surgical intervention on a smartphone, thereby reducing the time to initiate treatment. For ischemic lesions, if you have RAPID software, it becomes possible to make a judgment. Additionally, the number of times specialists were required to come in outside of regular hours has significantly decreased.

A-003

Imaging Features and Treatment Strategies for Symptomatic Carotid Web: A Case Series Study

Category: Acute Ischemic Stroke

Primary Author

Yohei Tanaka

Department of Neurology, Tachikawa General Hospital Japan

Co-Author

Hiroki Takano

Department of Neurology, Tachikawa General Hospital

Shinichi Katada

Department of Neurology, Tachikawa General Hospital

Jun Tsukano

Department of Neurosurgery, Tachikawa General Hospital

Toshiharu Nomura

Department of Neurosurgery, Tachikawa General Hospital

Hiroshi Abe

Department of Neurosurgery, Tachikawa General Hospital

Background and Purpose: Carotid web (CW) has been identified as one of the embolic sources in embolic stroke of undetermined source (ESUS), but its presence is often overlooked. Regarding treatment, it has been reported that medical therapy alone results in frequent recurrences. Surgical revascularization has been reported as a more effective treatment for symptomatic CW, although high-quality evidence is lacking. We present cases of symptomatic CW encountered at our hospital and discuss diagnostic and management strategies.

Materials and Methods: We selected cases of symptomatic CW from patients with cerebral infarction admitted to our department between November 2016 and December 2024 and examined their clinical characteristics.

Results: Five cases of symptomatic CW were identified, with a median age of 47 years. All patients were female, and all presented with ipsilateral middle cerebral artery occlusion. Mechanical thrombectomy was performed in three cases. Regarding diagnosis, neck time-of-flight MR angiography was difficult to interpret in all cases. Carotid duplex was suggestive of CW in two cases, where blood clots were suspected to be adhering to the CW. CT angiography (CTA) or catheter cerebral angiography (CAG) was required for a definitive diagnosis. Multi-planar reconstruction was particularly useful for obtaining detailed images of the CW’s structure. Vessel wall MRI was helpful in identifying CW in four cases. In terms of treatment, three patients underwent CAS, and two patients were managed with antiplatelet therapy alone. All patients who underwent CAS were treated with open-cell stents, which have been reported to cause less postoperative restenosis compared to closed-cell stents. The stent was successfully deployed without any troubles in all CAS cases. No post-treatment recurrences were observed in any of the cases.

Conclusion: Accurate diagnosis of CW relies on recognizing its presence, particularly in young female patients. CTA or CAG is essential for diagnosing CW when it is considered a potential embolic source of cerebral infarction. While carotid duplex is less sensitive, it may reveal clots adhering to the CW. In terms of treatment, both medical therapy and CAS demonstrated good outcomes in this study. CAS using an open-cell stent is considered safely feasible. Further studies with larger sample sizes are needed.

A-006

Recanalization is Not Always Equate to Reperfusion: No-Reflow Phenomenon after Successful Thrombectomy as a Predictor for Futile Recanalization and Hemorrhagic Transformation in Major Vessel Occlusion

Category: Acute Ischemic Stroke

Primary Author

Nobutaka Horie

Hiroshima University Japan

Co-Author

Takeshi Hara

Masashi Kuwabara

Hiroshi Kondo

Daizo Ishii

Background and Purpose: Thrombectomy for acute major vessel occlusion is a well-established procedure for preventing stroke. However, cases of futile recanalization, where tissue no-reflow persists despite successful reperfusion, have been observed. The aim of this study is to assess cerebral hemodynamics immediately after successful thrombectomy regarding clinical outcome.

Materials and Methods: We prospectively registered cases that achieved successful thrombectomy (mTICI>2b) for anterior circulation. Pre-operative evaluation included MR imaging. Thirty minutes after recanalization, flat panel CT perfusion imaging was performed, and CBF, CBV, Tmax, mismatch ratio and hypoperfusion index were calculated with Rapid ANGIO. We examined the correlation of these parameters with infarct expansion, hemorrhagic transformation and clinical outcome.

Results: Analysis was conducted on 65 consecutive cases with successful recanalization. Infarct expansion occurred in 23 cases (35.4%), with a significantly lower percentage of susceptibility vessel sign, higher CBF<45% area, and lower favorable clinical outcome. CBF<45% area, not Tmax>6s, significantly correlated with final ASPECTS. Interestingly, mismatch ratio was higher in the group without infarct expansion (p<0.001). Hemorrhagic transformation occurred in 26 cases. The groups with hemorrhagic transformation showed a higher CBF<45% and CBV<34% area (both p=0.01), and hypoperfusion index was also higher (p<0.001). These post-operative parameters significantly contributed to clinical outcome three months after onset.

Conclusion: No-reflow phenomenon could be detected after successful thrombectomy with flat panel CT perfusion, suggesting that major vessel recanalization does not necessarily equate to immediate tissue reperfusion. Our study highlights post-thrombectomy hemodynamic mismatch and collaterals as potential indicators for the quality of thrombectomy.

A-008

Effectiveness and Outcomes of Proximal Balloon Occlusion versus Distal Filter for Embolic Protection during Carotid Artery Stenting

Category: Other Head and Neck Pathologies

Primary Author

Seung Young Chung

Daejeon Eulji Medical Center South Korea

Co-Author

Hyun Dong You

Daejeon Eulji Medical Center

Background and Purpose: CAS is rapidly alternative to CEA and even more effective for high-risk cases. The main concern is preventing procedural embolus dislodgement and so preventative embolic protection devices (EPDs) have significantly improved prognosis

Materials and Methods: This retrospective study included all 106 patients with symptomatic or asymptomatic ICA stenosis ≥70% treated with CAS with either of 2 EPDs: distal filter protection device (DFP) or proximal balloon occlusion device (PBO). All underwent pre- and post DWI to detect new ischemic lesions. We compared clinical outcomes and postprocedural embolization rates in both.

Results: In 111 cases with CAS, DFP success rate was 98.4% and subsequent DWI revealed 249 new ischemic lesions in 81%. In contrast, PBO was 91.4% and 71 new ischemic lesions in 58%. No differences were observed in success rate. PBO resulted in lower new ischemic lesions (p=0.031). PBO also showed fewer total new ischemic lesions (p=0.002) and new ischemic lesions per patient (p=0.027). And in ≥3 new ischemia, significantly lower rate in PBO (p=0.002). In the subtype of stent, there is no significant interaction effect between stent and EPDs and type of stent also did not affect the number of new ischemic lesions. Complications occurred in 1 for DFP and 3 for PBO but all improved

Conclusion: The incidence of postprocedural ischemic lesions was lower in PBO than DFP. And the total number and new ischemic lesions per patient on DWI were also lower in PBO. So, as compared with DFP, PBO might be more effective in reducing cerebral embolism during CAS

A-009

Retrograde angiography in dissecting vertebral artery aneurysms to avoid intraoperative rupture

Category: Cerebral Aneurysm

Primary Author

Masahiro Nishihori

Nagoya University Japan

Co-Author

Takashi Izumi

Nagoya University

Shunsaku Goto

Nagoya University

Hana Ichinose

Nagoya Institute of Technology Graduate School of Engineering

Masanori Nakamura

Nagoya Institute of Technology Graduate School of Engineering

Ryuta Saito

Nagoya University

Background and Purpose: Vertebral artery dissection (VAD) is often treated with endovascular therapy. However, when contrast media is injected, pressure is applied to the vessel wall. In cases where the vessel wall is fragile, intraoperative rupture may occur. We have devised a method to reduce pressure on the vessel wall by performing retrograde angiography. To verify this scientifically, we conducted an experiment in vitro.

Materials and Methods: For retrograde angiography, a balloon guide is first placed in the diseased vessel, and the balloon is inflated to block the antegrade blood flow. By releasing the three-way stopcock at hand, the blood flow is drained retrogradely while taking an angiogram from the opposite side. To verify the results in actual clinical practice and this method, we attached a pressure sensor using a silicone tube and verified it in a pulsatile model that applies similar body blood pressure to that in vivo.

Results: From October 2022, when we started using this method, to the end of 2024, we treated 8 cases of ruptured VAD in 10 sessions. In 4 of these cases, we performed retrograde contrast, and in all cases we were able to obtain sufficient DSA and 3DRA images, and we were able to complete internal trapping. In 1 case, we performed antegrade imaging manually once, and intraoperative rupture occurred. In vitro experiments showed that when anterograde angiography was performed, the pressure on the aneurysm wall was 1.3-2 times higher than the systemic blood pressure, but when retrograde angiography was performed, the pressure increase on the contrast side was 1.3-2.1 times higher, while the pressure increase on the affected side was 1.15-1.87 times higher, a 10-23% reduction in the pressure increase range.

Conclusion: Retrograde angiography was safe and provided sufficient image quality in the acute treatment of dissecting vertebral artery aneurysms. Vitro experiments also demonstrated that it sufficiently reduced pressure on the vessel wall, and it could be a radiographic technique that contributes to further safety improvements.

A-010

A Case of Ruptured Distal Middle Cerebral Artery Aneurysm with Metastatic Bladder Cancer

Category: Cerebral Aneurysm

Primary Author

Sung-Kyun Hwang

Ewha Womans University of College of Medicine, Mokdong Hospital, South Korea

Co-Author

-

Background and Purpose: We report a case of ruptured middle cerebral artery aneurysm with metastatic bladder cancer treated by endovascular embolization.

Materials and Methods: A 54-year-old man presented with seizure and followed by loss of consciousness. Brain computed tomography examination revealed acute intracerebral hemorrhage (ICH) with perilesional edema in the left parietal area, associated with multifocal subarachnoid hemorrhage (SAH). Cerebral angiography also showed that lobulating aneurysm at the left M4 branch in the left parietal area. Brain magnetic resonance image showed that mutifocal diffusion-high signal lesions with partly nodular cortical enhancement and multiple microbleeds and SAH in the both cerebral hemispheres representing multifocal acute to subacute embolic infarctions..

Results: Postoperative angiography showed the obliteration of aneurysm sac preserving branch artery in the neck portion. He had past medical history of metastatic bladder cancer treated by chemotherapy. He made a steady recovery without neurological sequela after operation. Follow-up CT or image study showed the resolving state of ICH without an additional intracranial lesion.

Conclusion: Further investigations are needed to reveal risk factors, physiology and causative mechanisms of this phenomenon of aneurysmal formation and rupture in patient with metastatic cancer.

A-011

Unmasking Occult Ruptured Aneurysm in Acute Subarachnoid Hemoorhage with Previously Unknown Etiology: Successful Treatment with Flow Diversion and Coiling

Category: Cerebral Aneurysm

Primary Author

Gamaliel Soetanto

Saint Borromeus General Hospital Indonesia

Co-Author

Jani Heriwidajani

Saint Borromeus General Hospital

Background and Purpose: Ruptured brain aneurysm is the most common cause of acute spontaneous subarachnoid hemorrhage (SAH). It is a medical emergency, predominantly affecting individuals of productive years, with prehospital and in hospital mortality rate of 26% and 13%, respectively. Brain angiographic computed tomography (CTA) exhibits sensitivity of 97.2% for detecting ruptured aneurysms, which decreases to 61% for small aneurysms (diameter <5 mm). As gold standard, digital subtraction angiography (DSA) had better sensitivity of 98.1%, which decreases to 90.9% for small aneurysms. This report emphasized the importance re-evaluating the possibility of brain aneurysm in SAH with unknown etiology. Furthermore, combination of flow diverter (FD) and coiling was safe to be employed in the acute phase of SAH.

Materials and Methods: This report presented a case of SAH with an initially undiscovered etiology, which was eventually discovered to be ruptured anterior communicating artery (AComA) aneurysm after reevaluation following rebleeding. Endovascular approach was successfully delivered in the acute phase.

Results: A 35-year-old male presented with a sudden onset of severe headache for three hours, accompanied with vomiting and loss of consciousness. Brain CT revealed diffuse SAH predominantly located in the anterior interhemispheric fissure (Hunt and Hess 3, World Federation of Neurosurgical Societies (WFNS) 2, modified Fisher 3). Initial diagnostic work-up with brain CTA and DSA revealed no significant findings. He was managed with lumbar drain for cerebrospinal fluid diversion and admitted to intensive care unit for close monitoring of potential complications. On the fifth day of admission, he experienced a second thunderclap headache. Follow-up CT revealed worsening of SAH. Repeated DSA revealed a small blister like aneurysm 1.6mmx1.6mm at AComA. Emergent endovascular treatment using 2.25mmx- 15mm Silk Vista Baby (Balt, Montmorency, France) and adjunctive Target 1x3mm 360 soft coils (Stryker, Michigan, USA) was successfully carried out, result- ing in complete obliteration of the aneurysm (Raymond-Roy Grade 0). He received double antiplatelet thereafter. His condition gradually improved over subsequent days and was discharged without neurological sequelae.

Conclusion: Re-evaluation of SAH etiology is essential, especially in cases of deterioration. Prompt endovascular treatment using FD and coiling is safe and effective during the acute phase.

A-012

The Real-World Practice Outcomes of Bridge Mechanical Thrombectomy in the Northern Taiwan

Category: Acute Ischemic Stroke

Primary Author

Yao Liang Chen

Department of Radiology, Chang Gung Memorial Hospital, Keelung, Taiwan

Co-Author

Wen-Chun Deng

Department of Neurosurgery, Chang Gung Memorial Hospital, Keelung, Taiwan

Yi-Ming Wu

Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan

Ching-Chang Chen

Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, Chang Gung University, Taoyuan, Taiwan

Chien-Hung Chang

Department of Neurology, Chang Gung Memorial Hospital and Chang Gung University, Linkou, Taoyuan, Taiwan

Ho-Fai Wong

Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou ,Taoyuan, Taiwan

Background and Purpose: Bridge mechanical thrombectomy (BMT) plays an essential role in treatment of large vessel occlusion (LVO) of patients with acute ischemic stroke failed to response to intravenous thrombolysis, either within or extended time windows. The study aimed to present real-world results of BMT with different dosages of tissue plasminogen activator (TPA), either in the standard or extended time windows in an independent referral system in the northern Taiwan.

Materials and Methods: In total, 576 patients with acute anterior circulation ischemic stroke treated with mechanical thrombectomy (MT) between 2017 and 2021 at an independent referral system, composed of two allied stroke centers, were retrospectively reviewed. Of all patients underwent MT, BMT and TPA were performed for 423 patients, which were categorized as full (0.9 mg/ kg) or reduced (<0.9 mg/kg) dose. Standard time window (STW) cohort was defined as BMT or MT performed within six hours (6Hs) of acute ischemic stroke onset, while those underwent BMT beyond 6Hs as the extended time window (ETW) cohort. 90 days Modified Rankin Scale (mRS) score, technical treatment success, in-hospital mortality, and post- treatment hemorrhage were analyzed.

Results: Within the STW cohort, the BMT group showed higher rates of good functional outcomes (GFO) at 90 days (mRS 0-3) than the non-bridge group, (25% vs 12%, p= 0.049). In those 423 patients with BMT, 218 of which treated in the STW, while 205 treated in the ETW. Within the STW, the full-dose TPA group demonstrated a higher proportion of GFO at 90 days (mRS0-3) versus reduced (49% vs 21%, p = 0.0358). The overall GFO of STW was higher than that of the ETW (33% vs 20%, p = 0.0480). Within the ETW, GFO was similar between full and reduced dose groups. Successful reperfusion rate was lower in STW versus ETW cohorts (39% vs 58%, p = 0.0199). There were no statistic differences of excellent functional outcome at 90 days (mRS 0-2) within all categories.

Conclusion: In real-world practice, the GFO of BMT is better than MT alone. The TPA dosage is not a determining factor of GFO in ETW BMT.

A-013

Case Report: Endovascular management of a big aneurysm at vertebrobasilar fenestration with Flow diverter

Category: Cerebral Aneurysm

Primary Author

Wei Liang Chen

CMUH/Medical Imaging Taiwan

Co-Author

Wei Liang Chen

Neuroradiology

Ying-Lin Tseng

Neuroradiology

Jeng-Hung Guo

Neuroradiology

H-F Wong

Neuroradiology

Background and Purpose: We report a case of a big aneurysm at fenestration of vertebrobasilar junction, which was successful treated with a flow diverter and parent artery occlusion of one vertebral artery.

Materials and Methods: A 57 years-old female has the history of hypertension under medication. She suffered headache and dizziness for years, more exacerbation recently weeks. MRI and DSA showed an 11.5x12.5mm big aneurysm at a fenestration of vertebrobasilar junction. A Pipeline Shield Embolization Device (4.5x15mm) was deployed from right VA to BA. And then parent artery occlusion of left distal VA with 8 coils were performed. The postprocedural angiogram showed delayed arterial flow into aneurysm and patency of vertebrobasilar arteries.

Results: She felt headache for 3 days after treatment. Then she was discharged with improved headache and normal neurologic condition. The headache was completely improved after 1 month. The 3 months follow up MRI showed subacute thrombosis of the aneurysm. The 6 months follow up DSA showed total occlusion of the aneurysm with patency of vertebrobasilar artery.

Conclusion: Develpment of aneurysm at anatomic variant of fenestration is rare. Endovascular management with coiling of a big posterior fossa may increase mass effect to brainstem. We report an effective and successful endovascular treatment with flow diverter and parent arterial occlusion for this rare aneurysm.

A-014

Super-selective embolization of vasa vasorum within partially thrombosed vertebral aneurysm

Category: Cerebral Aneurysm

Primary Author

Takashi Izumi

Department of Neurosurgery, Nagoya University Japan

Co-Author

Masahiro Nishihori

Department of Neurosurgery, Nagoya University

Shunsaku Goto

Department of Neurosurgery, Nagoya University

Issei Takeuchi

Department of Neurosurgery, Nagoya University

Takumi Otake

Department of Neurosurgery, Nagoya University

Ryuta Saito

Department of Neurosurgery, Nagoya University

Background and Purpose: Partially thrombosed vertebral artery aneurysms (PTVAs) are rare, most of which are not easy to treat. Furthermore, endovascular treatment of PTVAs may not have favorable outcomes. The relationship between PTVAs and well-developed vasa vasorum (VV), including the mechanism of aneurysm growth, has been reported, but there are no reports of imaging findings by digital subtraction angiography (DSA). In this case, we successfully performed superselective angiography of well-developed VV and evaluated its imaging characteristics. We present the first DSA report of a well-developed VV of PTVA.

Materials and Methods: A 54-year-old patient presented with a PTVA that exerted a mass effect on the medulla oblongata. The aneurysm had no cavity due to thrombosis. The 3-dimensional DSA images indicated V V. Superselective angiography of the VV indicated staining of the thrombosed aneurysm and draining into the suboccipital cavernous sinus through the venous VV.

Results: VV embolization with n-butyl cyanoacrylate was performed. After 3 months, the contrast effect of the aneurysm on contrast-enhanced magnetic resonance imaging disappeared and aneurysm shrinkage was observed. After 18 months, the reduction in aneurysm size was maintained.

Conclusion: We successfully identified a VV within PTVA. Superselective VV angiography showed staining of the thrombosed component and venous return draining into the suboccipital cavernous sinus. In this case, the embolization of the VV proved to be an effective endovascular treatment of PTVA, but the safety of this method is a challenge. Further case studies are required to validate this method, and we hope it will evolve into a new treatment of PTVA.

A-015

Long-Term Outcomes of Ruptured Blood Blister-Like Aneurysms with Multiple (2)Overlapping Stents and Coiling: A Single-Center Experience

Category: Cerebral Aneurysm

Primary Author

Jihye Song

Ajou University School of Medicine South Korea

Co-Author

Yong Cheol Lim

Ajou University School of Medicine

Background and Purpose: To evaluate the long-term feasibility ofmultiple overlapping stents (‡2) with or without coiling fortreating blood blister-like aneurysms (BBAs)

Materials and Methods: BBAs treated with stent-assisted coiling orstent-only therapy wasincluded. BBAs with atypicalanatomical locations, other endovascular or surgicaltechniques performed, and delayed treatment (>48 hours)were excluded. Medical records of patients and proced-ures were retrospectively reviewed

Results: Seventeen patients with BBAs were identi-fied, and 15 were treated with stent-assisted coiling and 2 with stent-only therapy. Triple overlapping stents wereperformed in seven patients, double stents in nine, and asingle stent with coiling in 1. One patient experienced in-stent fibrin formation and received intra-arterial tirofiban.Complementary treatment was required in four patients.Three patients were initially treated with double (3/9) and 1with triple stents (1/7). Three recurred in the acute period(£6 weeks) and 1 recurred 14 months after treatment. Threeof 17 patients with Hunt Hess grade 5 died early. Thirteenpatients were available for long-term angiographic follow-up (13.8 8.9 months). Final angiography showed completeaneurysm occlusion in all patients without in-stent steno-sis or perforating vessel occlusion. Clinical follow-up datawere available for all 14 surviving patients (66.8 40.9 months). Eight patients had favorable out-comes, five had unfavorable outcomes, and 1 died of subarachnoid hemorrhage-unrelated cause. Delayedinfarct or hemorrhage was not documented.

Conclusion: Even in the era of flow diverter stents,the use of multiple overlapping stents with or withoutcoiling can be a feasible alternative for treating rupturedBBAs.

A-016

Depression or Anxiety According to ManagementModalities in Patients With UnrupturedIntracranial Aneurysms

Category: Cerebral Aneurysm

Primary Author

Jihye Song

Ajou University South Korea

Co-Author

-

Background and Purpose: In the treatment of unruptured intracranial aneurysms, the risk was usually estimated by objective neurologicalsequelae. However, their effects on depression and anxiety are rare and remain controversial. We aimed to evaluate therisk of depression and anxiety in patients with unruptured intracranial aneurysm stratified by management strategies in apopulation-based, longitudinal cohort study.

Materials and Methods: Using the Korean National Health Insurance Research Database, 71 750 patients with unruptured intracranialaneurysms between 2008 and 2011 were identified and followed up until the end of 2020. The risk of depression andanxiety was compared among management strategies with respect to age, sex, and medical comorbiditie

Results: The Kaplan-Meier survival curves indicated that the treatment (clipping and endovascular treatment) group developeddepression more frequently than the observation group (P<0.001). The adjusted hazard ratio was 1.11 (95% CI, 1.07–1.15)in the treatment group. According to the management modality, the Kaplan-Meier survival curves indicated that clipping andendovascular treatment groups developed depression more frequently than the observation group (P<0.0001). The adjustedhazard ratio was 1.15 (95% CI, 1.10–1.21) for clipping and 1.07 (95% CI, 1.02–1.12) for endovascular treatment. Thedepression risk was higher with advanced age (hazard ratio for 45–64 years, 1.37 [95% CI, 1.29–1.45] and hazard ratio for≥65 years, 2.04 [95% CI, 1.92–2.17]). The risk for anxiety did not differ among the management modalities.

Conclusion: In this study, the risk of depression was slightly greater after clipping surgery than endovascular treatment.Data on treatment-related, long-term psychological outcomes, such as depression, may aid decision-making for preventivetreatment of asymptomatic unruptured intracranial aneurysm patients

A-017

A Case of Spinal Intraosseous Epidural Arteriovenous Fistula

Category: Spinal vascular diseases

Primary Author

Issei Takeuchi

Department of Neurosurgery, Nagoya University Graduate School of Medicine Japan

Co-Author

Takashi Izumi

Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan

Masahiro Nishihori

Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan

Shunsaku Goto

Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan

Shinsuke Muraoka

Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan

Ryuta Saito

Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan

Background and Purpose: Spinal intraosseous epidural arteriovenous fistula is an extremely rare vascular anomaly. Although trauma and surgical intervention have been suggested as possible causes, its precise pathogenesis remains unclear. We report a rare case of spinal intraosseous epidural AVF associated with vertebral compression fracture.

Materials and Methods: A 55-year-old man presented with sudden-onset low back pain without any history of trauma. He was initially diagnosed with an L3 compression fracture and underwent balloon kyphoplasty (BKP) and biopsy. A few months later, he developed gait disturbance. MRI revealed flow voids, and massive bleeding occurred during a second biopsy. CTA suggested a shunt disease, and he was referred to our institution.

Results: Digital subtraction angiography demonstrated multiple feeders arising from bilateral L2–L4 segmental arteries, converging into a cavity within the L3 vertebral body and draining into the internal vertebral venous plexus. Via the azygos arch, trans- venous embolization using Onyx was performed, resulting in significant reduction of venous congestion. Postoperative MRI showed improvement in spinal cord

Conclusion: This case provides valuable insight into the diagnostic and therapeutic approach to the exceptionally rare entity of spinal intraosseous epidural AVF. In recent years, transvenous embolization in the spinal region has been reported for cerebrospinal fluid leakage. These advancements suggest that a deeper understanding of spinal venous anatomy may become increasingly essential for managing shunt-related spinal pathologies.

A-019

Pediatric neurointerventions: A potpourri of 128 juvenile patients

Category: Pediatric Vascular diseases

Primary Author

Saima Ahmad

Pakistan

Co-Author

-

Background and Purpose: The subspeciality of paediatric neurointerventional radiology is developing due to new advances in technology, including smaller devices and lower radiation doses, as well as expanding indications. Our understanding of these conditions, their pathogenesis and natural history has improved in recent years. The necessity of doing these treatments, considering the inherent greater risks of radiation and cerebrovascular impairment in infants, is constantly weighed against the ability to do so. Furthermore, since cardiovascular comorbidities linked to cerebrovascular illness are not typically present at this age, children may have etiologies that are more complex. This study aims to clarify trends in this patient population by reviewing the neurointerventional experience our institution has had with pediatric population.

Materials and Methods: In order to share our insights gained from a decade of experience, we report on the paediatric neurointervention cohort from our centre. Our neuroendovascular database underwent a retrospective assessment. All patients who had neurointerventions between the ages of two months and twenty-one were included. Treatment type, indication, and location as well as patient demographics were extracted from the medical record.

Results: The study included 128 patients, 28 of whom had aneurysms, 50 of whom had arteriovenous malformations, arteriovenous fistulas, and Vein of Galen aneurysmal malformations, 31 of whom displayed tumours such as angiofibroma, haemangioma, and giant cell tumour, and 21 who had stenosis, dissections, and cerebral proliferative angiopathies. The overall mortality rate was 3.1%, with 85.9% of patients reporting no complications following the treatment. Tables 1–4 provide information about disease treatment, location, and outcomes.

Conclusion: The role of endovascular therapy in the management of children with cerebrovascular diseases is rapidly evolving, and experience with new endovascular devices and embolic materials is just gaining momentum. It is anticipated that in the future the role of endovascular therapy will continue to grow as part of the multidisciplinary team approach to the management of children presenting with complex vascular diseases of the central nervous system.

A-020

Delayed symptomatic thrombembolism after coil embolization of Unruptured basilar artery top aneurysm: A case report

Category: Cerebral Aneurysm

Primary Author

T Gong

Presbyterian medical center,Department of neurosurgery South Korea

Co-Author

-

Background and Purpose: Endovascular treatment has been increasingly performed for unruptured intra cerebral aneurysms. However, thromboembolic complications, which develop mostly within 48 hours after the procedure, are the most common and major complications of endovascular treatment. We present a rare case of delayed symptomatic thromboembolism in an ischemic stroke patient who had under gone coil embolization for unruptured basilar artery top aneurysm.

Materials and Methods: We report a case of 68 year old man coil embolization for unruputured basilar artery top aneurysm The patient visited our hospital complaining of chronic headache. The patient was diagnosed with unruptured basilar arery top wide neck Aneurysm(3.70x3.75x3.84mm) on conventional angiography..Endovascular coiling was done and final angiography showed complete obliteration of aneurysm, The patient full wake up without any neurological symptoms.

Results: 7 days after coil embolization,The patient was found to be unconscious and had left arm and leg weakness. Emergency cerebrovascular angiography showed a occlusion of the basilar artery, and after the emergency mechanical thrombolysis,recanalization of occluded artery was done.The patient is fully recovered and has no neurological sequelae.

Conclusion: Most thromboembolic complications occur within 48 hours of endovascular treatment; therefore, antiplatelet or anticoagulant is used during the procedure. However, delayed thromboembolic event beyond 2 days after coil embolization may occur despite its rarity. Here, we present a case of delayed symptomatic thromboembolism which occurred 7 days after the coil embolization of an unruptured aneurysm despite antiplatelet therapy.

A-021

Microsurgical Disconnection of C1 Nerve Root DAVFs at the Craniocervical Junction: Treatment Principles and Technical Insights from Eight Cases

Category: Spinal vascular diseases

Primary Author

Sitthisak Phupungtamakoon

Department of Neurosurgery, Samut Sakhon Hospital, Samut Sakhon, Thailand, Thailand

Co-Author

Prasert Iampreechakul

Department of Neurosurgery, Neurological Institute of Thailand, Bangkok, Thailand

Background and Purpose: Dural arteriovenous fistulas (DAVFs) at the craniocervical junction (CCJ) involving the C1 spinal nerve root are rare but surgically curable vascular lesions. Their deep location, complex anatomy, and small-caliber feeders present diagnostic and therapeutic challenges. We report treatment principles and technical outcomes from eight cases, including one with holocord myelopathy.

Materials and Methods: Eight patients with CCJ DAVFs at the C1 level were retrospectively reviewed. All underwent 3T MRI, contrast-enhanced MRA, rotational CTA, and digital subtraction angiography. Seven patients were treated with microsurgical disconnection via lateral suboccipital craniotomy and ipsilateral C1 hemilaminectomy; one underwent endovascular embolization.

Results: Among eight patients (5 men, 3 women; median age 54, range 48–72), five (71.4%) presented with subarachnoid hemorrhage (SAH) and three (28.6%) with progressive myelopathy. All fistulas except one were supplied by the radiculomeningeal branch of the vertebral artery at the C1 level. Venous aneurysms were present in all SAH cases and were the presumed source of bleeding. Microsurgical procedures were performed in lateral decubitus position. After dural opening, the denticulate ligament and dorsal root of the C1 nerve were exposed. The arterialized draining vein was identified using intraoperative indocyanine green angiography and confirmed by color change after disconnection. Clipping or coagulation of the intradural draining vein was the key therapeutic step. One patient required reoperation after failed extradural feeder coagulation. All surgically treated patients achieved complete angiographic obliteration within one week. Most had favorable neurological outcomes; two experienced transient trapezius muscle spasm. One patient treated endovascularly had treatment failure and died from sepsis and gastrointestinal bleeding. In the illustrative myelopathy case, the patient regained ambulation and experienced near-complete resolution of bowel and bladder dysfunction by six months.

Conclusion: Microsurgical disconnection of the intradural draining vein offers definitive and durable treatment for C1-level CCJ DAVFs. In anatomically complex cases, surgery provides superior control compared to endovascular approaches. This series reinforces the value of consistent, anatomy-guided microsurgical technique in achieving high cure rates with low morbidity.

A-022

Quantitative index of cerebral aneurysm projection and parent artery curvature in flow diverter placement

Category: Cerebral Aneurysm

Primary Author

Hideki Kanamaru

Mie university Japan

Co-Author

Naoki Toma

Mie university

Yume Suzuki

Mie university

Yoshinari Nakatsuka

Mie university

Ryuta Yasuda

Mie university

Hidenori Suzuki

Mie university

Background and Purpose: In cerebral aneurysm treatment using flow diverters (FDs), the curvature of the parent artery and the projection of the aneurysm may influence procedural complexity and occlusion status. However, standardized quantitative measures for these anatomical features are lacking. This study aimed to develop and validate a method for objectively assessing these factors using a cerebral angiography system workstation.

Materials and Methods: We retrospectively analyzed preoperative three- dimensional rotational angiography images from patients treated with FDs for unruptured internal carotid artery aneurysms between 2017 and 2022. Using SmartCT (Philips), a centerline was generated along the parent artery. Point N was defined at the aneurysm neck, with points P and D located 10 mm proximal and distal to N, respectively on the centerline of the parent artery. The aneurysm tip (T) was identified as the furthest point from N on the aneurysm’s outline. Two indices were calculated: the curvature ratio (C ratio)—defined as 20 mm divided by the 3D lin- ear distance PD, representing vessel tortuosity; and the projection angle (P angle)—the angle TNP (in the plane where point P and point D coincide), quantifying aneurysm projection. Aneurysm occlusion was evaluated at 6 months post-treatment via angiography, with O’Kelly–Marotta grades C and D considered good occlusion.

Results: Thirty-six cases were included (mean age 65.9 years; mean dome diameter 13.5 mm; mean neck diameter 8.1 mm). The P angle was significantly lower in cases with good occlusion versus poor occlusion (81.8° vs. 145.7°, p<0.01). Receiver operating characteristic analysis yielded an area under the curve of 0.90, with an optimal P angle cutoff of 96.1°. Multi- variate analysis identified P angle as an independent predictor of good occlusion (odds ratio 0.95; 95% CI 0.91–0.99; p=0.03). The C ratio was not significantly associated with occlusion but negatively correlated with neck diameter (r = –0.46; p<0.01).

Conclusion: This method allows quantitative evaluation of parent artery tortuosity and aneurysm projection. The P angle, in particular, may serve as a valuable predictor of aneurysm occlusion following FD placement.

A-024

Intracerebroventricular SRPX2 Administration Attenuates Neurological Deficits and Cerebral Vasospasm in a Mouse Model of Subarachnoid Hemorrhage: A Pilot Study

Category: Cerebral Aneurysm

Primary Author

Yushin Takemoto

Japanese Red Cross Kumamoto Hospital Japan

Co-Author

Kozo Tashima

Department of Neurosurgery, Kumamoto University Hospital

Yuki Nakagaki

Department of Neurosurgery, Kumamoto University Hospital

Hiroki Uchikawa

Department of Neurosurgery, Kumamoto University Hospital

Yasuyuki Kaku

Department of Neurosurgery, Kumamoto University Hospital

Akitake Mukasa

Department of Neurosurgery, Kumamoto University Hospital

Background and Purpose: Hypothalamic dysfunction following subarachnoid hemorrhage (SAH) has been reported to correlate with poor outcomes, yet no therapies directly target the hypothalamus. Sushi repeat–containing protein X-linked 2 (SRPX2), a hypothalamic protein, has recently been implicated in neuroprotection, tissue repair, and autonomic regulation after brain injury. We previously demonstrated an acute decrease in SRPX2 levels in moderate-to-severe SAH model rats. Here, we hypothesized that SRPX2 administration would attenuate neurological deficits and cerebral vasospasm after SAH.

Materials and Methods: Male C57BL/6N mice (28.6–34.7 g) were randomly assigned to three groups (n=5 each): Sham + PBS, SAH + PBS, and SAH + SRPX2. Twenty-four hours before induction of SAH via endovascular perforation (or sham surgery), mice received intracerebroventricular injections of SRPX2 (dose 0.24μg) or PBS. At 24 h post-SAH, we evaluated neurological function (Garcia score, beam balance test), early brain injury (brain water content, BWC), and delayed cerebral ischemia (basilar artery diameter). Immunohistochemistry assessed activation of PI3K/AKT and uPAR-FAK-ERK signaling pathways.

Results: SAH + PBS mice developed significant hypertension, worsened neurological scores, and basilar artery wall thickening compared to Sham + PBS. SRPX2 treatment significantly attenuated the SAH-induced rise in mean arterial pressure (p = 0.03), restored Garcia scores to sham levels, and improved beam balance performance (p = 0.03). No differences in BWC were observed among the groups. However, SRPX2 markedly reduced basilar artery wall thickness versus SAH + PBS (p = 0.01). Immunohistochemical analysis revealed that while pAkt expression did not differ between groups, SRPX2 suppressed the SAH-induced upregulation of pERK (p = 0.001), suggesting inhibition of FAK-ERK signaling.

Conclusion: Intracerebroventricular SRPX2 administration prior to SAH ameliorates neurological deficits and cerebral vasospasm in this pilot study. The data indicate a potential influence of SRPX2 on hypothalamic and vascular function via the uPAR-FAK-ERK pathway. Further studies with larger sample sizes and detailed mechanistic exploration are warranted to validate SRPX2 as a novel therapeutic target in SAH.

Disclose all financial interests: This research was supported by the Japan Society for the Promotion of Science through a Grant-in-Aid for Scientific Research (KAKENHI) (Grant Number 23K15671) awarded to Yushin Takemoto.

A-025

Endovascular strategy for intraosseous AVFs near the hypoglossal canal without embolizing the anterior condylar vein

Category: Dural Arteriovenous Fistulae

Primary Author

Naoki Toma

Mie University Hospital Japan

Co-Author

Fuki Goto

Mie University Hospital

Yume Suzuki

Mie University Hospital

Hideki Kanamaru

Mie University Hospital

Ryuta Yasuda

Mie University Hospital

Hidenori Suzuki

Mie University Hospital

Background and Purpose: Intraosseous arteriovenous fistulas (AVFs) near the hypoglossal canal often drain into the anterior condylar vein (ACV), posing risks of hypoglossal nerve palsy if embolized. This anatomy presents distinct diagnostic and therapeutic challenges.

Materials and Methods: We analyzed 10 patients with intraosseous AVFs adjacent to the hypoglossal canal who underwent endovascular treatment between 2014 and 2025. Angioarchitecture was assessed using MRI, CTA/ CTV, and 3D rotational angiography. Shunted pouch locations were classified into four directions superior (S), inferior (I), lateral (L), and posterior (P) based on anatomical landmarks: S corresponded to the jugular tubercle, I to the occipital condyle, L to the condylar fossa, and P to the margin of the foramen magnum.

Results: Mean age was 71.8 years; seven were female. All presented with pulsatile tinnitus; two also exhibited ocular symptoms, one had hypoglossal palsy. Nine cases were Borden type I, one type II. Shunted pouches were located at a single site in six patients, at two sites in three, and at four sites in one. The directional distribution of shunted pouches was S (n=7), P (n=5), L (n=3), and I (n=1). Venous drainage involved the internal jugular vein via the anterior condylar confluence (ACC) in nine cases; additional routes included the inferior petrosal sinus (n=3), lateral condylar vein (n=4), posterior condylar vein (n=3), and marginal sinus (n=2). All patients underwent transvenous coil embolization. In three cases, adjunctive transarterial coil embolization was performed, and in two cases, transvenous injection of n-butyl cyanoacrylate was additionally employed. One case required access via the vertebral venous plexus, with embolization of the shunted pouch and the inferior petrosal sinus to prevent cortical reflux. Seven achieved immediate complete or near-complete occlusion; three required retreatment. Post-treatment CT confirmed that coils were confined to the shunted pouch, avoiding the hypoglossal canal. No new neurological deficits occurred. All patients showed improvement.

Conclusion: Careful evaluation of venous anatomy enables safe and effective endovascular treatment of intraosseous AVFs near the hypoglossal canal. Targeted embolization at the shunted pouch while preserving the ACV and recognizing the ACC as an outflow channel is key to preventing nerve injury.

A-028

Effectiveness of Continuous Intra-arterial Nimodipine Infusion for the Treatment of Refractory Vasospasm after Aneurysmal Subarachnoid Hemorrhage

Category: Cerebral Aneurysm

Primary Author

Yeongu Chung

Kangbuk Samsung Hospital, Sungkyunkwan University South Korea

Co-Author

Hyunbong Lee

Kangbuk Samsung Hospital, Sungkyunkwan University

Youngbo Sim

Kangbuk Samsung Hospital, Sungkyunkwan University

Background and Purpose: Delayed cerebral ischemia (DCI) is a severe complication following aneurysmal subarachnoid hemorrhage (aSAH), potentially leading to functional impairments. Cerebral vasospasm (CVS) is one of the primary mechanisms of DCI. In cases of medically refractory CVS, intra-arterial (IA) nimodipine is a rescue treatment, but its effectiveness can be insufficient. We hypothesized that continuous IA nimodipine infusion (CIAN) could serve as a salvage treatment, and we evaluated its effectiveness and safety.

Materials and Methods: We evaluated 274 patients with aSAH admitted between October 2017 and February 2024, identifying those who received IA nimodipine and those who also received CIAN. The modified Rankin Scale (mRS) score at discharge was assessed in the CIAN group, and patient and disease characteristics, length of stay, and discharge mRS scores were compared between the conventional IA nimodipine and the CIAN groups.

Results: Of the 274 patients, 15 received IA nimodipine, and five of those underwent CIAN. More females were observed in the medically refractory CVS group compared with the non-refractory group (87% [13/15] vs. 66% [171/259]), but there was no sex difference between the CIAN and conventional IA nimodipine groups. CIAN was initiated at a mean of 9 days after the onset of aSAH and continued for 21–81 hours. Two complications were noted, including severe brain edema and suspected heparin-induced thrombocy- topenia. However, radiological assessments showed no new lesions. The CIAN group exhibited a longer duration of abnormal findings on transcranial Doppler compared to the conventional IA group (16.0±10.1 vs. 9.4±7.9 days), as well as longer NCU (17.4±10.1 vs. 14.1±7.0 days) and hospital stays (46.6±28.7 vs. 29.5±14.1 days). Nonetheless, more achieved a favorable outcome (mRS≤2) in the CIAN group (80% [4/5] vs. 70% [7/10]).

Conclusion: CIAN is a viable salvage treatment for refractory CVS, providing a prolonged vasodilatory effect compared to conventional IA nimodipine, with favorable outcomes.

A-029

Mechanical Thrombectomy for Large Vessel Occlusion Involving an Unrecognized Aneurysm with Hyperdense Sign on CT: A Case Report

Category: Acute Ischemic Stroke

Primary Author

Ryosuke Kaneko

Sunrise Japan Hospital Cambodia

Co-Author

Hiroyuki Ikeda

Kyoto University Hospital

Masaki Chin

Kurashiki Central Hospital

Background and Purpose: We report a case of acute ischemic stroke in an elderly male with a known unruptured right internal carotid–posterior communicating artery (IC-PC) aneurysm identified on MRA four years prior. He was found with left hemiparesis 90 minutes after last known well while hospitalized for rehabilitation. MRI showed a DWI-ASPECTS of 4 in the right MCA territory, and MRA revealed right ICA occlusion. Due to low ASPECTS, IV thrombolysis was not administered, and the patient was transferred for mechanical thrombectomy (MT).

Materials and Methods: On admission, NIHSS was 17. Head CT revealed a hyperdense sign from the right ICA C2 to the M1 segment, coinciding with the location of the known IC-PC aneurysm, although this was not recognized at the time of treatment initiation. MT was performed under local anesthesia via a right femoral approach using a Solitaire X stent retriever and React 71 aspiration catheter. During the procedure, the aneurysm was visualized on angiography. To minimize mechanical stress, the aspiration catheter was not advanced beyond the thrombus, and the retriever and microcatheter were carefully withdrawn under aspiration. Complete recanalization was achieved without aneurysmal rupture.

Results: This case illustrates that a hyperdense sign on preoperative CT may reflect not only thrombus but also flow stagnation within an aneurysm adjacent to an occlusion. The aneurysm’s visibility on post-deployment angiography despite prior occlusion suggests that proximal thrombus-induced stagnation may have led to hyperdensity on CT. Although not previously reported as a mechanism, this phenomenon may offer a new diagnostic clue to identifying aneurysms hidden by acute occlusions.Furthermore, the use of axial and sagittal CT views was critical in retrospect for detecting the hyperdense aneurysm. This case emphasizes the need for thorough review of preoperative imaging and consideration of past vascular studies when planning MT. When aneurysms are suspected or identified intraoperatively, techniques that minimize stress such as the ADAPT or combined approach should be considered to ensure procedural safety.

Conclusion: To our knowledge, this is the first reported case of MT in an occluded vessel involving a hyperdense aneurysm, with implications for improving preoperative detection and intraoperative strategy.

A-031

Single Neuroform Atlas stent: a reliable approach for treating complex wide-neck bifurcated aneurysms

Category: Cerebral Aneurysm

Primary Author

Hong Jun Jeon

Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, South Korea

Co-Author

Hong Suk Ahn

Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine

Byung Moon Cho

Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine

Se Hyuck Park

Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine

Background and Purpose: Treating wide-neck bifurcated cerebral aneurysms (WNBAs) using various techniques and new devices has shown favorable outcomes. However, endovascular coiling can be technically challenging when the aneurysm neck is incorporated into the parent vessel. Furthermore, although recent research has reported favorable outcomes of Neuroform Atlas stent (NAS)-assist-ed coiling, broad inclusion criteria have hampered precise evaluations of their effectiveness and safety for treating complex WNBAs. Therefore, this study evaluated whether the use of a single NAS is a safe and effective approach for treating complex WNBAs.

Materials and Methods: We treated 76 complex WNBAs (unruptured, n = 49; ruptured, n = 27) using single NAS-assisted coil embolization and retrospectively analyzed the clinical and angiographic outcomes.

Results: In a cohort of 68 patients (mean age, 58.3 ± 11.6 years; males n = 20, 29.4%; females, n = 48, 70.6%), 76 stents were successfully delivered to the target aneurysms, yielding a technical success rate of 98.6%. Complete occlusion was evident in 59 (77.6%) of 76 aneurysms, with neck remnants found in 16 (21.1%) and partial occlusion in 1 (1.3%). Treatment-related morbidities comprised one branch occlusion and one parenchymal hemorrhage. However, no new neurological symptoms of unruptured aneurysms were evident at discharge. The outcomes of 20 of the 27 ruptured aneurysms were favorable (Glasgow Outcome Scale scores of 4 or 5) at the final follow-up assessment (mean 12.2 [6–29] months), except for one initial subarachnoid hemorrhage. Posttreatment angiography revealed complete occlusion in 89.1%, neck remnants in 7.8%, and incomplete occlusion in 3.1% of the aneurysms. Approximately 88.2% of the patients were assessed at least once by follow-up diagnostic or magnetic resonance angiography (mean, 12.5 ± 4.3 [range, 6–29] months), with five (7.8%) minor and two (3.1%) major recurrences.

Conclusion: A single NAS is safe and effective for treating WNBAs incorporated into parent vessels.

A-032

Thrombectomy with Carotid Stent Thrombus Trapping in Acute Tandem Occlusion of Cervical ICA and MCA

Category: Acute Ischemic Stroke

Primary Author

Chiu Shih Cheng

E Da Hospital, Taiwan Taiwan

Co-Author

Wan-Ching Lin

E Da Hospital, Taiwan

Chang-Hsien Ou

E Da Hospital. Taiwan

Background and Purpose: Carotid free-floating thrombus (FFT) with distal embolization to the middle cerebral artery (MCA) represents a rare and challenging condition in the context of acute ischemic stroke (AIS). Traditional mechanical thrombectomy techniques such as aspiration and stent retrievers are often less effective in cases where the thrombus is large, elastic, and prone to fragmentation, which increases the risk of distal embolization. Despite advancements in endovascular therapy, optimal management strategies for tandem occlusions involving carotid FFT and MCA embolic occlusion remain unclear. We introduce a technique combining carotid stent placement for thrombus trapping followed by MCA thrombectomy, offering a potential solution for these complex cases. We detail the steps of the procedure and discuss important considerations to prevent thrombus migration.

Materials and Methods: We present the case of a 51-year-old male with history of hypertension who presented with acute right-sided weakness and NIHSS score of 13. CT angiography (CTA) and CT perfusion (CTP), revealed a free-floating thrombus in the left cervical internal carotid artery (ICA) and occlusion of the left M1 segment of the MCA. Carotid stent was deployed to trap the free-floating thrombus against the vessel wall, followed by mechanical thrombectomy of the MCA using contact aspiration. Balloon-guide catheter and embolic protection device (Spider FX) were used to minimize distal thrombus migration.

Results: Post-procedural imaging demonstrated partial recanalization of the left MCA M3 branches with a TICI 2c reperfusion. Complete recanalization of the left cervical ICA was achieved, with the thrombus successfully trapped outside the stent. Clinically, the patient showed significant improvement, with a modified Rankin Scale (mRS) score of 1 at discharge.

Conclusion: Thrombectomy combined with carotid stent thrombus trapping offers a safe, and effective strategy for treating AIS due to carotid FFT with tandem occlusion of the cervical ICA and MCA. This technique ensures thrombus containment and maintains ICA patency. Key procedural considerations include stent selec- tion, and post-procedural antiplatelet therapy.

A-033

Paraspinal Arteriovenous Shunts: Four Cases from a Single Center

Category: Spinal vascular diseases

Primary Author

Katsuhiro Mizutani

Keio University, School of Medicine Japan

Co-Author

Kosuke Karatsu

Keio University, School of Medicine

Tsubasa Miyauchi

Keio University, School of Medicine

Masahiro Katsumata

Eiju general hospital

Takenori Akiyama

Keio University, School of Medicine

Masahiro Toda

Keio University, School of Medicine

Background and Purpose: Introduction Paraspinal arteriovenous shunt (PAVS) is a rare variant of spinal arteriovenous shunts (AVS). Traditionally, PAVS has been recognized as an AVS located outside the spinal canal in the parachordal region, highlighting the embryological origin of the vessels from which AVSs arise. However, the litera- ture reveals that PAVS encompasses a variety of etiol- ogies, including congenital, traumatic, and acquired lesions. Its pathology and etiology have not been well-organized, which complicates a thorough under- standing of this rare condition. Here, we present four cases of paraspinal AVSs from our institute and review the literature.

Materials and Methods: Case Series Our series included three acquired and one congenital PAVS (age range: 19–59 years, mean age 38.3, three males and one female). One congenital and one acquired PAVS exhibited type I angioarchitecture, while the remaining two acquired PAVSs displayed type IIIa angioarchitecture. Two acquired cases may have developed due to venous congestion or venous hypertension. Three of the cases were symptomatic and underwent transarterial embolization, resulting in complete occlusion in two cases and partial occlusion in one.

Conclusion: Discussion and Conclusion The PAVSs in our case series, as well as those in the literature, can be subdivided into three types: one with a remnant of embryological direct arterial-venous connection, one with arterial wall fragility, and one that developed secondarily due to venous congestion or venous hypertension, similar to intracranial dural AVSs. The etiology of PAVS significantly influences both its angioarchitecture and clinical manifestations, which is critical for better clinical management of this rare disease.

A-034

Treatment results of endvascular treatment for raptured aneurysms at our hospital

Category: Cerebral Aneurysm

Primary Author

Gota Nagayama

Jikei university Japan

Co-Author

Toshihiro Ishibashi

Jikei university

Naoki Kato

Jikei third hospital

Issei Kan

Jikei katsushika hpspital

Syunsuke Hataoka

Jikei university

Yuichi Murayama

Jikei university

Background and Purpose: To report the treatment outcomes of ruptured aneurysms at our hospital.

Materials and Methods: Of 350 cases of ruptured aneurysms treated at our hospital between November 2003 and December 2024, 299 cases were treated with endovascular treatment. We investigated the re-rupture rate, retreatment rate, and intraoperative rupture in these 299 cases

Results: There were no cases of re-rupture during the perioperative period, and all four cases (1.3%) of re-rupture occurred before 2008, and occurred several years after the onset of subarachnoid hemorrhage. Intraoperative rupture was significantly increased in cases using intermediate catheter.

Conclusion: Although endovascular treatment is considered to be effective in preventing re-rupture in the acute phase, some cases require long-term retreatment, and strict long-term follow-up is necessary.

A-035

Application and Convergence Study of Mechanical Engineering Concepts in Endovascular Treatment

Category: Others

Primary Author

Jung-Jae Kim

Yonsei University Severance Hospital South Korea

Co-Author

Hyun Jin Han

Yonsei University Severance Hospital

Kwang-Chun Cho

Yonsei University Yongin Severance Hospital

Keun Young Park

Yonsei University Severance Hospital

Je Hoon Oh

Hanyang University

Yong Bae Kim

Yonsei University Severance Hospital

Background and Purpose: Endovascular treatment for cerebral aneurysms is undergoing rapid evolution, driven by a better understanding of the disease and development and advancement of new devices. Given the critical role that blood flow and blood vessels play in cerebral aneurysms, it is imperative to develop a comprehensive understanding of their behavior. In this regard, mechanical engineering concepts, such as fluid dynamics and structural analysis, can be employed to elucidate the underlying mechanisms of these conditions.

Materials and Methods: The objective of this study was to apply mechanical engineering concepts to the field of endovascular treatment for cerebral aneurysms. The following specific objectives were set to achieve this aim: 1) The development of new parameters for the development, growth, and rupture of cerebral aneurysms 2) The interpretation of existing phenomena based on mechanical engineering 3) the understanding of endovascular treatment devices based on mechanical engineering.

Results: The hemodynamic parameters have been studied for rupture prediction by relating them to actual findings of cerebral aneurysms.(e.g. thin wall area of the aneurysm and hemodynamic factors) A fluid-structure interaction study has been conducted on the generation of paraclinoid aneurysms. A new concept of morphology, such as Momentum of Inertia, has been presented. We performed the measurement of mechanical properties of microcatheters, flow- diverters, and other related devices to establish a foundation for in silico analysis of these deives. For instance, mechanical engineering concepts can be applied to the prediction of microcatheter shape after steam-shaping and the interaction with aneurysm walls during WEB insertion in individual cerebral aneurysms.

Conclusion: The application of mechanical engineering concepts might improve our understanding of cerebrovascular diseases, aid in the decision-making process, and improve our understanding of current endovascular treatments and devices.

A-036

Carotid artery stenting for heavily calcified lesions after plaque modification using scoring balloon angioplasty

Category: Other Head and Neck Pathologies

Primary Author

Taichiro Imahori

Kitaharima medical center Japan

Co-Author

Shigeru Miyake

Kitaharima medical center

Ichiro Maeda

Kitaharima medical center

Hiroki Goto

Kitaharima medical center

Rikuo Nishii

Kitaharima medical center

Haruka Enami

Kitaharima medical center

Background and Purpose: Carotid artery stenting (CAS) for heavily calcified lesions (HCLs) presents technical challenges. The NSE PTA balloon (Nipro, Osaka, Japan), a scoring balloon designed for plaque modification, is commonly used in coronary and peripheral interventions. This study evaluated the feasibility and safety of using this balloon in CAS for HCLs.

Materials and Methods: We retrospectively analyzed 10 CAS procedures using the NSE PTA balloon for carotid stenosis with HCLs. Inclusion criteria were concentric calcified lesions occupying ≥270° of the vessel circumference. Efficacy outcomes included procedural success rate, stenosis improvement after NSE PTA (plaque modification prior stenting), final residual stenosis, and 6-month restenosis. Safety outcomes included 30-day major adverse events and secondary outcomes, including severe bradycardia and hypotension.

Results: The median patient age was 77 years (interquartile range: 74–83), with 90% male, and the median arc of calcification was 311° (294–334°). All 10 procedures achieved technical success. The median stenosis rate improved significantly from 86% (80–87%) pre-procedure to 67% (60–69%) post-NSE PTA (p = 0.018) and to 29% (25–37%) after stent placement (p = 0.018). No major perioperative adverse events occurred within 30 days. Secondary adverse events, such as hypotension, were transient and successfully managed. At 6 months, no significant restenosis was observed.

Conclusion: This preliminary study demonstrated that the NSE PTA balloon for plaque modification in CAS for carotid artery stenosis with HCLs achieved high technical success and favorable safety outcomes. This technique appears to be a promising and easily applicable treatment option for complex calcified lesions.

A-037

Neurointerventional Procedures Using Sheathless 8Fr Optimo Balloon Guide Catheter via Transradial Access: A Single-Center Experience with 100 Cases

Category: Cerebral Aneurysm

Primary Author

Taichiro Imahori

Kitaharima medical center Japan

Co-Author

Shigeru Miyake

Kitaharima medical center

Ichiro Maeda

Kitaharima medical center

Hiroki Goto

Kitaharima medical center

Rikuo Nishii

Kitaharima medical center

Haruka Enami

Kitaharima medical center

Background and Purpose: This study aimed to evaluate the feasibility and safety of neurointerventional procedures performed via transradial access (TRA) using a sheathless 8Fr Optimo balloon guide catheter (BGC).

Materials and Methods: We retrospectively analyzed 100 consecutive neurointerventional procedures performed via TRA using a sheathless 8Fr Optimo BGC at a single center. Technical success was defined as successful delivery of the BGC to the target vessel without conversion to an alternative access site or catheter system, along with completion of the planned procedure.

Results: A total of 100 procedures were performed in 95 patients (median age: 75 years; 63% male). The most common interventions were aneurysm coiling or flow diversion (45%) and carotid artery stenting (36%). Target vessels for BGC placement included the right carotid (59%), left carotid (31%), right vertebral (4%), and left vertebral (6%) arteries. The median BGC navigation time was 12 minutes (interquartile range: 7–20). Technical success was achieved in 95% of procedures. In five cases, conversion to transulnar, transbrachial, or transfemoral access was required; nevertheless, all planned procedures were completed successfully. Balloon inflation was utilized in 37% of procedures for distal embolic protection, rupture management, or device delivery support. No major access-related complications were observed. Symptomatic non-access-related periprocedural complications occurred in 4% of cases. The overall mortality rate was 2%.

Conclusion: Neurointerventional procedures performed via TRA using a sheathless 8Fr Optimo BGC appear to be feasible and safe, offering a high technical success rate and a low incidence of access-related complications.

A-038

Development of Multiple Dural Arteriovenous Fistulas After Treatment for Cerebral Venous Thrombosis: A Case Report

Category: Dural Arteriovenous Fistulae

Primary Author

Hansan Oh

Gachon Gil Hospital South Korea

Co-Author

-

Background and Purpose: Cerebral venous thrombosis (CVT) is a rare cause of stroke and may lead to neurological deterioration or hemorrhage. Although CVT and dural arteriovenous fistula (DAVF) are distinct entities, sinus thrombosis can cause venous hypertension and angiogenesis, resulting in DAVF formation. Development of DAVFs after CVT is rare, with reported incidences ranging from <1% to 10%. We report a case of a 63-year-old man who developed multiple DAVFs two years after CVT treatment, highlighting the need for long-term surveillance to detect delayed complications.

Materials and Methods: A 63-year-old man presented with left-hand clumsiness. He had a history of CVT diagnosed two years earlier, involving the superior sagittal, right transverse, and right sigmoid sinuses on MR venography, and was treated with warfarin (4 mg daily) for six months. On current admission, CT angiography showed ectatic cortical veins, and transfemoral cerebral angiography (TFCA) revealed multiple DAVFs involving the superior sagittal, right transverse, superior petrosal sinuses, and the torcular Herophili. A hybrid surgical approach was planned to reduce shunt volume.

Results: The patient underwent two sessions of hybrid surgery. In the first session, a posterior auricular incision and craniotomy over the right transverse–sigmoid junction were performed. Under C-arm fluoroscopy, direct punctures of the right transverse and superior petrosal sinuses were achieved, and sinus obliteration was performed using detachable and pushable coils. Craniotomy over the superior sagittal sinus allowed interruption of feeders from the occipital artery (OA) and superficial temporal artery (STA). In the second session, craniotomy over the mid-superior sagittal sinus obliterated dural AVF channels connecting the middle meningeal artery to bridging and cortical veins. A left mini-craniotomy was also performed to ligate feeders from the ethmoidal artery. Final angiography revealed residual Cognard type IV shunt via the occipital artery and type IIA shunt at the torcular Herophili. Despite residual shunts, the patient’s neurological symptoms improved, and he was discharged with a modified Rankin Scale (mRS) score of 0.

Conclusion: DAVFs can develop as delayed complications after CVT, underscoring the importance of long-term surveillance. A combined surgical-endovascular approach effectively reduced shunt burden and achieved favorable neurological recovery.

A-039

Hybrid Treatment for Dural Arteriovenous Fistula of the Posterior Condylar Vein: A Transtubercle Combined Transradial Approach

Category: Dural Arteriovenous Fistulae

Primary Author

Jirapong Vongsfak

คณะแพทยศาสตร์ มหาวิทยาลัยเชียงใหม่ Thailand

Co-Author

Withawat Vuthiwong

Supachart Chaewchantuek

Chanon Srihagulang

Kittisak Unsrisong

Wanarak Watcharasaksilp

Background and Purpose: Dural arteriovenous fistulas (DAVFs) involving the posterior condylar vein at the skull base are exceedingly rare, and their complex anatomy presents significant treatment challenges. Endovascular therapy is typically the preferred treatment approach. We report a hybrid treatment case involving surgical disconnection of the fistula via a transtubercle approach, combined with intraoperative angiography through a transradial approach in this complex region.

Materials and Methods: A 55-year-old male presented with left hemiparesis (motor power grade IV) lasting 20 days, with a medical history of type II diabetes and dyslipidemia. MRI and MRA revealed an enhancing lesion in the anterior aspect of the pons, with MRA suggesting a posterior fossa AV shunt at the right cerebellomedullary cistern. Cerebral angiography confirmed the presence of a DAVF at the posterior condylar vein, with feeding vessels originating from the right posterior meningeal artery. Although a transarterial embolization was planned, access to the venous pouch was hindered by focal luminal narrowing of the vertebral artery.

Results: Consequently, a hybrid approach was considered, involving lateral suboccipital craniotomy in a park bench position. A transjugular tubercle approach was utilized to coagulate the fistula location. An intraoperative transradial approach confirmed the complete obliteration of the fistula.

Conclusion: This case marks the first documented hybrid treatment of a rare DAVF in the posterior condylar vein, showcasing a safe and effective outcome. The integration of surgical and endovascular techniques demonstrates innovative problem-solving in addressing complex anatomical challenges. Key words: DAVFs, hypoglossal canal, posterior condylar vein, hybrid

A-040

A Case of Acute Middle Cerebral Artery Occlusion on the Side of Internal Carotid Artery Agenesis

Category: Acute Ischemic Stroke

Primary Author

Tatsuya Yano

Ainomiyako neurosurgery hospital Japan

Co-Author

-

Background and Purpose: Congenital absence of the internal carotid artery (ICA) is an exceedingly rare vascular anomaly that poses distinctive challenges in acute cerebrovascular event management. We report a rare case of mechanical thrombectomy for simultaneous occlusions of the middle cerebral artery (MCA) and posterior cerebral artery (PCA) territories secondary to cardioembolic stroke associated with congenital ICA agenesis.

Materials and Methods: An 86-year-old woman with a history of atrial fibrillation presented with sudden-onset impaired consciousness. On admission, she exhibited right hemiparesis, global aphasia, right hemispatial neglect, and right homonymous hemianopia, with a National Institutes of Health Stroke Scale (NIHSS) score of 20. Diffusion-weighted imaging (DWI) revealed extensive hyperintensity in the left occipital lobe and partial hyperintensity in the left MCA territory, with a DWI–Alberta Stroke Program Early CT Score (DWI-ASPECTS) of 8. Magnetic resonance angiography indicated occlusion at the left ICA origin and in the left PCA.

Results: Intravenous thrombolysis with tissue plasminogen activator (tPA) failed to achieve recanalization. Digital subtraction angiography via femoral access demonstrated complete absence of the left ICA from its origin. Retrospective review of MR cisternography suggested congenital absence of the ICA. Subsequent angiography via the left vertebral artery revealed that the left MCA was supplied through a prominent posterior communicating artery, with occlusions in the distal M1 and P2 segments. A 5-French Sofia aspiration catheter was used to achieve complete recanalization of the MCA occlusion. Cone-beam CT confirmed established infarction in the P2 territory; thus, thrombectomy for the PCA occlusion was not attempted. Postoperatively, right hemiparesis improved, but sensory aphasia, hemispatial neglect, and homonymous hemianopia persisted. Bone-window CT confirmed congenital left ICA agenesis. The patient was discharged with a modified Rankin Scale score of 4.

Conclusion: This case highlights the importance of considering congenital vascular anomalies in the differential diagnosis of apparent ICA occlusion during acute stroke evaluation. Awareness of such anomalies can prevent delays in diagnosis and optimize the management strategy.

A-041

Temporary coiling technic for cerebral vessel bleeding

Category: Others

Primary Author

Shinya Hagiwara

Alfried Krupp Krankenhaus, Department of Radiology and Neuroradiology, Germany

Co-Author

Jonas Schüssler

Alfried Krupp Krankenhaus, Department of Radiology and Neuroradiology

Elif Yamac

Alfried Krupp Krankenhaus, Department of Radiology and Neuroradiology

Ahmed Ayad

Alfried Krupp Krankenhaus, Department of Radiology and Neuroradiology

Batuhan Kara

Alfried Krupp Krankenhaus, Department of Radiology and Neuroradiology

René Chapot

Alfried Krupp Krankenhaus, Department of Radiology and Neuroradiology

Background and Purpose: In recent years, with the evolution of various devices, interventions for distal lesions have become widespread. With this trend, hemorrhagic complications caused by microwire arterial perforation or medullary artery injury have increased. We should deal with this problem appropriately.

Materials and Methods: We present two cases in which appropriate hemostasis was achieved using temporary coiling techniques.

Results: Case 1 Patient was a 67 years old female with an unruptured ACom. After the aneurysm embolization, head CT showed subarachnoid hemorrhage in the interhemispheric fissure. 7f ENVOY XB 100cm (CERENOVUS) was guided into the right internal carotid artery and Echelon10 (Medtronic) into the right A2, microangiography showed active bleeding. Echlon10 was advanced to the site of hemorrhage and HyperSoft Helical 1.5mm/4cm (Terumo Neuro) was deployed at the hemorrhage site without detachment. Marathon (Medtronic) was then guided to the right A2, and hemostasis was confirmed by microangiography from the Marathon while the coil was retrieved at the appropriate time. Case 2 Patient was a 86 years old female with an unruptured aneurysm at left A4-5 bifurcation. After Echelon10 was induced in left A5, active hemorrhage was observed at distal A5. Echlon10 was advanced to the site of bleeding and HyperSoft Helical 1.5mm/4cm was deployed at the site of bleeding without detachment. Scepter XC 4mm/11mm (Terumo Neuro) was subsequently guided to A3 and balloon inflated and flow controlled. Microangiography from Scepter XC confirmed hemostasis, and finally Scepter XC balloon was deflated and hemostasis was confirmed again.

Conclusion: Temporary coiling technic suggested the possibility of obtaining adequate hemostasis while avoiding ischemic complications.

A-042

Endovascular Treatment of ruptured wide-neck cerebral aneurysm

Category: Cerebral Aneurysm

Primary Author

Yuichiro Tsuji

Osaka Medical and Pharmaceutical University Japan

Co-Author

Ryo Hiramatsu

Osaka Medical and Pharmaceutical University

Masahiko Wanibuchi

Osaka Medical and Pharmaceutical University

Background and Purpose: The treatment of ruptured wide-neck cerebral aneurysm is still a challenge because of coil instability and a high recurrence rate. The aim of this study was evaluate the efficacy and safety of endovascular therapy for ruptured wide-neck cerebral aneurysms.

Materials and Methods: This two-center retrospective study aims to evaluate cases of ruptured wide-neck cerebral aneurysms treated by endovascular therapy from January 2015 to December 2024. Clinical records, aneurysm characteristics, initial occlusion rates and procedure- related complications were reviewed. A wide-neck aneurysm was defined as having a neck ≥ 4 mm or a dome/neck ratio (DNR) < 2.

Results: The analysis included 102 ruptured aneurysms treated by coil embolization. Double-catheter coil embolization (DCC) group (29 cases) showed significantly higher dome, neck, and height of aneurysm than in the balloon-assisted coil embolization (BAC) group (18 cases) and stent-assisted coil embolization (SAC) group (13 cases). Dome-neck ratio and aspect ratio did not differ among the three groups. Sufficient occlusion rates of DCC, BAC, and SAC including complete occlusion and neck remnant were observed 93.1%, 94.4%, 100%, respectively. Procedure related complications of DCC, BAC, and SAC were 3.4%, 5.5%, 30.7%, respectively. The rate of re-treatment for recurrence were 10.3% in the DCC and 22.2% in the BAC. All patients achieved successful endovascular treatment and no cases required alternative clipping surgery.

Conclusion: The DCC group achieved sufficient embolization in the acute phase, with relatively low rates of procedure-related complications and recurrence. DCC was considered to be an effective treatment for ruptured wide-neck cerebral aneurysms.

A-043

Endovascular Treatment of I ntracranial Aneurysms Using the Woven EndoBridge (WEB) Device: A Single-Center Experience

Category: Cerebral Aneurysm

Primary Author

Jinwook Baek

Department of Radiology, Inje University Busan Paik Hospital South Korea

Co-Author

Hae Woong Jeong

Department of Radiology, Inje University Busan Paik Hospital

Jin Lee

Department of Neurosurgery, Inje University Busan Paik Hospital

Juwhan Lee

Department of Neurosurgery, Inje University Busan Paik Hospital

Background and Purpose: The Woven EndoBridge (WEB) device is an intra- saccular flow disruptor designed for the treatment of wide-neck bifurcation aneurysms (WNBAs). This study aimed to evaluate the technical success, safety, and efficacy of WEB device deployment in a single tertiary center in Korea.

Materials and Methods: Between September 2021 and December 2024, 31 consecutive patients (21 females, 10 males; mean age: 65.0 years) with intracranial aneurysms underwent WEB device embolization. Target aneurysms were located at the MCA bifurcation (n=11), anterior communicating artery (n=10), basilar apex (n=9), and ICA terminus (n=1). Procedural data, immediate angiographic results, complications, and follow-up imaging outcomes were retrospectively analyzed.

Results: Technical success was achieved in all 31 cases (100%). Immediate angiographic outcomes demonstrated contrast stagnation within the device in every case. Follow-up imaging confirmed stable occlusion or progressive thrombosis in most aneurysms. One patient experienced hemoperitoneum unrelated to the neurointervention, recovering fully after gastrointestinal management. One patient died approximately one month after the procedure due to unrelated medical conditions.

Conclusion: The WEB device is a safe and effective option for treating wide-neck bifurcation aneurysms, offering high technical success rates and favorable mid-term angiographic outcomes with minimal complications.

A-046

Stent-assisted coil embolization and flow-diverting stent use for retreating recurrent vertebral artery dissecting aneurysms

Category: Cerebral Aneurysm

Primary Author

Young Dae Cho

Seoul National University Hospital South Korea

Co-Author

Ryo Hiramatsu

Osaka Medical and Pharmaceutical University

Masahiko Wanibuchi

Osaka Medical and Pharmaceutical University

Background and Purpose: Vertebral artery dissecting aneurysms (VADAs) sometimes recur after previous endovascular treatments. If there is evidence of changing size over time or if clinical symptoms worsen (due to mass effect), further retreatment is mandatory. The present study was conducted to assess potential differences in efficacy and safety profiles of additional stent-as- sisted coiling (SAC) and flow-diverting stent (FDS) use in patients with recurrent VADAs A total of 15 recurrent VADAs were subjected to SAC (n=7) or FDS (n=8) retreatment procedures between April 2009 and January 2023. We retrospectively reviewed pertinent medical records and radiologic data to compare efficacy and safety performances of these modalities.

Results: Mean values of maximal dissection length and aneurysm depth were 15.6 mm (range, 10.7-25.0 mm) and 13.9 mm (range, 6.3-29.4 mm) in the SAC group, compared with 15.4 mm (range, 7.2-23.6 mm) and 11.0 mm (range, 3.5-23.6 mm), respectively in the FDS group. In three of seven aneurysms, immediate successful occlusion was evident after SAC. There was immediate contrast stagnation in four of eight aneurysms following FDS placement. No procedure-related hemorrhagic or thromboembolic complications occurred in either group. However, follow-up angiography disclosed major recanalization in four members (57.1%) of the SAC group and in three members (37.5%) of the FDS group.

Conclusion: Reconstructive interventions have proven safe and effective in patients with recurrent VADAs. Unfortunately, follow-up outcomes after retreatment seem worse than initial therapeutic results, even for FDS devices. A larger cohort study is needed to corroborate these findings.

A-047

Mechanical thrombectomy of the occIusion of the ICA by spontaneous dissection

Category: Acute Ischemic Stroke

Primary Author

Myung Ho Rho

Sungkunkwan University School of Medicine, Kangbuk Samsung Hospital, Department of Radiolgy South Korea

Co-Author

Yusam Won

Sungkunkwan University School of Medicine, Kangbuk Samsung Hospital, Department of Neurosurgery

Piluk Chung

Sungkunkwan University School of Medicine, Kangbuk Samsung Hospital, Department of Neurology

Background and Purpose: Spontaneous internal carotid artery (ICA) dissection is a rare vascular disorder, predominantly affecting young adults. It typically presents with stroke-like symptoms due to ischemia in the corresponding vascular territory. Diagnosing ICA dissection can be challenging, as it may resemble pseudo-occlusion, which refers to isolated occlusion of the distal intracranial ICA. Management strategies generally align with those for large vessel occlusion secondary to atherosclerosis or thromboembolism.

Materials and Methods: We retrospectively reviewed data from patients with spontaneous ICA dissection treated at our institution during last 5 years, identifying 15 cases. Among these, three patients presented with complete ICA occlusion and underwent mechanical thrombectomy. All of them involved tandem occlusions of the ipsilat- eral middle cerebral artery (MCA). In two patients, ICA dissection was suspected prior to intervention based on computed tomography angiography (CTA), while in one case, the dissection was identified near the end of the procedure.

Results: In Case 1, a 32-year-old male presented with global aphasia and right hemiplegia (NIHSS 17, mRS 4). Dissection was confirmed via angiography, and carotid stenting from the proximal to distal cervical ICA was performed. Mechanical thrombectomy achieved complete recanalization (TICI 3), and at 90 days, NIHSS and mRS improved to 3 and 1, respectively. In Case 2, a 50-year-old male exhibited right-sided weakness and aphasia (NI- HSS 17, mRS 4). After contact aspiration removed a large thrombus, stent retrieval was used for MCA occlusion. Angiography revealed an intimal flap indicating dissection. The 90-day mRS was 3. Case 3 involved a 38-year-old male with global aphasia and right-sided weakness. CTA suggested poor collateral flow, and angiography revealed distal cervical ICA occlusion with dissection. Mechanical thrombectomy achieved recanalization (TICI 2b), and the 90-day mRS was 4.

Conclusion: Timely diagnosis and precise localization of the dissection and thrombus are crucial for improving outcomes following mechanical thrombectomy.

A-049

Impact of Age on Short-Term Outcomes Following Endovascular Thrombectomy in Acute Ischemic Stroke Patients Aged 70 and Older: Insights from a Regional Hospital in Taiwan

Category: Acute Ischemic Stroke

Primary Author

Pao-Sheng Yen

Department of Neuroradiology, Kuang Tien General Hospital, Taichung, Taiwan

Co-Author

Victor C. Kok

Department of Internal Medicine, Kuang Tien General Hospital, Taichung

Background and Purpose: The influence of clinical factors on post-endovascular thrombectomy (EVT) outcomes in patients aged 70 and older remains insufficiently explored. This study evaluates the regional hospital data to determine key predictors of favorable recovery, defined by a modified Rankin Scale (mRS) score of 0 to 2.

Materials and Methods This institutional ethics committee-approved study analyzed 94 patients aged 70 or older who underwent EVT for acute ischemic stroke. Participants were categorized into two groups: septuagenarians (n = 44) and octo/nonagenarians (n = 50). The study assessed post-EVT outcomes, including the modified Thrombolysis in Cerebral Infarction (mTICI) reperfusion grade, incidence of spontaneous intracerebral hemorrhage (ICH), and the modified Rankin Scale (mRS) score at three months post-EVT. A favorable outcome was defined as an mRS score of 0–2.

Results: Octo/nonagenarians had a significantly higher NIHSS score compared to septuagenarians (19.9 ± 6.1 vs. 16.9 ± 8.0, p = 0.0398), while their mean Alber- ta Stroke Program Early CT Score (ASPECTS) was notably lower (6.6 ± 2.4 vs. 7.8 ± 2.2, p = 0.0197). Additionally, higher Fazekas grades of leukoaraiosis were more frequently observed among octo/nona- genarians (p = 0.0297). Favorable modified Rankin Scale (mRS) outcomes were achieved in 27.3% of septuagenarians compared to only 8.0% of octo/ nonagenarians (p = 0.0274). Multivariate logistic regression analysis revealed that higher NIHSS scores (adjusted odds ratio [aOR] 1.10; 95% confidence interval [CI], 1.01–1.21) were predictive of poorer outcomes, whereas prior intravenous thrombolysis (aOR 0.24; 95% CI, 0.06–0.92) was a significant predictor of better outcomes. However, age was not independently associated with post-treatment outcomes.

Conclusion: This single-hospital study indicates that among patients aged 70 and older, advanced age is not an independent predictor of poorer outcomes following endovascular thrombectomy (EVT) for acute ischemic stroke.

A-050

Outcomes of Flow-Diverter Stents in Intracranial Aneurysms: Prognostic Factors of Incomplete Occlusion and In-Stent Stenosis

Category: Cerebral Aneurysm

Primary Author

Kanisorn Sungkaro

Siriraj Thailand

Co-Author

Pattarawit Withayasuk

Siriraj Hospital

Ekawut Chankaew

Siriraj Hospital

Thaweesak Aurboonyawat

Siriraj Hospital

Anchalee Churojana

Siriraj Hospital

Boonrerk Sangpetngam

Siriraj Hospital

Background and Purpose: Flow-diverter stents (FDS) have transformed the treatment landscape for intracranial aneurysms, offering superior occlusion rates compared to conventional endovascular approaches. Despite their effectiveness, complications such as incomplete occlusion and in-stent stenosis continue challenging long-term success.

Materials and Methods: We retrospectively reviewed 104 intracranial aneurysms treated with FDS at a tertiary referral center (2019–2023). Patient demographics, aneurysm characteristics (size, location, morphology), prior treatments, and procedural details (FDS type, neck coverage, medications) were collected. Angiographic outcomes at approximately 12 months were recorded as occlusion rate. ISS was defined as any luminal narrowing within the stent on follow-up angiography. Logistic regression models were used to identify prognostic factors.

Results: The cohort had a mean age of 56.47 years (±13.06) with 77.8% females. Aneurysms were predominantly unruptured (83.6%) and located in anterior circulation (77%). The mean aneurysm dome width diameter was 7.21 ± 5.34 mm. Fourteen aneurysms (13.5%) had prior treatment (5 clipping, 4 stent assisted coiling). Complete FDS coverage of the aneurysm neck was achieved in 81 cases (77.9%). At a median follow-up of 12 months, complete occlusion was achieved in 60.4% of aneurysms. ISS was observed in 28 cases (30.1%), mostly neointimal lining: 78.5% of ISS cases. Multivariable analysis identified clopidogrel use (OR 4.86, p = 0.02), larger dome width (per mm, OR 1.13, p = 0.02), and incomplete neck coverage (OR 9.20, p = 0.01) as independent prognostic factors of incomplete aneurysm occlusion. For ISS, ticagrelor use was an independent prognostic factor (OR 5.30, p = 0.03). No aneurysm re-ruptures occurred during follow-up. There was no ISS requiring retreatment.

Conclusion: FDS achieved effective aneurysm occlusion in most cases. Incomplete occlusion was more likely in aneurysms with larger dome size or incomplete device coverage of the neck, and among patients on clopidogrel. ISS occurred in about one-third of cases (mostly mild); use of ticagrelor was associated with higher ISS risk. These findings align with emerging evidence that aneurysm size, morphology, and device-apposition factors influence occlusion, while biological factors influence ISS. Optimizing patient selection and device strategy – including ensuring full neck coverage and appropriate FDS sizing – may improve occlusion outcomes and minimize ISS.

A-051

General anaesthesia for acute ischaemic stroke mechanical thrombectomy, a single centre experience in Hong Kong and review of recent literature.

Category: Acute Ischemic Stroke

Primary Author

Ivan Hoi Wei Cheung

Queen Mary Hospital (Radiology) Hong Kong

Co-Author

Edward Chu

Queen Mary Hospital (Radiology)

James Zhuang

Queen Mary Hospital (Neurosurgery)

Clara Poon

(Queen Mary Hospital (Anaesthesia))

Background and Purpose: Debate surrounding the anaesthesia of choice for mechanical thrombectomy treatment in acute ischaemic stroke (AIS) is still contentious. It is commonly separated into general anaesthesia (GA), or non-general anaesthesia (non-GA), which include conscious sedation and/or local anaesthesia. Each anaesthesia method has its advantages and drawbacks. Many stroke centre practice is likely dependent on local traditional practice and resource availability. Queen Mary Hospital (QMH) is a regional stroke centre with 24 hours service for intravenous thrombolytics and endovascular therapy (EVT) for acute ischaemic stroke. We have a robust anaesthetic team who can dedicate urgent service for EVT. Given current published literature, our centre is a proponent for GA and nearly all cases of mechanical thrombectomy are performed under GA. We aim to share our stroke centre experience and add to the current literature.

Materials and Methods: Retrospective review from a prospectively maintained database of mechanical thrombectomy cases for AIS from January 2023 to December 2024 was performed. Data including demographics, procedural time metrics and clinical outcomes were extracted for analysis. A review of recent literature and trials around this topic will also be discussed, including their outcomes, relevance of clinical factors and comparison to our local data.

Results: We aim to share our stroke centre experience with figures on logistics, time metrics, practicality and outcomes, whilst comparing with the literature.

Conclusion: There is still ongoing debate on the optimal choice of anaesthesia in mechanical thrombectomy for acute ischaemic stroke. The wide heterogeneity of presenting clinical background renders difficulty in determining an absolute advantage of GA or non-GA as a set standard for all cases. The likely reality remains that GA vs non-GA should be adapted to the clinical scenario and tailoring by weighing up relevant individual parameters. At present in our centre, we have found GA in most cases to be safe and effective in keeping with literature.

A-055

The useful “ C stenting” technique for wide neck basilar apex aneurysms

Category: Cerebral Aneurysm

Primary Author

Yume Suzuki

Mie University Graduate School of Medicine Japan

Co-Author

Ahmed Ayad

Alfried Krupp Hospital

Elif Yamac

Alfried Krupp Hospital

Shinya Hagiwara

Alfried Krupp Hospital

Jonas Schüssler

Alfried Krupp Hospital

René Chapot

Alfried Krupp Hospital

Background and Purpose: Large wide-necked basilar artery (BA) apex aneurysms remain difficult to manage despite advances in endovascular strategies. These aneurysms are associated with high recurrence rates and procedure-related complications, including stenosis of the parent artery, occlusion of perforating branches, and in-stent thrombosis. We introduce a novel endovascular technique, which we named “ C stenting”, designed to treat complex-shaped BA aneurysms with wide necks involving the proximal segments of the posterior cerebral arteries (PCAs) or the superior cerebellar arteries (SCAs).

Materials and Methods: The “ C stenting” technique involves a bidirectional approach. From the anterior circulation, a stent or flow diverter is deployed from the ipsilateral SCA to the PCA via the posterior communicating artery (PCoA). From the posterior circulation, an additional stent or flow diverter is placed from the contralateral PCA to the BA or to the contralateral SCA. This dual-access method is combined with coil embolization to achieve aneurysmal occlusion.

Results: Four patients were treated using this technique. The maximum aneurysmal diameter ranged from 10 to 35 mm, and three aneurysms were partially thrombosed. In three cases, stents were placed between the unilateral SCA and PCA and from the contralateral PCA to the BA. In one case, bilateral SCA-PCA stenting was performed. One case required additional flow diverters. However, all patients achieved favorable outcomes during the further follow-up period.

Conclusion: The “ C stenting” technique is a promising treatment option for complex BA apex aneurysms, particularly in cases with well-developed PCoAs. This approach may provide a new therapeutic strategy for aneurysms that are difficult to treat using conventional methods.

A-056

Endovascular Treatment of Complex Brain Aneurysms

Category: Cerebral Aneurysm

Primary Author

Umair Rashid Chaudhry

Department of Neuroradiology, Lahore General Hospital, Lahore, Pakistan

Co-Author

-

Background and Purpose: Endovascular treatment of complex aneurysms may be challenging. Balloon remodeling, stent-assisted Coiling, FD, contour, WEB and multiple micro-catheter techniques were all developed for endovascular treatment of such aneurysms. However, these techniques may not be needed in case of acute angulation between proximal and distal parent arteries due to the difficultly of reaching the distal edge of the aneurysm. This study is conducted to assess the complex aneurysm coiling with and without Assisted Techniques.

Materials and Methods: This study was conducted from July 2015 to December 2024 at the department of Neuroradiology, Lahore General Hospital, Lahore Pakistan. A total of 500 patients with cerebral aneurysms around the circle of will is and posterior circulation were including in the study of both genders.

Results: Out of 500 patients, there were 200 males and 300 female patients. Their age ranged from 22 - 65 years. The maximum numbers of patients were in their fifth and sixth decade of life. In our study successful endovascular treatment is were done in all patients with minimal recurrence/recanalization of cerebral aneurysms at MCA. Only 08 patients developed dense hemiplegia and 02 died.

Conclusion: In complex aneurysms endovascular treatment is effective safe and methodologically simpler than clipping.

A-057

Outcome of Rescue treatment after failed mechanical thrombectomy in Intracranial Atherosclerosis related Large Vessel Occlusion (ICAS-LVO)

Category: Acute Ischemic Stroke

Primary Author

Meitee Vichutavate

Siriraj hospital Thailand

Co-Author

Thaweesak Aurboonyawat

Siriraj hospital

Anchalee Churojana

Siriraj hospital

Pattarawit Withayasuk

Siriraj hospital

Boonrerk Sangpetngam

Siriraj hospital

Ekawut Chankaew

Siriraj hospital

Background and Purpose: ICAS-LVO is one of the most common causes of failed mechanical thrombectomy (MT), especially in the Asian population. We evaluated the effectiveness and safety outcomes of rescue treatment (RT) in acute ischemic stroke caused by ICAS-LVO.

Materials and Methods: We conducted a retrospective study of acute ischemic stroke patients with ICAS-LVO enrolled between 2020 and 2024. Study outcomes included the modified Rankin Scale (mRS) at 1, 3, and 12 months, and the rate of symptomatic intracerebral hemorrhage (sICH). Outcomes were compared between patients who received conservative treatment (non-RT) and those who underwent RT.

Results: A total of 92 consecutive patients were included, of whom 56 received RT (balloon angioplasty = 14, rescue stenting = 26, balloon angioplasty with stenting = 10). The favorable outcomes (mRS 0–2) at 1, 3, and 12 months were not significantly different between the non-RT and RT groups (39% vs 43%, P = 0.80 at 1 month; 42% vs 45%, P = 0.80 at 3 months; and 36% vs 43%, P = 0.50 at 12 months). Successful recanalization (mTICI ≥ 2b) was higher in the RT group (61% vs 84%, P = 0.03). The sICH rate was higher in the non-RT group (19% vs 9%, P = 0.20), but the difference was not statistically significant. The recurrent ischemic stroke rate was also higher in the non-RT group (11% vs 7%, P = 0.14). Other bleeding sites were more frequent in the RT group (3% vs 11%, P = 0.20). The stent occlusion rate after RT was 13%.

Conclusion: In acute ischemic stroke patients with ICAS-LVO, RT after failed MT did not demonstrate a significant difference in favorable outcomes after a 12-month follow-up period. However, RT tended to reduce the rates of sICH and recurrent ischemic stroke. Conversely, bleeding at other sites may be a concern following RT.

A-059

Ozonucleolysis in cervical radiculopathy

Category: Others

Primary Author

Umair Rashid Chaudhry

Department of Neuroradiology, Lahore General Hospital, Lahore, Pakistan

Co-Author

-

Background and Purpose: Our experience with ozonucleolysis between June 2005 to December 2024 with 8000 patients affected by pain cervical region (Bracehalga) due to disc herniation including of postoperative recurrence disc prolapsed.

Materials and Methods: All these cases treated by intradiscal ozone injections. Patients age between 20 to 70 years underwent percutenous ozoneuclealysis. The procedure done under the angiofioursocopy with full aspectic technique. The ozone generator, essential component placed close to the patients. Simple 23G needle to 22G spinal needle, (quincke type point) were used to inject ozone under fluoroscopy. No premedication or anesthesia were given and the procedures were performed at an outpatient facility with short hospital stay after the treatment.

Results: Among 8000 patients 4200 patients were followed up for 5 months, 50% of the treated patients showed complete recovery with disappearance of symptoms. 25% of cases complaint of occasional episodes of pain neck and arms but no limitations of occupational activities – 15% of the cases showed in sufficient improvement – 5% cases no improvement and went for surgery 10% of the cases never turned up after the first visit. Most of these patient had no FDA surgical indication. The patients who failed to benefit from ozonucleolysis underwent surgery. In all these cases, the previous O2 O3 gas therapy had no negative effects on the surgical procedure.

Conclusion: In our experience, ozonucleolysis of cervical herniated disc has revolutionized the percutenous approach to nerve root disease making it safer cheaper and easier to repeat than treatments currently in use. So ozonucleolysis should be 1st choice of treatment in cervical disc prolapse.

A-061

Overcoming vascular limitations: direct percutaneous embolisation for spinal tumour control

Category: Spinal vascular diseases

Primary Author

Si Zhao Tang

National University Hospital, National University Health System Singapore

Co-Author

Gopinathan Anil

National University Hospital, National University Health System

Background and Purpose: Pre-operative embolisation in surgical planning and management of spinal metastases aims to minimise intraoperative blood loss, shorten surgical time, and facilitate post-operative recovery. However, in certain regions such as the cervical spine, transarterial embolisation may carry unacceptable risks. In other cases, complex or stenotic vascular anatomy may preclude selective arterial cannulation and embolisation. This study presents two cases utilising direct percutaneous embolisation as a safe and effective alternative.

Materials and Methods: Two patients with spinal metastatic disease were evaluated. In both cases, standard transarterial embolisation was either unsafe or not technically feasible. Under fluoroscopic and cone beam CT guidance, direct percutaneous embolisation using Glubran mixed with Lipiodol was performed through spinal needles into the tumour parenchyma. Procedural technique, precautions taken, and intra-procedural imaging confirmation were documented.

Results: Case 1: A patient with metastatic renal cell carcinoma presented with an L1 pathological fracture and spinal cord compression. Severe vascular atherosclerosis and ectasia rendered selective embolisation impossible. Direct percutaneous embolisation achieved good tumour devascularisation and retrograde occlusion of feeding vessels without complications. Case 2: A patient with metastatic papillary thyroid carcinoma had a large C6/C7 mass. Transarterial embolisation was incomplete due to the proximity of critical cervical arteries. Subsequent percutaneous embolisation achieved good tumour penetration of embolic material with no immediate complications. Both patients subsequently underwent successful spinal surgery.

Conclusion: Direct percutaneous embolisation is an important alternative when conventional transarterial techniques are limited by anatomical constraints or risk profiles. Careful planning, meticulous image guidance, and understanding of local vascular anatomy are critical to ensure safe and effective tumour devascularisation in spinal metastases.

A-062

Endovascular EEG device prospective multicenter single-arm clinical trial to confirm efficacy and safety performance on intractable epilepsy -EPSILON IE trial-

Category: Others

Primary Author

Yuji Matsumaru

University of Tsukuba Japan

Co-Author

Hirokatsu Masuda

University of Tsukuba

Kota Araki

University of Tsukuba

Hisayuki Hosoo

University of Tsukuba

Ayataka Fujimoto

Seirei Hamamatsu Hospital

Background and Purpose: Focal resection for refractory epilepsy is an extremely effective treatment, but diagnosis of its focus often requires invasive intracranial electrode placement. We developed an intravascular EEG electrode (EP01) as a minimally invasive method, and reported that it is possible to diagnose focus lateralization in vivo, and that an FIH study showed that it was possible to obtain EEG recordings with higher sensitivity than scalp EEG, and that multiple electrodes up to 6 could be placed into venous sinuses. In order to verify whether EP01 is capable of diagnosing focus lateralization in the same way as conventional intracranial electrodes, we started a multicenter prospective single-arm study (EPSILON IE) in March 2024 in Japan.

Materials and Methods: Patients with refractory focal epilepsy aged 15 to 70 years who undergo conventional intracranial electrode placement and have appropriate vascular anatomy. EP01 is placed in the bilateral cavernous sinuses, bilateral transverse sinuses, and superior sagittal sinus at the same time as conventional intracranial electrodes, and video-EEG recording is performed for up to 2 weeks. PE was defined as the concordance rate between EP01 with non-invasive testing for focal lateralization diagnosis and that of conventional intracranial electrodes. The planned number of cases is 37.

Results: 17 cases had enrolled by March 2025.

Conclusion: The EPSILON IE trial is progressing smoothly and is scheduled to complete enrollment within a year.

Disclose all financial interests: Yuji Matsumaru and Ayataka Fujimoto and Kouta Araki and Hisayuki Hosoo are stock holders of Epsilone Medical

A-063

Angiographic Predictors of Immediate Obliteration in Lateral Sinus DAVFs Treated with EVOH-Based Endovascular Theragy

Category: Dural Arteriovenous Fistulae

Primary Author

Chung Jung Lin

Taipei Veterans General Hospital Taiwan

Co-Author

Chao Bo Luo

Taipei Veterans General Hospital

Feng Chi Chang

Taipei Veterans General Hospital

Yong-Sin Hu

Taipei Hospital, Ministry of Health and Welfare

Chung-Han, Yang

Taipei Veterans General Hospital

Hsuen En Hwang

Taipei Veterans General Hospital

Background and Purpose: Advances in liquid embolic agents (e.g., EVOH) and endovascular devices have improved immediate occlusion rates for dural arteriovenous fistulas (DAVFs). However, lateral sinus DAVFs remained challenging, often requiring multiple sessions for complete occlusion. The purpose of this study was to identify angiographic factors predicting immediate obliteration of lateral sinus DAVFs in a single endovascular treatment session.

Materials and Methods: We retrospectively analyzed patients with lateral sinus DAVFs treated by endovascular embolization (transarterial and/or transvenous) using EVOH with intent to cure in one session. Patients with prior DAVF treatments (endovascular, surgical, or radiosurgery), venoplasty, or those not treated with EVOH were excluded. Pre-treatment angiograms were reviewed for arterial feeder characteristics (number and presence of angiogenic/diffuse feeders), Cognard classification, fistula location (proximal vs distal transverse-sigmoid sinus), and a combined conduit score (CCS) quantifying venous outflow patency across sinus segments. The treatment approach (transarterial via occipital artery vs other, or transvenous) and use of adjunctive measures (coils, balloon, or periprocedural anticoagulation) were recorded. Immediate obliteration was defined as complete disappearance of the fistula on angiography at the end of the first session. Statistical analysis identified associations between these factors and immediate obliteration.

Results: Fifty-six patients met the inclusion criteria. Immediate angiographic obliteration in one session was achieved in 37 patients (66%). Cases with angiogenic arterial supply, an occipital artery feeder, higher CCS, or distal sinus location had significantly lower one- session cure rates (each p < 0.05). In contrast, adjunct use of coils, balloon assistance, or anticoagulation did not significantly influence immediate obliteration rates (p > 0.05). Procedure-related complications were minimal: one patient (1.7%) had a cranial nerve injury and one (1.7%) had transient worsening of venous congestion; no permanent neurological deficits occurred.

Conclusion: Several angiographic features predicted failure of immediate complete obliteration in lateral sinus DAVFs. Notably, lesions with benign presentation (Cognard I, presenting with tinnitus) were the most difficult to cure in one session. Careful angiographic assessment helped predict single-session success and guided patient counseling

A-065

Evaluating the Safety and Efficacy of 3-Month Dual Antiplatelet Therapy After Carotid Artery Stenting: A Propensity Score-Matched Retrospective Study

Category: Acute Ischemic Stroke

Primary Author

Taisuke Akimoto

Yokohama City University Japan

Co-Author

Manato Kishi

Yokohama City University

Yu Iida

Yokohama City University

Shigeta Miyake

Yokohama City University

Katsumi Sakata

Yokohama City University

Yasunobu Nakai

Yokohama City University

Background and Purpose: The optimal duration of dual antiplatelet therapy (DAPT) following carotid artery stenting (CAS) remains uncertain. This study aimed to compare clinical outcomes between two DAPT duration strategies 3-month versus extended therapy across four centers, focusing on the balance between ischemic prevention and hemorrhagic risk.

Materials and Methods: We retrospectively analyzed 347 patients who underwent CAS between 2010 and 2022. Patients were stratified into two groups based on DAPT duration: 3 months or longer than 3 months. Baseline characteristics, postprocedural ischemic events, and DAPT-related hemorrhagic complications were assessed. Propensity score matching was performed, resulting in 80 matched pairs for analysis.

Results: Among the matched cohort, ischemic events including cerebral infarction and transient ischemic attacks occurred in 4 patients in the 3-month group and 10 in the >3-month group. Hemorrhagic complications were observed in 2 and 7 patients in the respective groups. The log-rank test demonstrated a significantly higher incidence of hemorrhagic events in the >3-month DAPT group (hazard ratio [HR] 6.21, 95% confidence interval [CI] 1.23–31.4, p = 0.014). There was no statistically significant difference in ischemic event rates between the groups (HR 2.90, 95% CI 0.89–9.46, p = 0.077).

Conclusion: A 3-month DAPT regimen following CAS appears to be both safe and adequate for most patients. While prolonged therapy may be considered in selected high-risk cases, routine extension of DAPT beyond 3 months does not seem justified based on ischemic outcomes and is associated with increased bleeding risk.

A-066

Strategy of AVM embolization based on the types of vessels and embolic materials

Category: Cerebral Arteriovenous Malformation

Primary Author

Mitsuhito Mase

Department of Neurosurgery, Nagoya City Unversity Graduate School of Medical Sciences, Japan

Co-Author

Yusuke Nishikawa

Department of Neurosurgery, Nagoya City Unversity Graduate School of Medical Sciences

Tomoyasu Yamanaka

Department of Neurosurgery, Nagoya City Unversity Graduate School of Medical Sciences

Yasuhiro Inoue

Department of Neurology, Nagoya City Unversity Graduate School of Medical Sciences

Mitsuru Uchida

Department of Neurosurgery, Nagoya City Unversity Graduate School of Medical Sciences

Masahiro Omura

Department of Neurology, Nagoya City Unversity Graduate School of Medical Sciences

Background and Purpose: In embolization of AVMs, now, two different types of embolic materials (Onyx and NBCA: n-butyl-2-cyano- acrylate) are available However, there were no cer- tain rules of the choice and use of them. The purpose of this retrospective study is to clarify the appropriate choice of the materials by analyzing the types of em- bolized feeder (perforator or cortical artery) and the clinical results of AVM embolization.

Materials and Methods: The study includes 11 patients with AVMs treated by trans-arterial embolization (TAE) from June 2018 to May 2022 in our institute.

Results: Multi-sessions of TAE were performed in 4 of 11 cas- es. Surgical removals of niduses were necessary for 9 cases. After these procedures, all AVMs disappeared. Totally, 33 arteries were embolized (13 perforators, 20 cortical arteries). All perforators were embolized using NBCA, resulting in nidus embolization (NE) in 6 of 13 cases (46%). Cortical arteries were embolized using NBCA, Onyx, or coils (11, 8, 1 case, respectively), re- sulting in NE in 8 of 11 cases (72%) using NBCA and 8 cases (100 %) using Onyx. NE rate of Onyx was significantly higher compared to NBCA. The reasons why we did not use Onyx were as follows; 1) torturous vessels with high risk of hemorrhage in withdrawal of a microcatheter, or difficult accessibility (6 cases), 2) existence of normal arteries proximally near to nidus (2 cases), 3) no use of distal access catheter due to thin vessels in pediatric patients (2 cases). There were two cases of complication (subarachnoid hemorrhage due to catheter removal after Onyx, and infarction due to migration of NBCA), which did not affect mRS on discharge.

Conclusion: In our institute, NBCA tends to be used for perforator, and Onyx for cortical artery. Onyx requires a certain proximal safety margin because of back flow, which is not suitable for perforators. This decision is main- ly made depending on proximal existence of normal artery.

A-067

Falcotentorial dAVF with Hydrocephalus: Review of a Rare Case with a Strategic Embolization to Prevent Progression of Hydrocephalus

Category: Dural Arteriovenous Fistulae

Primary Author

Made Bhuwana Putra

Prof Ngoerah Hospital Indonesia

Co-Author

Hirokazu Nagasaki

Kawasaki Saiwai Hospital

Narikiyo Michihisa

Kawasaki Saiwai Hospital

Kohei Yamamoto

Kawasaki Saiwai Hospital

Takashi Kawagoe

Kawasaki Saiwai Hospital

Yoshifumi Tsuboi

Kawasaki Saiwai Hospital

Background and Purpose: Dural arteriovenous fistula (dAVF) is an abnormal connection between arteries and veins located around or within the dural venous sinuses, intradural pial, or meningeal veins, accounting for 10–15% of all cerebrovascular malformations. Falcotentorial dAVF with the development of hydrocephalus is an exceptionally rare condition, with only a handful of cases reported. In this paper, we describe the technical details of the management of falcotentorial dAVF with hydrocephalus.

Materials and Methods: A 56-year-old male presented to our hospital clinic with walking difficulty and symptoms of dementia since 3 months prior. Magnetic resonance angiography (MRA) shows hydrocephalus with vascular malformation at the level of the third ventricle. Digital subtraction angiography (DSA) shows dAVF formation at the junction of falx and tentorium cerebelli, with multiple feeders and multiple deep venous drainage, and venous varices compressing the sylvian aqueduct, causing hydrocephalus. Trans-arterial embolization was done with complete occlusion of the fistula and preservation of venous varices. The patient tolerated the procedure well with resolution of the hydrocephalus.

Results: The cause of hydrocephalus in dAVF case is mainly obstruction of the sylvian aqueduct by the venous dilation. Treating hydrocephalus prior to downgrading or curing the dAVF may instigate intracranial hemorrhage by damaging the distended leptomeningeal vessels. During embolization, we are particularly careful to preserve the venous varix, which is located at the most caudal part of the fistula. Embolization of the venous pouch may cause acute thrombosis and varix acute dilation by the thrombosis formation, which may worsen the occlusive hydrocephalus. Following embolization, the hydrocephalus eventually resolves with improved clinical condition.

Conclusion: Falcotentorial dAVF with hydrocephalus is an exceptionally rare case. Preservation of the venous ectasia pouch compressing the Sylvian aqueduct during the embolization procedure may prevent the exacerbation of hydrocephalus and subsequently reduce the volume of the ventricle.

A-068

Exclusive Middle Meningeal artery Embolisation for treatment of large Chronic Subdural Hematoma in Elderly Patients :A case Series

Category: Vascular Trauma

Primary Author

Goutham Selvam Periasamy

Stroke and Neurointervention Foundation (SNIF) , VIMS HOS- PITALS, India

Co-Author

-

Background and Purpose: Former studies have demonstrated safety and effec- tiveness of MMA embolization as both adjuvant and primary therapy for chronic Sub Dural Hematoma. However , data are limited regarding its use as a Exclusive approach in Managing large cSDH Volume > 150 ml in elderly patients

Materials and Methods: we reviewed consecutive MMA embolization referrals and included patients aged >/= 75 with mFI >= 2 who received stand-alone treatment for Chronic sub dural hematoma and had atleast one follow up imaging .

Results: A total of 15 patients met the inclusion and frailty criteria. The average age was 83+/- 5.8 yr. The average initial chronic sub dural hematoma volume was 160 +/- 30 ml , with average midline shift of 7.0 +/- 2 mm . average length of stay was 2 +/- 1 day. There was no intra or post procedural complications.

Conclusion: In Elderly and frail Patients with large Chronic sub dural hematomas exclusive MMA embolisation was effective in decreasing the volume and improving the clinical condition with significant reduction in the morbidity and mortality

A-069

Phase Selection of Venous Opacity on Multiphase CTA for Outcome Prediction in Acute Ischemic Stroke

Category: Acute Ischemic Stroke

Primary Author

Thanit Nanthanasub

Department of Radiology, Faculty of Medicine Siriraj Hospital,, Mahidol University, Thailand

Co-Author

Wanichaya Srirattana

Department of Radiology, Faculty of Medicine Siriraj Hospita

Sittaya Buatong

Department of Radiology, Faculty of Medicine Siriraj Hospita

Utarat Kaewumporn

Department of Radiology, Faculty of Medicine Siriraj Hospita

Dittapong Songsaeng

Department of Radiology, Faculty of Medicine Siriraj Hospita

Background and Purpose: Selecting appropriate candidates for mechanical thrombectomy in acute ischemic stroke remains challenging. Contrast-enhanced imaging markers have been proposed, including arterial phase pa- rameters, multiphase CTA (mCTA) collateral scores, and venous-phase indicators such as the PRECISE score, which utilizes venous opacity (VO) as a sur- rogate. While VO data become increasingly available across all three mCTA phases, a recent study by Yue Chu et al. (2024) suggested using the peak VO across phases. However, the peak selection approach may face practical inconvienience in clinical settings, as it requires multiple VO comparisons across all three mCTA phases. This study aims to identify a simplified strategy for VO phase selection by determining whether VO from a single representative phase can reliably predict 90-day functional outcomes, as measured by the modified Rankin Scale (mRS).

Materials and Methods: A retrospective cohort study was conducted at Siriraj Hospital between January 2020 and December 2023, including 505 patients with anterior circulation acute ischemic stroke who underwent mechanical throm- bectomy. VO scores were recorded across the three phases of mCTA. Multivariable logistic regression analysis was performed to evaluate the predictive val- ue of VO for 90-day outcomes (mRS), while adjust- ing for collateral circulation, baseline NIHSS scores, mTICI grades, and the presence of intracranial hem- orrhage (ICH) or brain edema. Functional outcomes were dichotomized into good (mRS ≤ 2) and poor (mRS > 2).

Results: A favorable VO score in the first mCTA phase was significantly associated with good functional outcomes (mRS ≤ 2 in 74% vs. 49%; p < 0.001). High collateral scores (grades 4–5) were also linked to better recovery (91% vs. 77%; p = 0.004). Multivariate analysis confirmed first-phase VO (OR = 0.49; p = 0.022), high collateral scores (OR = 2.84; p = 0.015), and the absence of ICH or brain edema (OR = 0.20; p < 0.001) as independent predictors of favorable outcome.

Conclusion: Among the three mCTA phases, VO from the first phase and collateral circulation scoring emerged as the strongest predictors of 90-day functional outcome. Emphasizing early-phase VO assessment and collateral evaluation may enhance prognostication and clinical decision-making in patients undergoing mechanical thrombectomy.

A-073

Endovascular Trapping of a Giant Cervical ICA Aneurysm: Coil Anchoring Techniques in High-Flow Vessels.

Category: Other Neurovascular and Rare Diseases

Primary Author

Yuk Yiu Ng

Queen Mary Hospital Hong Kong

Co-Author

Yin Lun Edward Chu

Queen Mary Hospital

King Fai Kevin Cheng

Queen Mary Hospital

Tin Fong James Zhuang

Queen Mary Hospital

Background and Purpose: Embolisation in high flow artery is challenging as there is increase risk of coil migration. We report a case of endovascular trapping for a giant (11 cm) non-functioning cervical internal carotid artery (ICA) aneurysm causing mass effect (cervical discomfort, shoulder pain) and harboring turbulent flow with an increased risk of thromboembolism or rupture. Given progressive enlargement and symptoms, patient underwent endovascular ICA trapping after passing balloon occlusion testing (BOT).

Materials and Methods: Technical Strategy Distal Outflow Occlusion: A microcatheter was navigated across the aneurysm to reach the distal outflow segment. Coil embolization was performed distal to the aneurysm to prevent retrograde filling. Proximal Inflow Control: A balloon catheter was inflated proximally to reduce antegrade flow during coil deployment. High-density coil packing created a stable proximal “plug.” Coil Anchoring with Glue (NBCA): N-butyl cyanoacrylate (NBCA) was injected to form a rigid cast, securing the coils against migration in the high-flow ICA.

Results: Final angiography confirmed complete aneurysm trapping with preserved cross-flow from the contralateral ICA. The patient showed symptomatic relief and no neurological deficits post-procedure.

Conclusion: This case demonstrates a safe and effective trapping technique for giant cervical ICA aneurysms, emphasizing distal-proximal coil occlusion, flow control, and glue augmentation to ensure coil stability in high-flow vessels.

A-075

Predictive Factors of Favorable Outcomes Following Mechanical Thrombectomy: A Prospective Study

Category: Acute Ischemic Stroke

Primary Author

Niimron Nisahoh

Siriraj hospital Thailand

Co-Author

Thaweesak Aurboonyawat

Siriraj Hospital, Mahidol University

Sakda Sathirareuangchai

Siriraj Hospital, Mahidol University

Pensiri Srishewachart

Siriraj Hospital, Mahidol University

Anchalee Churojana

Siriraj Hospital, Mahidol University

Pattarawit Withayasuk

Siriraj Hospital, Mahidol University

Background and Purpose: Mechanical thrombectomy (MT) has become the standard treatment of ischemic stroke patients with large vessel occlusion in Siriraj Hospital and has shown comparable favorable outcomes, but still a lack of understanding of factors influencing outcomes. This study aimed to evaluate the effectiveness of mechanical thrombectomy after the Siriraj Stroke Fast Track Activation Protocol and identify predictors of favorable outcomes.

Materials and Methods: A single-center prospective cohort study enrolled 120 consecutive patients with large vessel occlusions who underwent MT between April 2023 and August 2024. The objectives were favorable outcomes at 3 months and factors influencing favorable outcomes.

Results: Among 120 patients (median age 68 years, with 53% male), 57% achieved favorable outcomes at 3 months. Successful recanalization (mTICI ≥2B) was achieved in 85%, with first-pass success in 42%. Safety profiles show a 7.5% mortality rate and 3.3% symptomatic ICH. Independent predictors of favorable outcomes included male gender (aOR 6.97, p= 0.016), non- diabetic status (aOR 10.30, p= 0.011), successful recanalization (aOR 33.92, p=0.003), minimum diastolic blood pressure during procedure ≥55 mmHg (aOR 17.19, p=0.004), extubation within 24 hours (aOR 9.14, p=0.010), post-operative NIHSS at 24 hours less than 16 (aOR 292.11, p=0.001), absence of significant abnormality on 24-hours imaging (aOR 20.28, p=0.022) and red/mixed thrombus composition (aOR 7.97, p=0.023)

Conclusion: The outcomes of mechanical thrombectomy at Siriraj Hospital align with global studies. This study identified several factors influencing favorable outcomes, including unique local predictors such as thrombus composition. These help optimize patient selection and periprocedural and postoperative management to improve the outcomes.

A-077

3D to the Rescue: Unmasking a Hidden M2 Occlusion During Mechanical Thrombectomy with 3D Rotational Angiography

Category: Acute Ischemic Stroke

Primary Author

Hooi Lam Tan

Radiology Department / Universiti Teknologi MARA (UiTM) Malaysia

Co-Author

Yuh Yang Leong

Radiology Department / Hospital Canselor Tuanku Muhriz UKM

Muhammad Zahid Abdul Muien

Radiology Department / Hospital Canselor Tuanku Muhriz UKM

Siti Shakira Suhaimi

Radiology Department / Hospital Canselor Tuanku Muhriz UKM

Zhe Kang Law

Neurology Department / Hospital Canselor Tuanku Muhriz UKM

Background and Purpose: Two-dimensional (2D) biplane Digital Subtraction Angiography (DSA) is the standard imaging modality used during mechanical thrombectomy for acute ischemic stroke. However, in certain cases, particularly those involving distal branch occlusions, DSA may fail to identify the site of vessel blockage, especially in the absence of a visible stump. Three-dimension- al Rotational Angiography (3D RA), although not routinely used in this context, can provide enhanced spatial resolution and detailed vessel mapping.

Materials and Methods: A patient with acute ischemic stroke presented with a CT angiography-confirmed left M1 middle cerebral artery (MCA) occlusion. Intravenous tenecteplase was administered, and the patient was brought for mechanical thrombectomy. Initial 2D biplane DSA showed spontaneous recanalization of the M1 segment. However, persistent hypoperfusion was observed in the territory of the superior division of the left M2 segment. 2D biplane DSA projections did not reveal any thrombus or vessel truncation, leaving the cause of hypoperfusion unclear. Given the diagnostic uncertainty, intra-procedural 3D RA was performed.

Results: 3D RA revealed a discrete occlusion in the superior division of the M2 segment that was not visible on conventional 2D projections. This enabled precise microcatheter navigation and successful clot retrieval. The patient showed subsequent clinical improvement post-procedure.

Conclusion: This case highlights the diagnostic value of 3D RA in mechanical thrombectomy when conventional DSA is inconclusive. While not part of the standard thrombectomy workflow, selective use of 3D RA can provide essential visualization of distal or anatomically complex occlusions. Its selective use may improve procedural accuracy and patient outcomes in carefully chosen cases.

A-078

Flow diversion with adjunctive coil embolization for fetal posterior communicating aneurysms

Category: Cerebral Aneurysm

Primary Author

Yukiko Enomoto

Gifu University Hospital Japan

Co-Author

Yusuke Egashira

Gifu University Hospital

Hirofumi Matsubara

Gifu University Hospital

Tsuyoshi Izumo

Gifu University Graduate School of Medicine

Background and Purpose: Flow Diversion (FD) can be challenging to treat fetal posterior communicating aneurysm (FPCoA). Besides FD alone, there are several adjunctive techniques including adjunctive coiling, but their efficacy remains unclear. We retrospectively review our experience with FD combined with adjunctive coiling for FPCoA.

Materials and Methods: We included 9 patients (mean age 74yr, 8 females, 6 ruptured aneurysms) with FPCoA underwent FD with coiling in our institution from October 1, 2017, to March 31, 2025,. Coil embolization was performed to achieve partial or more occlusion while simultaneously to protect the neck where the fetal Pcom bifurcates. Demographic, clinical, treatment details, and imaging data were extracted and reviewed.

Results: All 9 patients had ipsilateral P1, and underwent FD with coiling as a single session (3), as a 2nd stage treatment for ruptured aneurysms (3), or as additional treatment for recurrent aneurysms after coiling (3). The median aneurysm size was 14 (12-14) and neck was 7.5 (7.2-8) mm. The median length of deployed FD was 7 (25-28) mm, including one patient using 2 FDs. The Raymond-Roy occlusion classification just after procedure was II (5), IIIa (3) and IIIb (1), and O’Kelly-Marotta grade B (5) and C (4). On follow-up magnetic resonance or catheter angiography during follow-up periods (median 25 months), Roy-Raymond class I occlusion was not achieved in any patients, whereas class II occlusion, which was considered as satisfactory angiographic result, was achieved in 7 patients (77.8%) and persistent class III occlusion in 2 patients (14.5%). All patients had complete patency of the fetal Pcom. One ruptured FPCoA patient under persistent class III occlusion required additional treatment 9 months after FD. Additional dome and Pcom embolization with coils via retrograde approach from ipsilateral P1 resulted in a minor postoperative stroke, but the occlusion status has remained stable for 1 year after this procedure. Except one patient presented with severe subarachnoid hemorrhage, 8 patients had satisfactory clinical outcomes.

Conclusion: In our case series, FD with coiling showed acceptable clinical and angiographic outcomes. Because the residual neck was stable without regrowth in 8 of 9 cases, Raymond-Roy class II occlusion could be an appropriate procedural goal for FD in FPCoA.

A-079

Efficacy and Outcomes of Accero Intracranial Braided Stent in Wide-Neck Bifurcation Aneurysms: A Single-Center Experience

Category: Cerebral Aneurysm

Primary Author

Ahmed Albaqshi

Asan Medical centre Saudi Arabia

Co-Author

Deok Hee Lee

Asan Medical centre

Yunsun Song

Asan Medical centre

Boseong Kwon

Asan Medical centre

Background and Purpose: To evaluate the efficacy and safety of the Accero braided stent in the endovascular management of wide-neck bifurcation intracranial aneurysms, based on a single-center experience.

Materials and Methods: We retrospectively reviewed 125 consecutive patients treated with Accero intracranial stents between 2022 and 2024. A total of 87 patients met the inclusion criteria, which required aneurysms to be of initial presentation, originate from major intracranial bifurcation sites—such as the anterior cerebral artery (ACA), anterior communicating artery (ACoA), fetal-type posterior communicating artery (PCoA), internal carotid artery (ICA), middle cerebral artery (MCA), or top of the basilar artery (TOBA)—and to exhibit a wide-neck configuration (neck size ≥4 mm or dome-to-neck ratio <2). Procedures were performed using the Accero braided stent with adjunctive coiling, employing the Pull-and-Push technique for better coverage of the neck. Follow-up imaging was performed immediately post-procedure and at approximately six months, utilizing magnetic resonance angiography (MRA) with time-of-flight (TOF), fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted imaging (DWI) sequences. Additionally, a blinded 3D rotational angiography review will be performed by three independent interventional neuroradiologists to assess preferred treatment strategies (single stent, Y-stent, WEB device, or other).

Results: The mean patient age was 61.7 years, with 72.4% being female. All aneurysms were saccular, with 93.1% located in the anterior circulation, and the mean maximum aneurysm diameter was 4.9 mm. Complete aneurysm occlusion was achieved in 97.7% of cases on follow-up imaging. DWI revealed asymptomatic microembolic lesions in 16.1% of patients. One case demonstrated recurrence at follow-up imaging, and one intraprocedural hemorrhage occurred without resulting neurological deficit. No symptomatic thromboembolic complications were observed.

Conclusion: The Accero braided stent provides a highly effective and safe option for treating wide-neck bifurcation aneurysms using a single stent. Its high occlusion rates, minimal complication profile, and favorable follow-up imaging outcomes support its integration into routine neurointerventional practice.

A-081

Carotid artery stenting in elderly patients over 80 years old

Category: Other Head and Neck Pathologies

Primary Author

Kotaro Ueda

Kameda Medical Center Japan

Co-Author

-

Background and Purpose: The prevalence of carotid artery stenosis increases with age, and opportunities for treatment of carotid artery stenosis in elderly patients are increasing in the current super-aged society in Japan. Based on the results of several RCTs, Japanese stroke society guideline recommend carotid endarterectomy (CEA) rather than carotid artery stenting (CAS) for elderly patients who should undergo revascularization therapy. But CAS, which can be performed under local anesthesia, is often chosen in the daily practice. We investigated the efficacy and safety of CAS for elderly patients over 80 years old.

Materials and Methods: All cases in which CAS was performed on elderly pa- tients aged 80 years or older from April 2015 to March 2023 in Funabashi Municipal Medical Center (my pre- vious workplace) were included in the study, exclud- ing emergency CAS performed following mechanical thrombectomy. To assess safety and efficacy, we ret- rospectively compared with patients aged 80 years or older who underwent CEA during the same period .

Results: The mean age of the CAS group was 82.9 years, and 30 patients (90.9%) were male. Symptomatic lesions were 24 (68.6%), and the mean stenosis rate (NASCET method) was 69.5%. All patients were treated with an embolic protection device, and closed cell stents were placed in 31 lesions (88.5%) with a 100% procedural success rate. Symptomatic ischemic complications in the acute postoperative period occurred in 3 lesions (8.5%), but all symptoms were transient, and none of them decreased the modified Rankin Scale at discharge. Hyperperfusion on image occurred in 4 lesions (11.4%), 2 of which (5.7%) were symptomatic. During a mean follow-up of 23.9 months, late symptomatic intracranial lesions occurred in 1 lesion (2.9%), but were thought to be caused by an ipsilateral intracranial stenotic lesion. During the same period, CEA was performed in 16 lesions in patients over 80 years of age, and there were no significant differences in the incidence of symptomatic cerebral infarction, hyperperfusion syndrome, or other complications between the CAS and CEA groups.

Conclusion: CAS for elderly patients over 80 years of age was successful in all cases, with no permanent sequelae or complications caused by the treatment.

A-082

When the Spine Deceives: Acute Paraparesis as the Initial Manifestation of a Cranial dAVF

Category: Dural Arteriovenous Fistulae

Primary Author

Nutpisit Nawaratthara

Ramathibodi hospital, Mahidol University Thailand

Co-Author

Chai Kobkitsuksakul

Ramathibodi hospital, Mahidol University

Background and Purpose: Cranial dural arteriovenous fistulas (dAVFs) commonly manifest with symptoms related to intracranial hypertension or hemorrhage. Myelopathy due to venous congestion is more frequently associated with spinal dAVFs, while the occurrence of spinal cord symptoms originating from cranial dAVFs are remarkably infrequent. We report a case of cranial dAVF that initially presented with acute paraparesis with bowel and bladder dysfunction, clinically mimicking a spinal pathology. This case emphasizes the necessity of considering cranial vascular lesions in the differential diagnosis of acute myelopathy and aims to enhance awareness of this rare yet treatable entity.

Results: A 38-year-old male presented with acute onset paraparesis, constipation, and urinary retention, without back pain. Examination revealed bilateral lower limb weakness, diminished sensation below the T10 level, and reduced anal tone. Magnetic resonance imaging (MRI) of the spine revealed prominent intrathecal flow voids extending from the craniocervical junction to the conus medullaris, along with T2 hyperintensity within the cervical spinal cord, findings consistent with venous congestive myelopathy. Subsequent brain MRI, magnetic resonance angiography (MRA), and magnetic resonance venography (MRV) demonstrated an an aggressive dural arteriovenous fistula (dAVF) at the left transverse-sigmoid sinus junction, characterized by cortical venous reflux and cerebellar venous infarctions. Digital subtraction angiography (DSA) confirmed a high-grade dAVF supplied by multiple branches of the left external carotid artery, with venous drainage into the spinal perimedullary veins. Endovascular intervention included transvenous coil embolization of the left inferior vermian vein followed by Onyx embolization of the left transverse sinus. Post-procedural angiography demonstrated obliteration of spinal venous drainage, with residual slow-flow shunting via the jugular bulb. The patient exhibited rapid clinical improvement, achieving ambulation within several days. At the 3-month follow-up assessment, spinal MRI confirmed the resolution of abnormal intrathecal vessels and spinal cord congestion. Clinically, the patient had achieved full neurological recovery.

Conclusion: Cranial dAVFs with spinal venous drainage may manifest as acute myelopathy, mimicking intrinsic spinal cord pathologies. Timely recognition and prompt endovascular intervention are crucial to mitigate the risk of irreversible neurological sequelae. This case underscores the importance of considering cranial vascular anomalies in the differential diagnosis of patients presenting with unexplained spinal cord dysfunction.

A-083

Longitudinal braid stability of Surpass Evolve® Flow diverter in the aspect of Fish-Mouthing deformation

Category: Cerebral Aneurysm

Primary Author

Minu Nahm

Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, South Korea

Co-Author

Jung-Jae Kim

Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea

Keun Young Park

Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea

Yong Bae Kim

Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea

Hyun Jin Han

Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea

Background and Purpose: Flow diverters (FDs) are increasingly utilized as promising tools in the management of complex cerebral aneurysms, achieving acceptable rates of morbidity and mortality. Fish-mouthing (FM), a convergence of focal FD end, without in-stent stenosis or intimal hyperplasia, has been observed during follow-up. While its clinical impact remains uncertain, FM may potentially contribute to thromboembolic events and therefore calls for attention. This study aimed to evaluate the incidence, longitudinal progress, and clinical relevance of FM following FD deployment.

Materials and Methods: We retrospectively reviewed 123 patients who underwent FD implantation using a single Surpass Evolve device (Stryker Neurovascular, Kalamazoo, MI, USA) for the treatment of cerebral aneurysms at a single institution. Postoperative and one-month follow-up skull X-rays were systematically compared to assess the presence of FM, defined as a >25% reduction in the distal end diameter of the device based on the recommendations endorsed by the societies. Additional six-month and one-year follow-up skull X-rays and computed tomography (CT) angiography were evaluated to monitor the longitudinal progression or newly developed FM. Patient demographics, aneurysm characteristics and procedure-related factors were assessed to identify potential risk factors for FM. In addition, procedure- related complications were collected to investigate the clinical relevance of FM.

Results: Of the 123 patients, 99 patients (with 118 aneurysms) completed postoperative and one-month imaging follow-up. Most aneurysms (91.5%) were located in the internal carotid artery(ICA), with a mean size of 10.819±5.164 mm and saccular type(79.7%). FM was identified in 17 patients (17.17%), with a mean distal diameter reduction of 30.4% and an absolute decrease of 1.165±0.29 mm. For FM, sixteen cases (94.12%) occurred within the first month, and one developed at one year. No thromboembolic complications were observed. Notably, 81.25% of FM cases resolved spontaneously within one year.

Conclusion: Surpass Evolve showed incidence of FM (17.17%), predominantly occurring within the first month. Despite this, FM appeared to be a self-limiting phenomenon, without associated thromboembolic complication. Therefore, in cases where FM is iden- tified during follow-up, careful imaging follow-up may be considered.

A-084

Outcome of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Single-Center Retrospective Study

Category: Other Neurovascular and Rare Diseases

Primary Author

Pipat Pattanapipitpaisal

Ramathibodi Hospital Thailand

Co-Author

Mungkorn Apirakkan

Ramathibodi Hospital

Background and Purpose: Chronic subdural hematoma (CSDH) recurs in up to one-third of patients following burr-hole evacuation. Middle meningeal artery embolization (MMAE) is a minimally invasive alternative or adjunctive treatment, though high-quality evidence in Asian populations remains limited. We evaluated the effectiveness, safety, and predictors of treatment failure of MMAE for CSDH at a tertiary center in Thailand.

Materials and Methods: We retrospectively reviewed adult patients who underwent MMAE for CSDH in our hospital between 2022 to 2024. The primary outcome was treatment failure, defined as hematoma progression requiring rescue surgery within 3 months. Secondary outcomes included radiological failure (<50% reduction in hematoma thickness on 3-month CT) and pro- cedure-related complications. Univariable and multivariable logistic regression analyses were performed to identify predictors of failure. Receiver operating characteristic (ROC) analysis determined the optimal pre-operative hematoma thickness cutoff associated with treatment failure.

Results: 47 embolizations were performed in 34 patients (mean age 75 ± 9 years; 64% male). Technical success was 100%. Non-disabling complications occurred in 3 cases (6%). Treatment failure occurred in 6 embolizations (12.8%), and radiological failure in 9 of 41 evaluable cases (22%). Median hematoma thickness decreased from 11.0 mm (IQR 9.1–13.2) to 2.9 mm (IQR 0–5.2), representing a median 74% reduction; complete resolution occurred in 44% of embolizations. On multivariable analysis, pre-operative hematoma thickness was the only independent predictor of failure (OR 1.27/mm; p=0.045). ROC analysis identified 13.24 mm as the optimal cutoff (AUC 0.83; sensitivity and specificity both 83%).

Conclusion: Our results align with international studies reporting MMAE failure rates of 5–15%. The higher radiological failure rate observed in our cohort may relate to a greater proportion of elderly patients, larger baseline hematoma volume, or concurrent antiplatelet therapy use. Larger hematomas likely reflect more mature membranes, microvascular proliferation, recurrent microbleeding, and chronic inflammation that may be less responsive to embolization alone. Patients with pre-operative thickness ≥13 mm may benefit from early surgery, hybrid treatment, or intensified postoperative surveillance. MMAE demonstrates strong efficacy, low complication rates, and promising potential for reducing surgical burden in appropriately selected patients. Further multicenter prospective studies are warranted to validate these findings and optimize patient selection criteria in diverse clinical populations.

A-085

Mechanical thrombectomy for acute ischemic stroke: The response time of code stroke protocol in jakarta comprehensive stroke center

Category: Acute Ischemic Stroke

Primary Author

Priyambodo Permana

Department of Neurosurgery, Faculty of Medicine, Universitas Indonesia, dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia

Prof. dr. IGNG Ngoerah General Hospital, Bali, Indonesia

Department of Epidemiology, Faculty of Public Health, Indonesia

Co-Author

Sudarto Ronoatmodjo

Department of Epidemiology, Faculty of Public Health, Universitas Indonesia, Depok, West Java, Indonesia

Background and Purpose: Stroke is the leading cause of death and disability in Indonesia. Time is brain, and golden period of time should be achieved to expect better outcome for stroke patients, and it is now become one of the flagship program of our Ministry of Health. Code stroke protocol include multidisciplinary team management of acute stroke patients to achieve best standardize treatment and fast response according to recent guidelines, with door to CT, needle and groin puncture should be in 20, 60, and 90 minutes respectively. This study aims to showed our response time in management of acute ischemic stroke after implementing code stroke protocol

Materials and Methods: This is a retrospective multicentered study in two comprehensive stroke centers in Jakarta, from 2017 to 2024. All acute ischemic stroke patients that eligible for mechanical thrombectomy were included, and some were excluded due to unavailable data.

Results: Of 244 patients that received mechanical thrombectomy, 145 were included in this study. Most were male (62.1%), with age mean 57±11.1 years old. Patients mostly came with moderate NIHSS score (5-15; 57.1%) and the median time of onset was 168 (range 25-1080) minutes. The median of door-to-CT was 9 minutes. Thrombolysis were given in 41.4% patients and the mean time of onset to needle was 4.34±1.9 hours. The door-to-needle and groin-puncture median time were 68 and 299 minutes respectively.

Conclusion: From our study it showed that our citizen is aware enough of stroke and they received the CT examination and thrombolysis fast enough. However, mechanical thrombectomy still did not even close to the goal time. There were many obstacles we have either from the patient or the hospital system, such as the decision time of the patients’ family, the availability of the devices, anesthesia tolerance, intensive care or stroke unit availability, and the coverage of the medical insurance of the procedure. Code stroke is important for creating an established system in the hospital. Our hospital already established the system for more than 5 years, yet there is still several obstacles need to overcome.

A-087

Transvenous Approach in a Dural Arteriovenous Fistula with High-Risk External Carotid-to-Ophthalmic Anastomosis: A Case Report

Category: Dural Arteriovenous Fistulae

Primary Author

Vita Kusuma Rahmawati

Department of Neurology, dr. Haryoto General Hospital, Lumajang; and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia. Indonesia

Co-Author

Achmad Firdaus Sani

Department of Neurology, Universitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia.

Dedy Kurniawan

Department of Neurology, Universitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia.

Faishol Hamdani

Department of Neurology, Bangil General Hospital, Pasuruan; and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia.

Muh. Wildan Yahya

Department of Neurology, Kabupaten Kediri General Hospital, Kediri; and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia.

Shakir Husain Hakim

Stroke and Neurointervention Foundation (SNIF); New Delhi, India.

Background and Purpose: Dural arteriovenous fistulas (DAVFs) are abnormal shunts between dural arteries and venous sinuses or cortical veins, often presenting with nonspecific symptoms. Selecting an appropriate treatment strategy is critical to prevent neurological complications.

Results: A 54-year-old woman with long-standing type 2 diabetes presented with pulsatile tinnitus, unilateral headache, and blurred vision in her left eye. Brain Magnetic Resonance Imaging (MRI) revealed chronic ischemic lesions and a left-sided DAVF. Cerebral Digital subtraction angiography (DSA) confirmed the fistula: arterial supply arose from the internal maxillary and ascending pharyngeal branches of the external carotid artery (ECA), with venous drainage into the left superior petrosal sinus and pterygoid plexus. DSA also revealed an unusual vascular variant the left ophthalmic artery originated from the internal maxillary artery. This skull base ECA-ophthalmic anastomosis poses a high risk if trans-arterial embolization is attempted. The presence of multiple small feeders made curative transarterial embolization unlikely. Therefore, a transvenous approach was selected. A microcatheter was advanced through the internal jugular vein to the affected sinus, and detachable coils were deployed until complete occlusion of the fistula was achieved. Post-embolization DSA showed blush of the ophthalmic artery on the ECA after venous occlusion, revealed clearer visualization of the ophthalmic artery variation. DAVFs with dangerous ECA–ICA anastomoses and multifocal feeders may be most safely and definitively treated from the venous side.

Conclusion: This case underscores the value of meticulous angiographic analysis and highlights transvenous coil embolization as an effective alternative when trans-arterial cure is unlikely or unsafe.

A-088

Impact of Oophorectomy in the Hashimoto Model for Rat Cerebral Aneurysm Induction: Comparative Study of Surgical Success and Aneurysm-Related Events Incidence

Category: Cerebral Aneurysm

Primary Author

Sungbin Hwang

Seoul Asan Medical Center South Korea

Co-Author

Sungbin Hwang

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Yeonsoo Kim

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Mihyeon Kim

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Yunsun Song

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Deok Hee Lee

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Background and Purpose: The Hashimoto rat cerebral aneurysm model consistently shows high incidence rates of both ruptured and unruptured aneurysms. It is suggested that aneurysm formation rates increase further in oophorectomized rats. This study aimed to compare surgical success and the incidence of aneurysm-related events (ARE) between oophorectomy (OVX) and non-oophorectomy (Non-OVX) rats to determine whether the Hashimoto model remains stable in oophorectomized rats.

Materials and Methods: Female Sprague-Dawley rats were divided into Non-OVX (n=15) and OVX groups (n=10). Both groups underwent left common carotid artery ligation and right renal artery ligation, followed by a high-salt and BAPN mixed diet. OVX rats underwent bilateral oophorectomy at 6 weeks and received identical treatment from 8 weeks. Survival for over one week post-surgery was defined as surgical success. ARE, defined as aneurysm formation with or without subarachnoid hemorrhage (SAH), was monitored using MR imaging at 0, 1, 4, 8, and 12 weeks post-surgery. Vascular corrosion casting and SEM assessed aneurysm formation. In cases of early death, cranial autopsy and histological studies identified ARE. Statistical comparisons between groups were made using Fisher’s exact test.

Results: Surgical success rates were similar between the Non-OVX group (86%, 13/15) and the OVX group (90%, 9/10; p=0.99). ARE incidence was 61.5% (8/13) in Non-OVX (2 ruptured aneurysms, 1 SAH without visible aneurysm, 5 unruptured aneurysms) and 77.8% (7/9) in OVX (1 ruptured aneurysm, 2 SAH without visible aneurysm, 4 unruptured aneurysms), with no statistically significant difference (p=0.64).

Conclusion: In this preliminary study, although limited by small sample sizes, no significant differences were observed between OVX and Non-OVX groups regarding surgical success and ARE incidence. However, observed differences in ARE patterns suggest further research with larger sample sizes is necessary to fully evaluate the potential impact of oophorectomy on cerebral aneurysm formation in the Hashimoto rat model.

A-090

Complete Angiographic Resolution of Intracranial Mycotic Aneurysms Following Conservative Therapy: A Case Report

Category: Cerebral Aneurysm

Primary Author

Muh. Wildan Yahya

Department of Neurology, Kabupaten Kediri General Hospital, and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia Indonesia

Co-Author

Achmad Firdaus Sani

Neurointervention Division, Department of Neurology, Universitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Dedy Kurniawan

Neurointervention Division, Department of Neurology, Universitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Vita Kusuma Rahmawati

Department of Neurology, Dr. Haryoto Lumajang General Hospital, and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Faishol Hamdani

Department of Neurology, Bangil General Hospital, and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Shakir Husain Hakim

Stroke and Neurointervention Foundation (SNIF), New Delhi, India

Background and Purpose: Intracranial mycotic aneurysms (IMAs) are rare vascular lesions frequently associated with infective endocarditis (IE). Management strategies vary depending on aneurysm size, location, and rupture status. Although surgical or endovascular interventions are often preferred, conservative medical management with antibiotics has shown success in selected cases. However, complete angiographic resolution remains a rare outcome.

Results: We present a case of a 57-year-old male with a history of diabetes and valvular heart disease who developed multiple IMAs. The patient presented with sudden left-sided weakness, facial asymmetry, and slurred speech, with preserved consciousness. MRI revealed a hyperacute right parietal intracerebral hemorrhage (approximately 63 mL) due to a ruptured aneurysm at the M2–M3 segment of the right middle cerebral artery. Cerebral angiography confirmed two closely adjacent mycotic aneurysms in the superior trunk of the right MCA. Transthoracic and transesophageal echocardiography identified mobile vegetations on the anterior and posterior mitral leaflets, fulfilling criteria for IE. The patient underwent urgent craniotomy for hematoma evacuation but was managed conservatively for the aneurysms. Following the diagnosis of IE, intravenous ampicillin (2 g three times daily) was administered for 42 days, followed by oral erythromycin (250 mg twice daily) for six months. Additional medical therapies included antiepileptics for seizure control and agents for glycemic control and cardiovascular management. A follow-up cerebral angiography performed six months after antibiotic therapy demonstrated complete angiographic resolution of the aneurysms, with no residual vascular abnormalities. Clinically, the patient exhibited marked neurological improvement, with intact consciousness (GCS 15), resolution of headaches, slight residual facial palsy, and improved left-sided motor strength (5/4+). Sensory and autonomic functions remained normal.

Conclusion: This report demonstrates that, under carefully selected conditions, intracranial mycotic aneurysms (IMAs) can achieve complete clinical and angiographic resolution with conservative antibiotic therapy. Successful outcomes depend on appropriate patient selection, considering aneurysm morphology, location, clinical stability, and radiological follow-up. These findings contribute to growing evidence that conservative management may represent an effective therapeutic strategy, with serial imaging essential to guide individualized treatment decisions.

A-091

A case of intracranial mycotic aneu- rysm recurrence after endovascular treatment followed by spontaneous occlusion

Category: Cerebral Aneurysm

Primary Author

Yasutoshi Akasaki

Juntendo University Nerima Hospital Japan

Co-Author

Joji Tokugawa

Juntendo University Nerima Hospital

Chinastu Kasuga

Koshigaya Municipal Hospital

Kentaro Kudou

Koshigaya Municipal Hospital

Hiroshi Hasegawa

Koshigaya Municipal Hospital

Background and Purpose: Spontaneous occlusion of cerebral aneurysms has been reported in cases such as ruptured, giant, or dissecting aneurysms. However, reports regarding intracranial mycotic aneurysms (IMAs) are limited. In particular, cases in which the aneurysm recurred after endovascular treatment before spontaneously occluding within a few days are extremely rare. We treated a patient with an IMA located in the proximal posterior cerebral artery (PCA), which recurred soon after endovascular treatment followed by sponta- neous occlusion.

Results: The patient was a 38-year-old man who presented with subarachnoid hemorrhage (WFNS Grade II). He had a history of Streptococcus salivarius bacteremia and dental caries three months earlier. Initial workup on admission revealed Staphylococcus haemolyticus bacteremia, and bacterial meningitis. A dissecting an- eurysm was detected in the P1 segment of the right PCA, and coil embolization was performed the fol- lowing day. On day 7, a small recurrence in the neck of the aneurysm was observed. On day 45, an en- largement of the recurrence was observed along with coil compaction and looping at the aneurysm neck, and an additional elective endovascular surgery was planned. However, preoperative imaging revealed spontaneous occlusion of the aneurysm, and the ad- ditional treatment was abandoned. No recurrence of the aneurysm was observed thereafter, and the pa- tient was transferred to a subacute rehabilitation unit with a modified Rankin Scale score of 1 on day 70.

Conclusion: IMAs are considered to progress through four phases: (phase I) lodging of infective emboli in the parent ar- tery, (II) aneurysm formation, (III) rupture in some cas- es, and (IV) thrombosis and spontaneous healing of the vessel. Furthermore, spontaneous thrombosis of aneurysms may be promoted by several factors such as reduction of intra-aneurysmal flow, vasospasm, high aneurysm sac volume to orifice ratio, endothe- lial injury due to inflammation, and/or use of contrast material. In this case, inflammation due to infection, together with coil compaction, likely induced endothe- lial injury and reduced intra-aneurysmal flow. These changes, combined with the natural healing of the parent artery, may have led to spontaneous thrombo- sis of the aneurysm. Further study of similar cases is essential for a better understanding of the underlying pathogenesis.

A-092

Glue Embolization of a Ruptured Posterior Thalamoperforating Artery Aneurysm within the Artery of Percheron Territory

Category: Cerebral Aneurysm

Primary Author

Nabha Tangchitphredanonth

Ramathibodi Hospital Thailand

Co-Author

Mungkorn Apirakkan

Ramathibodi Hospital

Background and Purpose: Thalamoperforator aneurysms are extremely rare, particularly within the territory of the artery of Percheron (AOP)—a solitary perforator that supplies bilateral paramedian thalami and rostral midbrain. Due to its terminal nature and lack of collateral support, treat- ment of AOP aneurysms carries substantial risk of ischemic complications. However, conservative management poses greater danger, given the high risk of rebleeding and poor neurologic outcomes. We report a rare and technically demanding case of ruptured posterior thalamoperforating artery aneurysm successfully treated with endovascular glue embolization in an elderly patient.

Results: An 81-year-old woman with hypertension and valvular heart disease presented with sudden-onset severe headache and nausea. Non-contrast CT revealed diffuse subarachnoid and intraventricular hemorrhage. CT angiography demonstrated multiple aneurysms with contrast extravasation at the interpeduncular cistern. Digital subtraction angiography confirmed a ruptured 2.4 × 4.5 mm perforator aneurysm arising from the left P1 segment of the PCA an AOP variant in the setting of cranial fusion of the basilar apex. Another right posterior communicating artery (PComA) aneurysm was also identified. A microcatheter was navigated into the perforator, and 0.6 mL of 30% glue was injected, achieving complete aneurysm obliteration with proximal arterial occlusion. Balloon-assisted coiling of the right PComA aneurysm followed. After extensive multidisciplinary consultation and detailed explanation of procedural risks, ischemic consequences, and long-term disability, the patient’s relatives provided informed consent for intervention. Post-procedurally, the patient developed right medial thalamic infarction. She was discharged with a modified Rankin Scale (mRS) score of 4, improving to mRS 3 at 2-month follow-up with structured neurorehabilitation.

Conclusion: Asymmetrical cranial fusion of the basilar apex often results in unilateral P1 dominance, predisposing the AOP to arise from a single trunk and increasing vulnerability to hemodynamic stress, aneurysm formation, and rupture. Although small, perforator aneurysms have a reported rebleeding rate of up to 40% and mortality approaching 70% without treatment. Endovascular embolization is generally favored when feasible. The unilateral infarction may reflect anatomical variation, dominant perfusion laterality, or localized embolic spread. Delayed recovery likely reflects the functional complexity of thalamic structures, combined with reduced neuroplastic potential in elderly individuals. Early diagnosis, patient-family engagement, and individualized planning are essential for optimiz- ing outcomes.

A-093

From Support to Stress: Aneurysm Formation Through Chronic Hemodynamic Load of Collateral Flow

Category: Cerebral Aneurysm

Primary Author

Putu Yudhi Nusartha

Department of Neurology, Universitas Mulawarman, Abdoel Wahab Sjahranie Hospital, and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia, Indonesia

Co-Author

Achmad Firdaus Sani

Neurointervention Division, Department of Neurology, Universitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Dedy Kurniawan

Neurointervention Division, Department of Neurology, Universitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Intan Sudarmadi

Department of Neurology Dr. Mohamad Saleh Hospital, and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Soni Azhar Pribadi

Department of Neurology, Ngudi Waluyo Wlingi General Hospital, and Fellowship of Vascular Neurointervention Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Shakir Husain Hakim

Stroke and Neurointervention Foundation (SNIF), New Delhi, India

Background and Purpose: Vascular remodelling following craniofacial tumour resection involving vascular manipulation can lead to long-standing hemodynamic alterations. While most intracranial aneurysms arise from congenital wall defects or bifurcation-related stress, acquired arterial rerouting may also play a significant role in aneurysm pathophysiology. We report a rare case of mid-basilar artery aneurysm formation likely resulting from chronic collateral flow burden following nasopharyngeal angiofibroma surgery performed in adolescence.

Results: A 47-year-old male presented with progressive right hemifacial spasm, numbness, slurred speech, and spasticity. Digital subtraction angiography (DSA) demonstrated a large, wide-necked sidewall aneu- rysm at the mid-basilar artery (15.5 mm × 9.9 mm; neck 8.3 mm). The patient had undergone craniofa- cial tumour resection in adolescence, likely involving ligation of external carotid artery feeders. Over sub- sequent years, collateral pathways formed, rerouting significant arterial inflow through the left vertebral artery to maintain external carotid territory perfusion. This chronic hemodynamic redirection resulted in dominant left vertebral flow, confirmed by substantial caliber asymmetry between the left and right verte- bral arteries, contributing to continuous shear stress on the basilar artery wall and aneurysm formation. A dual femoral access strategy was used: partial coiling was performed directly within the mid-basilar aneu- rysm via left femoral artery access using a 45-degree microcatheter and 9 mm × 31 cm coil. Subsequently, a flow diverter (4 mm × 23 mm) was deployed across the aneurysm neck in the basilar artery via right fem- oral artery access, using a straight-tip microcatheter and distal access catheter positioned in the vertebral artery. This hybrid approach was selected to reduce mass effect while promoting gradual aneurysm exclu- sion through flow remodelling.

Conclusion: This case demonstrates that collateral circulation, though initially compensatory, may chronically impose pathological flow patterns leading to delayed aneurysm development. Understanding the vascular consequences of prior craniofacial tumour surgery is critical when evaluating atypical aneurysm locations. Recognition of post-surgical hemodynamic consequences is crucial for diagnosing atypical aneurysm etiologies and planning individualised neurointerventional treatment.

A-094

Hemodynamic Remodeling of the Circle of Willis in a Rat Unilateral Carotid Ligation Model: Longitudinal MR Angiographic Observation

Category: Cerebral Aneurysm

Primary Author

Yeon Soo Kim

Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Seoul, Republic of Korea, South Korea

Co-Author

Sungbin Hwang

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, Seoul, Republic of Korea

Mi Hyeon Kim

Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Seoul, Republic of Korea

Boseong Kwon

Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea, Seoul, Republic of Korea

Yunsun Song

Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea, Seoul, Republic of Korea

Deok Hee Lee

Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine., Seoul, Republic of Korea

Background and Purpose: Vascular remodeling of the circle of Willis (COW) due to altered hemodynamics plays a central role in aneurysm vulnerability. Such remodeling is segment dependent and often asymmetrical, yet its spatiotemporal patterns remain poorly charac- terized in vivo. This study aimed to longitudinally quantify morphologic changes in the COW using high-resolution MR angiography in a hypertensive rat model and to compare remodeling patterns between surgery and control groups.

Materials and Methods: An 81-year-old woman with hypertension and valvular heart disease presented with sudden-onset severe Thirteen rats underwent left CCA and right RA ligation with a high-salt diet and BAPN (surgery group), while six rats received sham surgery (control group). Serial 7T MR angiography was performed at baseline and at 1, 4, and 12 weeks. Arterial diameter and tortuosity index (TI) were assessed in major COW segments. Linear mixed models evaluated time-group interactions and side-specific effects. Control animals were scanned at baseline, week 4, and week 12 to match the surgical timeline.

Results: The surgery group exhibited dynamic and asymmetric vascular remodeling not observed in controls. Significant group × time interaction was found in Right A1 (p=0.030), Right A2 (p=0.037), BA (p=0.034), Right PCOM (p=0.034), and Left PCOM (p=0.001). Right ICA showed the most pronounced remodeling (group effect p=1.1e-5, interaction p<0.001). Left PCA showed early dilation followed by regression, while right ICA and A1 progressively dilated. TI increased significantly in the surgery group (Right: p=0.019, Left: p=0.011), with greater between-group differences over time (p<0.001 and p=0.035). Segment-specific post-hoc analyses confirmed significant diameter or tortuosity increases compared to D0 as early as W1, including the left PCA (p = 0.0067), basilar artery (p < 0.0001), and right TI (p = 0.0156). These findings suggest that major remodeling was already underway by week 1 and largely stabilized by week 4.

Conclusion: Longitudinal MR angiography enables detailed evaluation of COW remodeling. Significant differences between surgical and control groups highlight the role of altered flow in shaping vascular structure. Most remodeling occurred by week 4, demonstrating the utility of MR imaging in capturing early hemodynamic adaptation.

A-095

Diagnostic Limits of High-Resolution MR Angiography for the Visualization of Intracranial Aneurysms in a Rat Model Background and Purpose

Category: Cerebral Aneurysm

Primary Author

Yeon Soo Kim

Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Seoul, Republic of Korea, South Korea

Co-Author

Sungbin Hwang

Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, Seoul, Republic of Korea

Mi Hyeon Kim

Biomedical Engineering Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Seoul, Republic of Korea

Boseong Kwon

Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea, Seoul, Republic of Korea

Yunsun Song

Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea, Seoul, Republic of Korea

Deok Hee Lee

Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine., Seoul, Republic of Korea

Background and Purpose: MR angiography (MRA) offers a non-invasive modality for detecting vascular pathology, yet its sensitivity to early or small aneurysm-related events remains uncertain. This study aimed to delineate the detection boundary of high-resolution MRA by comparing imaging findings with pathology-confirmed outcomes in a hypertensive rat model.

Materials and Methods: Thirteen rats underwent unilateral carotid and renal artery ligation with BAPN to induce aneurysm-prone hemodynamics. Serial 7T MRA was performed at 0, 1, 4, and 12 weeks, and findings were compared to scanning electron microscopy (SEM) after corrosion casting. Each rat was classified into true positive (TP), false positive (FP), false negative (FN), and true neg- ative (TN) groups based on SEM and MR. Lesions detected and undetected by MRA were further evaluated by segmental location and morphology.

Results: Among 13 rats, SEM confirmed aneurysm-related events in 8. MR imaging identified 9 rats as positive, yielding 6 TP, 3 FP, 2 FN, and 2 TN. MRA sensitivity and specificity were 75.0% and 40.0%. The average diameter of MR-detected aneurysms (n=5) was 0.57 mm, with lesions most frequently located at the left P1 (n=3), right MCA (n=1), and A1-OF junction (n=1). Of these, 3 lesions confirmed on both MR and SEM had a larger average size of 0.74 mm. In contrast, the average diameter of SEM-confirmed aneurysms was 0.26 mm. False negatives tended to be smaller and morphologically subtle. They were located at the left A1-OF origin (n=2), right MCA (n=2), and right A2 (n=1), suggesting that even lesions in typical sites may escape detection if their contrast or shape is insufficient. False positives appeared at the left P1 and right A1–A2 junction, possibly reflecting signal irregularities or borderline variants unconfirmed by SEM.

Conclusion: This study demonstrates the diagnostic boundaries of high-resolution MRA for aneurysm-related events in vivo. Understanding what MRA can and cannot detect especially relative to lesion size and location is key to interpreting preclinical imaging. Integration with pathology remains critical. As an early experience, this work sets the stage for future expansion to broader animal models, including ovariectomized rats to study hormonal effects.

A-098

Predicting Cerebral Aneurysm Recurrence After Coil Embolization: A Novel Deep Learning Approach Using Time-of-Flight MR Angiography

Category: Cerebral Aneurysm

Primary Author

Shoko Fujii

Department of Endovascular Surgery, Institute of Science Tokyo, Tokyo, Japan, Japan

Co-Author

Kyohei Fujita

Department of Endovascular Surgery, Institute of Science Tokyo, Tokyo, Japan

Satoru Takahashi

Department of Endovascular Surgery, Institute of Science Tokyo, Tokyo, Japan

Sakyo Hirai

Department of Endovascular Surgery, Institute of Science Tokyo, Tokyo, Japan

Kazutaka Sumita

Department of Endovascular Surgery, Institute of Science Tokyo, Tokyo, Japan

Background and Purpose: Recurrence following coil embolization remains a major clinical challenge in the management of cerebral aneurysms, often requiring prolonged follow-up and potential retreatment. While several risk factors have been proposed, these existing factors lack sufficient generalizability. This study aimed to develop a deep learning–based model using Time-of-Flight MR Angiography (TOF-MRA) as noninvasive imaging to improve the prediction of aneurysm recurrence.

Materials and Methods: This retrospective multicenter study analyzed 154 patients with coil-embolized unruptured cerebral aneurysms across five stroke centers. Three prediction models were developed: a logistic regression model, a neural network model using clinical data, and a combined deep learning model incorporating clinical and imaging data from three-dimensional reconstructed TOF-MRA. The combined model was created in two versions: one exclusively with pre-operative images and the other using pre- and post-operative images. Image preprocessing involved standardized reconstruction of seven 3D views per case from TOF-MRA, followed by conversion to 2D inputs. The models were evaluated using leave-one-out cross-validation to assess the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity. Gradient-weighted Class Activation Mapping (Grad-CAM) was applied for interpretability.

Results: Among the 154 cases, 46 (29.9%) showed recurrence. The combined model using pre-and post-operative TOF-MRA images showed the highest discriminative performance (AUC, 0.75) and sensitivity (0.74), demonstrating a superior ability to distinguish recurrence. The version using only pre-operative images showed high accuracy (0.76) and specificity (0.88) but a lower AUC. When the sensitivity was fixed at 0.80, the combined model using both imaging time points maintained balanced performance (accuracy 0.66, specificity 0.60). Grad-CAM highlighted relevant anatomical features in both pre- and post-treatment images, providing visual interpretability.

Conclusion: This study demonstrated the potential of integrating TOF-MRA images into AI-driven models to enhance aneurysm recurrence prediction after coil embolization. The superior performance of the combined model, particularly when using pre- and post-operative images, suggests the potential for more precise, personalized predictions of recurrence risk.

A-099

Early Clinical Experience with Surpass ELITE flow diverters: Technical and Clinical Considerations

Category: Cerebral Aneurysm

Primary Author

Jung-Jae Kim

Yonsei University Severance Hospital South Korea

Co-Author

Minwoo Nam

Yonsei University Severance Hospital

Suzy Yoon

Yonsei University Severance Hospital

Hyun Jin Han

Yonsei University Severance Hospital

Yong Bae Kim

Yonsei University Severance Hospital

Keun Young Park

Yonsei University Severance Hospital

Background and Purpose: The Surpass ELITE (SE) flow diverters are designed to promote better wall apposition based on the broader braid angle than previous Surpass EVOLVE flow diverters. Furthermore, a novel surface modification is applied to a 64-wire conduit of single-layered cobalt-chromium alloy. This study aims to provide a comprehensive description of the technical feasibility and intra- and peri-operative safety of SE flow diverters.

Materials and Methods: A retrospective analysis was conducted on twenty-seven consecutive cases of intracranial aneurysm treatment with SE flow diverters. A comprehensive review and analysis was conducted on the properties of SE flow diverters, intraprocedural thromboembolic complications, early (<30 days) neurological complications, and imaging/clinical follow-up data.

Results: A total of 28 SE flow diverters were utilized in the treatment of 37 intracranial aneurysms (average maximal diameter 10.12 ± 0.96 mm), affecting 27 patients (22 female, average age 57 years). All patients were treated with one SE flow diverter, with the exception of one patient in whom telescopic stenting with two SE flow diverters was utilized to bail out the dislodgement of the initial stent into the aneurysm. During the procedure, successful deployment of SE flow diverters was achieved without any suboptimal opening of the distal end. Coil was used as an adjunct in 3 patients (11.1%) and balloon-angioplasty was performed in 14 patients (51.9%) to promote wall-apposition. One patient treated for vertebral artery dissecting aneurysm exhibited symptoms of motor weakness immediately following the procedure. However, the patient had recovered as a modified Rankin scale score 1 on discharge. Another patient with a symptomatic ICA aneurysm over 20 mm developed diplopia one week after the procedure. On short-term follow-up (< 6 months), eight of nine aneurysms assessable on the imaging were completely obliterated.

Conclusion: Preliminary findings might indicate the credible performance of SE flow diverters for intracranial aneurysms, enhancing wall apposition and precise delivery, attributable to their evolved design and properties.

A-100

Endovascular Treatment for Stenosis of the Petro-Cavernous Segment of the Internal Carotid Artery

Category: Acute Ischemic Stroke

Primary Author

Jung-Hwan Oh

Department of Neurology, Jeju National University Hospital, Jeju National University College of Medicine, South Korea

Co-Author

Joong-Goo Kim

Department of Neurology, Jeju National University Hospital, Jeju

National University College of Medicine

Background and Purpose: Stent placement is an effective treatment option for patients with stenosis of the petro-cavernous segment of the internal carotid artery (ICA). However, the periprocedural risks and anatomical considerations remain unclear. This study aims to evaluate periprocedural complications and hazardous anatomical features associated with symptomatic petro-cavernous ICA stenosis, with a focus on characteristics specific to each occlusion mechanism.

Materials and Methods: This study retrospectively analyzed periprocedural complications in 14 patients who underwent balloon angioplasty and stent placement for symptomatic severe stenosis (>70%) of the petro-cavernous segment of the ICA. Patients were enrolled consecutively at a tertiary care hospital between March 1, 2018, and August 30, 2022. All patients had ischemic stroke confirmed by magnetic resonance angiography in association with petro-cavernous ICA stenosis and received endovascular treatment.

Results: The follow-up period ranged from 8 to 36 months. Restenosis was observed in 6 patients (42.8%). The overall morbidity rate was 14.2%, and the mortality rate was 7.1%. One patient died during follow-up due to a recurrent stroke and intractable in-stent thrombosis.

Conclusion: Balloon angioplasty and stent placement are acceptable treatment options in patients with symptomatic petro-cavernous ICA stenosis. However, since the petro-cavernous segment ICA is a tortuous site and there may be a risk of plaque protrusion or rupture associated with surrounding structures such as bone or ligament, a careful approach is required when performing the endovascular treatment.

A-101

Retrospective Evaluation of Intravenous Cone Beam CT Angiography as a Follow-up Tool Post Flow Diverter Treatment: Assessment of Image Quality, Artifact, and Treatment Outcomes

Category: Cerebral Aneurysm

Primary Author

Suppaluk Anukulsampan

Fellowship at Siriraj hospital Thailand

Co-Author

Boonrerk Sangpetngam

Siriraj hospital

Anchalee Churojana

Siriraj hospital

Pattarawit Withayasuk

Siriraj hospital

Ekawut Chankaew

Siriraj hospital

Thaweesak Aurboonyawat

Siriraj hospital

Background and Purpose: Flow diverter therapy treats intracranial aneurysms by altering blood flow and promoting vessel wall remodeling. While DSA is the gold standard for post-treatment follow-up, it is invasive. This study evaluates IV CBCTA as a noninvasive alternative, focusing on image quality, artifacts, and treatment outcomes like device apposition, stenosis, and aneurysm morphology.

Materials and Methods: This retrospective study included 23 patients with intracranial aneurysms who were treated with various types of FDS and scheduled for follow-up with IV CBCTA. Image quality was assessed with quantitative analysis (SNR, CNR), and treatment outcomes (wall apposition, stenosis, aneurysm changes) were evaluated using descriptive statistics.

Results: Image quality, with SNR ranging from 2.77 to 26.48 (mean±SD: 7.83±5.06) and CNR ranging from 1.88 to 24.77 (mean±SD: 6.25±4.82), was assessed. Motion artifacts were present in 17.4% of patients. Regarding treatment outcomes, aneurysm occlusion was achieved in 43.48% of patients, with 34.78% showing a decrease in residual aneurysm size. Stable residuals were noted in 17.39%, and regrowth was observed in 4.35%. Wall apposition was deemed good in 86.95% of patients, with minor issues such as malapposition (4.35%) and a floating stent (4.35%) observed in a few cases. Mild intimal hyperplasia was present in 26.09% of cases, with no hyperplasia found in the remaining 73.91%. No patients experienced vascular occlusion or stenosis, and 100% of vascular branches were patent.

Conclusion: Intravenous cone-beam CT angiography shows promising potential for the effective evaluation of vascular status following the placement of intracranial flow diverters. The flow diverter devices used to treat intracranial aneurysms appear to be effective for long-term placement, demonstrating favorable morphological outcomes and an absence of delayed complications.

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Pioneering Advances in Posterior Circulation Acute Ischemic Stroke: Insights from Two Stroke Centers in Indonesia on Mechanical Thrombectomy

Category: Acute Ischemic Stroke

Primary Author

Yoga Arif Syah Hidayat

Faculty of Medicine, Universitas Indonesia Indonesia

Co-Author

Yoga Arif Syah Hidayat

Department of Neurosurgery, Faculty of Medicine, Universitas Indonesia-dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia

Zharifah Fauziyyah Nafisah

Department of Neurosurgery, Faculty of Medicine, Universitas Indonesia-dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia

Affan Priyambodo Permana

Department of Neurosurgery, Faculty of Medicine, Universitas In- donesia-dr. Cipto Mangunkusumo National General Hospital, Ja- karta, Indonesia. Prof. dr. IGNG Ngoerah General Hospital, Bali, Indonesia

Renindra Ananda Aman

Department of Neurosurgery, Faculty of Medicine, Universitas Indonesia-dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia

Setyo Widi Nugroho

Department of Neurosurgery, Faculty of Medicine, Universitas Indonesia-dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia

Background and Purpose: Stroke is the leading cause of mortality and disability in Indonesia. Comprising 20–25% of ischemic strokes, posterior circulation acute ischemic stroke (PCAIS) is one of its most severe forms, with subtle clinical man- ifestations complicating early diagnosis. PCAIS affects critical regions which govern vital functions such as consciousness and motor coordination. These factors, exacerbated by Indonesia’s sociogeographic challenges, highlight the urgent need for optimized thrombectomy interventions to improve patient prognosis.

Materials and Methods: This retrospective multicenter study, conducted at two stroke centers in Jakarta from 2017 to 2024, included all eligible PCAIS patients for mechanical thrombectomy.

Results: Eleven patients participated in this study, with a predominance of males (90.9%) and a mean age of 54.8 ± 9.5 years. The patients presented with a median symptom onset of 255 (122-1080) minutes and NIHSS score of 15 (10-25). The location of infarct was mostly in basillar artery (54.5%) and vertebral artery (36.4%). Stent retriever was used in 54.5% of patients, with good recanalization (mTICI 2B-3) in 63.6% of the total. The majority of patients (72.7%) died during hospitalization. Of the survivors, only one achieved a favorable 90-day modified Rankin score.

Conclusion: The majority of patients with PCAIS experienced poor outcomes, consistent with some prior studies, though remains debated. Notably, two exceptional cases demonstrated favorable functional outcomes, potentially due to robust collateral circulation, highlighting an area for further exploration. These findings emphasize the critical need for precise patient selection and a careful evaluation of the risk-benefit balance in implementing thrombectomy, setting the stage for future studies to refine treatment strategies.

A-104

The clinical outcomes for the endovascular treatment of ruptured internal carotid artery blood blister-like aneurysm in 7 cases

Category: Cerebral Aneurysm

Primary Author

Shinsuke Sato

St Luke’s International Hospital, Department of Neurosurgery Japan

Co-Author

Yasunari Niimi

St Luke’s International Hospital, Department of Neuroendovascu- lar therapy

Mituki Itou

St Luke’s International Hospital, Department of Neurosurgery

Kazuki Kushi

St Luke’s International Hospital, Department of Neurosurgery

Tatuki Mochizuki

St Luke’s International Hospital, Department of Neurosurgery

Tatuya Inoue

St Luke’s International Hospital, Department of Neurosurgery

Background and Purpose: Ruptured Blood blister-like aneurysms (BBAs) usually arise from the anterior walls of the internal carotid artery. Several surgical and endovascular techniques have been described for the treatment of these aneurysms, however, there is still no consensus on the best technique or method. We studied the endovascular management of ruptured BBAs patients. 7 patients with ruptured BBAs located of the internal carotid artery were studied. Endovascular therapy was adopted as the first-line therapy. Patients’ aneurysmal characteristics, progression status, aneurysm occlusion on follow-up angiography, and modified Rankin Scale (mRS) score were recorded.

Results: A total of 7 patients (2 women and 4 men) with the mean age of 50 years were included in this study. The WFNS grade were 1-2 and 4-5 in 5 and 2 patients. As initial treatment, 5 patients were treated with stent-assisted coiling (SAC). 2 patients were treated with Enterprise2 stent and FRED, each. Perioperative ischemic complication in one patient was observed. No patients suffered from rebleeding. Retreatments were performed in 4 patients. Additional coiling was performed in one patient and FRED were deployed in 4 patients. Perioperative ischemic complication in additional treatments were not observed. Follow up results were 4 patients in complete occlusion and 2 patients in partial occlusion. Clinical data revealed at discharge mRS scores of 0-2, 3, and 4 in 5,1,and 1 patient, respectively. The mRS score at the final follow-up was 0-2 for all patients.

Conclusion: The multi-selection of endovascular treatment of ruptured internal carotid artery blood blister-like aneurysms is more important for the prognosis of the patient’s condition and prevention of rebleeding.

A-106

Efficacy of mechanical thrombectomy supported by Radiologic technologists under telemedicine supervision system

Category: Acute Ischemic Stroke

Primary Author

Mitsuyoshi Watanabe

Jikei University School of Medicine Japan

Co-Author

Hiroyuki Suzuki

Fuji City General Hospital

Shun Okawa

Jikei University School of Medicine

Chisato Kato

Fuji City General Hospital

Toshihiro Ishibashi

Jikei University School of Medicine

Yuichi Murayama

Jikei University School of Medicine

Background and Purpose: Mechanical thrombectomy (MT) is standard therapy for acute ischemic stroke. However, MT requires skilled endovascular surgeons 24/7/365, which is not achieved by many hospitals especially in rural areas and developing countries. We have radiologic technologists to assist MT and utilize telemedicine system for the mentor to supervise MT procedure, and investigated its safety and efficacy to solve this problem.

Materials and Methods: One or two neurosurgical residents with trained radiologic technologists performed MT (RTMT group) under supervision of board-certified endovascular surgeon through telemedicine system. Radiologic technologists received hands-on training of MT beforehand, and performed preparation and cleanup of devices and control of angiography table during MT procedure. The mentor was on live-streaming telemedicine system through smartphone/tablet/PC application (JOIN; Allm Inc, Tokyo, Japan) to supervise their procedure. The angiographical and clinical outcomes were compared with conventional MT cases (CMT group).

Results: All cases completed MT without on-site support of senior surgeons. There was no difference in Puncture- to-reperfusion time (RMT 64min vs CMT 70min, p=0.576), TICI>=2b (76.9% vs 85.7%, p=0.749) and number of passes (2.1 vs 2.0, p=0.925). Median mRS was 5 and 4, respectively. Telemedicine supervision also showed no difference in PTR (TMT 82min vs 64min, p=0.182), TICI>=2b (76.9% vs 85.7%, p=0.749) and number of passes (2.1 vs 2.0, p=0.925), and median mRS was 5 and 4, respectively.

Conclusion: Assistance by Radiologic technologists and telemedicine supervision are safe, and let young endovascular surgeons concentrate on MT procedure. This can be one of the practical solutions for the insufficiency of trained endovascular surgeons.

A-107

Image diagnosis for intracranial atherosclerotic disease (ICAD)-related LVO, Usefulness of “insula cortex sign”

Category: Acute Ischemic Stroke

Primary Author

Masataka Takeuchi

Seisho hospital Japan

Co-Author

Kazuma Tsuto

Seisho hospital

Yu Shimizu

Seisho hospital

Tadateru Goto

Seisho hospital

Background and Purpose: Preoperative imaging in acute cerebral main artery occlusive disease is important for treatment indication and device selection. Preoperative imaging can easily identify the extent of ischemia and the site of the occluded vessel, but may be difficult to diagnose the disease type. Susceptibility vessel sign (SVS) on MRI (T2*) is considered to be specific for cardiogenic disease, but is also seen in some cases of acute occlusion in Intracranial atherosclerotic disease (ICAD).

Results: In this study, we report a retrospective analysis of insula cortex negative sign in patients with middle cerebral artery occlusion (M1) and its possible role in the diagnosis of ICAD acute occlusion. Early ischemic changes in the insular cortex were significantly different in 417 (84.2%) cardiogenic and 3 (4.2%) ICAD cases. There was also a high rate of specificity and sensitivity with negative insular cortex at ICAD related M1 occlusion.

Conclusion: In the acute phase of M1 occlusion, the presence or absence of ischemic changes in the insular cortex is useful in the diagnosis of the disease type.

A-108

Dangerous anastomosis; Mechanisms of ophthalmic manifestation

Category: Others

Primary Author

Dong Joon Kim

Severance Hospital/Yonsei University College of Medicine South Korea

Co-Author

Haram Joo

Yonsei University College of Medicine

Byung Moon Kim

Yonsei University College of Medicine

Background and Purpose: Dangerous anastomoses are potential connections between the extracranial and intracranial circulation. Understanding this anatomy is fundamental for safe and effective treatment in neurointerventional procedures. The purpose of this study is to describe the mechanism of ophthalmic manifestations of the dangerous anastomoses during neurointerventional procedures.

Results: Monoocular partial/complete blindness occurred in 5 patients in association with coil embolization of an aneurysm (n=1), liquid embolization of DAVFs (n=2), post trans-sphenoidal surgery bleeding embolization (n=1), and tumor embolization (n=1). The mechanisms of the dangerous anastomosis manifestation included pressured opening & migration of the liquid embolic material into the potential channel (n=2), vasospasm related glue reflux (n=1), reflux of PVA embolic material (n=1), and thrombus formation due to flow competition within the anastomotic channels after coil embolization of an ophthalmic aneurysm (n=1). The monocular blindness symptoms were permanent (n=3) and transient (n=2).

Conclusion: Various different mechanisms may partake in the clinical manifestation of the dangerous anastomosis in the orbital area. Understanding these mechanisms with a comprehensive knowledge of the anatomy may prevent unwarranted complications associated with the neurointerventional procedures.

A-109

Woven endoBridge embolization for intracranial aneurysms: single center experiences in South Korea

Category: Cerebral Aneurysm

Primary Author

Keun Young Park

Severance Hospital, Yonsei University College of Medicine South Korea

Co-Author

Hyun Jin Han

Severance Hospital, Yonsei University College of Medicine

Jung-Jae Kim

Severance Hospital, Yonsei University College of Medicine

Yong Bae Kim

Severance Hospital, Yonsei University College of Medicine

Background and Purpose: Endovascular treatment for intracranial bifurcation aneurysm with wide-neck remains challenging and is prone to complications. Currently, the Woven Endobridge (WEB) is widely utilized for intracranial aneurysm treatment. However, the safety and efficacy of this approach requires conclusive establishment. This presentation aims to evaluate clinical and radiological outcomes of intracranial aneurysm embolization using the WEB device.

Materials and Methods: From August 2021 to April 2025, 281 consecutive patients (male:female = 108:173, mean age 63.9) with 286 aneurysms underwent treatment with the WEB device in single center. Demographic characteristics, procedural details and complications, clinical outcomes, and one-year radiological findings were retrospectively reviewed. Aneurysm occlusion was assessed using the modified WEB Occlusion Scale (WOS). Moreover, propensity score matching was conducted to compare WEB embolization with stent-assisted coiling (SAC).

Results: The cohort comprised 23 ruptured and 263 unruptured aneurysms, including 5 cases of recurrent aneurysms (4 post-coiling and one post-clipping). Mean aneurysm diameter was 5.66 mm (range: 2.75–13.67). The most common locations were anterior communicating artery (Acom, 41.3%), followed by middle cerebral artery bifurcation (35.3%), basilar apex (18.9%), and internal carotid artery (ICA) bifurcation (4.5%). Except for one intraprocedural rupture, all aneurysms were successfully treated with the WEB device (technical success rate: 99.6%). WEB size adjustments were needed in 69 cases (24.1%), and assisting techniques were required in 39 cases (13.6%). Procedure-related complications occurred in 19 cases (6.7%), including 4 transient ischemic attacks (TIA), 4 strokes, 4 intraprocedural ruptures, 3 puncture site complications, and 4 iatrogenic parent artery injuries. Permanent morbidity and mortality rates were 0.7% (two in mRS 1) and 0.3%, respectively. One-year angiographic follow-up was available for 144 cases (50.3%), with a complete occlusion rate (WOS A and B) of 78.5%. There were 3 recurrent aneurysms, which were successfully treated by additional coiling (0.2%). Comparing the SAC, the 6-month clinical and radiological outcomes of unruptured intracranial aneurysms treated with WEB were comparable. WEB has advantages over SAC, including reduced fluoroscopy time (p < .001) and avoidance of dual antiplatelet therapy.

Conclusion: WEB is a safe and effective alternative to SAC for the treatment of wide-neck bifurcation aneurysms with high occlusion rates and low complication risks.

A-110

Safety, efficacy and cost effectiveness of Middle Meningeal Artery (MMA) Embolization for Chronic Subdural Hematoma: A single-centre experience

Category: Others

Primary Author

Tien Meng Cheong

National Neuroscience Institute Singapore

Co-Author

Rambert, Guan Mou Wee

National Neuroscience Institute

Tze Phei Kee

National Neuroscience Institute

Wickly Lee

National Neuroscience Institute

Background and Purpose: Middle meningeal artery (MMA) embolization has emerged as a promising treatment for chronic subdural hematomas (cSDH), with randomized trials (mostly using liquid embolic) supporting its efficacy as both a standalone and adjunctive therapy. However, surgical drainage remains a lower-cost alternative, raising questions about the cost-effectiveness of MMA embolization—particularly with liquid embolic agents. We present our single-center experience of MMA embolization using both particles and liquid embolic, evaluating its safety, efficacy, and cost-effectiveness.

Results: Thirty patients were included (mean age 76.4 years; 96.7% male). The most common presenting symptom was neurological deficits (43.3%), followed by gait instability/falls (30%). At presentation, 20% were on anticoagulation and 36.6% on antiplatelet therapy. Particulate embolics (Embosphere) were used in 90% of cases, with transfemoral access employed in 66%. Mean cSDH thickness reduction was 1 cm (SD 0.6 cm), and midline shift improved by 0.5 cm. Treatment failure occurred in one patient (3.3%), requiring salvage burr-hole drainage. We had 1 case of retained catheter while using liquid embolic agent with no long lasting consequences. No other procedural complications, post procedural neurological deficits or mortalities were observed. In our institute, the average cost of consumables was S$ 1,800 for particulate embolic versus S$ 4,477 for liquid embolic. The cost savings associated with particles arise from their lower price compared to liquid embolics (S$ 380 vs. S$ 1600), as well as reduced micro-catheter usage - unlike liquid embolic, which require a micro-catheter change following injection of each branch.

Conclusion: In our cohort, MMA embolization using particles was safe, effective, and significantly more cost-effective than liquid embolics. These findings support the adoption of particle-based embolization as a financially sustainable alternative in cSDH management.

A-112

The clinical strategy and outcomes for brain arteriovenous malformation using multimodal therapy.

Category: Cerebral Arteriovenous Malformation

Primary Author

Shinsuke Sato

St Luke’s International Hospital, Department of neurosurgery Japan

Co-Author

Yasunari Niimi

St Luke’s International Hospital, Department of neuroendvascular therapy

Mituki Itou

St Luke’s International Hospital, Department of neurosurgery

Kazuki Kushi

St Luke’s International Hospital, Department of neurosurgery

Tatuki Mochizuki

St Luke’s International Hospital, Department of neurosurgery

Tatuya Inoue

St Luke’s International Hospital, Department of neurosurgery

Background and Purpose: The management of brain AVM(bAVM) relies on multidisciplinary discussions that lead to patient- specific strategies based on patient preferences, local expertise, and experience in referral centers.

Materials and Methods: We examined the indications, efficacy, and outcomes of patients receiving multimodal therapy for bAVM management, considering endovascular treatment as the first choice. This retrospective analysis included 48 patients who were treated between 2015 and 2025.

Results: 13 patients with frontal AVM, 4 patients with temporal AVM, 7 patients with parietal AVM, 8 patients with occipital AVM, and 16 patients with others. 40 (83.3%) patients presented with hemorrhage. 5 (10.4%) patients presented with intractable epilepsy. 1 patient presented with enlargement of varix. 2 patients were astmptomatic. Spetzler Martin (SM) grading 1,2,3,and 4 were 8, 15, 19, and 7cases, respectively. Endovascular treatment was mainly performed in 32/48, 6/48, and 8/48 patients using NBCA, Onyx, and NBCA/Onyx, respectively. Target embolization for aneurysm-related hemorrhage was performed in two cases. One of the two patients who underwent embolization required direct carotid puncture. Complications related to embolization occurred in 3patients.(2cases of SAH. 1 case of IVH). No permanent neurological deficits associated with embolization were observed. Hemorrhage after the initial treatment occurred in two cases of pial AVF (one after endovascular treatment and one after craniotomy) and one case of parietal lobe AVM with intraventricular hemorrhage (after endovascular treatment and gamma knife therapy).

Conclusion: Further research is necessary to evaluate the treatments for bAVM, including safe devascularized embolization. Multimodal therapy for bAVM with open surgery, appropriate embolization, and stereotactic radiosurgery has shown good outcomes according to patient-specific strategies in our series.

A-113

Pixels with a Purpose: Diagnosing Mycotic Aneurysm From Odontogenic Infective Endocarditis. Radiologic Clues in an Acute Stroke Activation.

Category: Cerebral Aneurysm

Primary Author

Yuh Yang Leong

Hospital Canselor Tuanku Muhriz UKM Malaysia

Co-Author

Mohamad Izzat Arslan Che Ros

Department of Radiology, Faculty of Medicine, Hospital Canselor Tuanku Muhriz Ukm

Isa Azzaki Zainal

Department of Radiology, Hospital Pakar Kanak Kanak Ukm

Shuang Yee Ho

Department of Radiology, Hospital Canselor Tuanku Muhriz Ukm

Bee Hong Soon

Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Hospital Canselor Tuanku Muhriz Ukm

Farizal Fadzil

Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Hospital Canselor, Tuanku Muhriz Ukm

Background and Purpose: Stroke activations often reveal more than just ischemia. Rarely, a ruptured mycotic aneurysm secondary to infective endocarditis (IE) presents as a haemorrhagic stroke mimic. This case highlights the power of holistic imaging interpretation in unveiling a covert source of sepsis, culminating in a life-saving diagnosis

Results: A 49-year-old man with no prior medical history presented with acute left upper limb weakness, triggering an acute stroke activation. Initial non-contrast CT brain revealed diffuse bilateral subarachnoid haemorrhage (SAH), prompting the search of the source. CT angiography (CTA) identified a subtle enhancing dot in the right high frontal parasagittal region. Digital subtraction angiography confirmed a tiny distal anterior cerebral artery aneurysm with features highly suggestive of a ruptured mycotic aneurysm. A broader review of systemic imaging yielded vital diagnostic clues. Chest radiograph incidentally showed marked cardiomegaly with left atrial enlargement, raising suspicion for underlying cardiac pathology WITH mitral valve involvement. Further scrutiny of CTA bone window revealed subtle dental periapical lucencies consistent with dental abscesses — an unusual but critical finding. The constellation of findings suggested a path of progression from periapical dental infection to bacteremia, leading to infective endocarditis and septic embolism, culminating in a ruptured mycotic aneurysm. The patient underwent targeted glue embolisation of the aneurysm using NBCA via a Magic microcatheter, with no new neurologic sequelae. Subsequent echocardiography confirmed mitral valve vegetations with severe regurgitation, prompting urgent mitral valve replacement (MVR) after completion of intravenous antibiotics for 6 weeks. Dental evaluation confirmed ongoing periapical abscesses, and dental clearance was completed thereafter.

Conclusion: This case exemplifies the diagnostic value of meticulous, multimodal imaging review in stroke mimic presentations. A small periapical abscess, an enlarged cardiac silhouette, and a punctate vascular anomaly — when connected — led to the rare diagnosis of ruptured mycotic aneurysm secondary to infective endocarditis from dental sepsis. Early recognition enabled timely neurointervention, cardiac surgery, and infection source control. We advocate for a systematic, whole-body approach in acute neurovascular imaging, especially when atypical findings arise.

A-114

Bilateral Middle Meningeal Arteries Arising from the Ophthalmic Arteries with Absence of the Anterior Communicating Artery in Ruptured Dissecting Distal Anterior Cerebral Artery Aneurysm: An Extremely Rare Case

Category: Other Neurovascular and Rare Diseases

Primary Author

Soni Azhar Pribadi

Department of Neurology, Ngudi Waluyo Wlingi General Hospital, and Fellowship of Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Co-Author

Achmad Firdaus Sani

Neurointervention Division, Department of Neurology, Univer- sitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Dedy Kurniawan

Neurointervention Division, Department of Neurology, Univer- sitas Airlangga, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Intan Sudarmadi

Department of Neurology Dr. Mohamad Saleh Hospital, and Fellowship in Vascular Neurointervention, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Putu Yudhi Nusartha

Department of Neurology, Universitas Mulawarman, Abdoel Wa- hab Sjahranie Hospital, and Fellowship in Vascular Neurointerven- tion, Dr. Soetomo Academic Medical Center Hospital, Surabaya, Indonesia

Shakir Husain Hakim

Stroke and Neurointervention Foundation (SNIF), New Delhi, India.

Background and Purpose: The middle meningeal artery (MMA) typically branches from the maxillary artery, entering the cranial through the foramen spinosum. The MMA that origin from the ophthalmic artery is exceptionally rare and is usually unilateral. The anterior communicating artery (AComA) completes the anterior segment of the Circle of Willis; its absence is an uncommon variant that may influence hemodynamic and aneurysm formation. Aneurysms of the Distal Anterior Cerebral Artery (DACA) are also rare, constituting about 6% (range, 2%–9%) of all intracranial aneurysms. This report aims to present an exceptionally rare neurovascular anomaly.

Results: A 53-year-old male presented with subarachnoid hemorrhage (SAH) due to a dissecting DACA aneurysm. Cerebral angiography revealed bilateral MMAs originating anomalously from the ophthalmic arteries instead of the typical maxillary arteries. Computed Tomography also demonstrated hypoplastic foramina spinosum bilaterally. Embryologically, the MMA derives from the stapedial artery, which originates from the second aortic arch. During development, the stapedial artery regresses as its branches are taken over by the external carotid artery system. The maxillary branch of the stapedial artery anastomoses with the maxillary artery to form the definitive MMA, which typically enters the skull through the foramen spinosum. Embryologically, agenesis of the AComA represents failure of the anterior cerebral artery plexus to fuse during the fifth gestational week. Aneurysms of the DACA are rare. Variations of the A2–A4 circulation are common. These developmental variants of the DACA may be associated with an increased propensity for DACA aneurysm formation, particularly at the bifurcation of the pericallosal and callosomarginal arteries. As the result, this case present an exceptionally rare neurovascular anomaly.

Conclusion: This case highlights a combination of three neurovascular variant: bilateral middle meningeal arteries arising from the ophthalmic arteries, absence of the anterior communicating artery and distal anterior cerebral artery. Combination of these three neurovascular anatomy in one patient is extremely rare case. Understanding such rare variants is crucial for accurate cerebral angiographic interpretation and further neurointervention management.

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Late-Onset Vascular Occlusion After Direct Puncture of a Carotid Prosthetic Graft for Endovascular Access

Category: Others

Primary Author

Reo Kawaguchi

Kushiro Memorial Hospital Japan

Co-Author

Shigeru Miyachi

Aichi medical university

Background and Purpose: In neuroendovascular treatment, choosing an appropriate vascular access route is critical for procedural success and safety. In patients with a history of aortic arch replacement, conventional access via the femoral, radial, or brachial arteries is often technically unfeasible due to graft-related vascular friction. In such cases, direct carotid puncture may serve as a viable alternative. In this case, we report a case of delayed vascular occlusion caused by direct puncture of a carotid artery prosthetic graft.

Results: A 78-year-old woman presented with dizziness and memory impairment. MRI showed a large aneurysm (14.7 × 12.0 mm) at the C4 segment of the right internal carotid artery (ICA). She had previously undergone total arch replacement for Stanford type A aortic dissection. Due to severe arch deformation, traditional access routes were deemed unsuitable. Direct puncture of the cervical prosthetic graft was performed under ultrasound guidance, followed by successful deployment of a flow diverter. No immediate complications occurred. At 3-month follow-up, MRI showed shrinkage of the aneurysm. At 6-month follow-up, cervical ultrasound and intracranial CTA revealed occlusion of the graft at the puncture site. However, the patient remained asymptomatic without new neurological deficits.

Conclusion: Direct puncture of prosthetic grafts carries an estimated complication rate of 10–20%, including pseudoaneurysm formation, anastomotic disruption, thromboembolism, and infection. To our knowledge, there are no previous reports specifically describing direct carotid access via a prosthetic graft. Although vascular occlusion following such puncture is rare, this case highlights the need for caution and long- term follow-up. Direct carotid puncture through a prosthetic graft can be a technically feasible solution when conventional access is unavailable. However, it carries distinct risks, including delayed vascular occlusion. Careful procedural planning and ongoing follow-up are essential for ensuring patient safety in such cases.

A-116

The usefulness of 3D venography in the treatment of dural arteriovenous fistulae

Category: Others

Primary Author

Rie Aoki

Tokai University School of Medicine, Tokyo Japan

Co-Author

Azusa Sunaga

Tokai university hospital Tokyo

Masaaki Imai

Tokai university hospital Tokyo

Hideki Atsumi

Tokai university hospital Tokyo

Shinri Oda

Tokai university hospital Tokyo

Masami Shimoda

Tokai university hospital Tokyo

Background and Purpose: In the treatment of dural arteriovenous fistulae (dAVF), the venous structure can be complex in some cases, making it difficult to determine the location of the shunt, the areas that should and should not be embolized, and the approach route. we experienced some cases of dAVF in which the structure was clarified by performing three-dimensional(3D) venography, allowing for safer and more accurate treatment.

Results: This study included 12 dAVF cases treated using 3D venography between April 2014 and April 2025. All of 8 cavernous sinus (CS) dAVF cases are symptomatic with occluded inferior petrosal sinus (IPS). 2 HC- dAVF cases are borden type 2. one case had two shunt points, CS and HC. One case had two shunt points, HC and transeverse sinus. The catheter was successfully guided through the occluded IPS in all cases. And the average time of catheterization to the shunt point from the IPS is 13 minutes 13 seconds. There is no complication related to venography and procedures. In 11 cases , the shunt disappeared com- pletely. In one case, shunt point slightly remained after the procedure. But symptoms disappeared.

Conclusion: It is necessary to analyze the angioarchitecture of the lesion using 3D images to understand accurately the reflux point and approach route to the reflux point. 3D venography (under compression of the jugular vein) is useful to identify the connection of occluded IPS and can show the precise anatomy of the connection between the shunt and veins that should not be embolized.

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Carotid total occlusion: hints and approaches to achieve better recanalized rate

Category: Acute Ischemic Stroke

Primary Author

Huy Nguyen

SIS General Hospital Vietnam

Co-Author

-

Background and Purpose: Carotid total occlusion causes acute ischemic stroke, which is hardly located the lesion in the tortuous intracranial segments or the ostium of the internal carotid artery (ICA). Here we proposed some criteria for more accurate recognition of ostium ICA as the culprit lesion and techniques to achieve a better recanalized rate.

Materials and Methods: This case series included patients admitted to SIS Hospital because of total occlusion of ICA leading to acute ischemic stroke from Jan 2023 to Jun 2024. All patients were performed diagnostic digital subtraction angiography (DSA) in the first week of hospitalization and endovascular carotid stenting after 2 weeks from the onset. Primary outcomes were the technical success rate, periprocedural ischemic and hemorrhagic rates. Secondary outcomes included rates of recurrence ischemic episodes and mortality.

Results: This case series included patients admitted to SIS Hospital because of total occlusion of ICA leading to acute ischemic stroke from Jan 2023 to Jun 2024. All patients were performed diagnostic digital subtraction angiography (DSA) in the first week of hospitalization and endovascular carotid stenting after 2 weeks from the onset. Primary outcomes were the technical success rate, periprocedural ischemic and hemorrhagic rates. Secondary outcomes included rates of recurrence ischemic episodes and mortality.

Conclusion: Recognition of ostium ICA occlusion and proposed coaxial intervention system can be indications of high-rate successful carotid stenting for acute ischemic stroke caused by ICA total occlusion

A-118

Top of Basilar Artery Occlusion Syndrome

Category: Acute Ischemic Stroke

Primary Author

Linh Duong Hoang

Can Tho S.I.S. General Hospital Vietnam

Co-Author

-

Background and Purpose: Acute top-of-the-basilar artery occlusion is rare and clinically quite severe. Accurate diagnosis of this lesion necessitates careful clinical evaluation and imaging, particularly brain MRI, which is extremely important. Mechanical thrombectomy seems appropriate for treating these cases. However, clinical data is few. We investigated whether mechanical thrombectomy in top-of-the-basilar artery occlusion improved clinical outcome by modified Rankin Scale (mRS) score within 3 months after the procedure.

Materials and Methods: This was a retrospective analysis of patients with acute top-of-the-basilar artery occlusion who were treated with mechanical thrombectomy between June 2021 and January 2024 at our hospital. Clinical, neuroimaging, procedural, outcome, and complications data were collected. Primary outcomes included the rate of good outcomes (mRS ≤ 2) at 3-month follow-up.

Results: Twenty-two patients who underwent mechanical thrombectomy in top-of-the- basilar artery occlusion were enrolled in the study. All patients were achieved the successful recanalization (mTICI ≥ 2b). Seventeen patients (77.3%) were recanalized using the ADAPT technique, and five patients (22.8%) needed a combination of the ADAPT technique and stent retrievers. Eighteen patients (81.8%) had a good outcome (mRS ≤ 2) at 3 months, and no patient underwent decompressive craniectomy.

Conclusion: Our study suggests that despite the small series with top-of-the-basilar artery occlusion, mechanical thrombectomy might be safe, has a high success rate, and is related to a good outcome. However, the diagnosis may be missed if not considered carefully. In particular, MRI is necessary and important for the accurate diagnosis of top -of-the-basilar artery occlusion.

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Rescue carotid stenting in tandem occlusions: 5 years’ experience from a comprehensive stroke center

Category: Acute Ischemic Stroke

Primary Author

Duc Nguyen Minh

SIS General Hospital Vietnam

Co-Author

-

Background and Purpose: Rescue carotid stenting has recently been provided as an additional treatment followed by mechanical thrombectomy in patients with tandem occlusions of the anterior circulation. Nevertheless, few available data support the benefits of this treatment in Asia. We hypothesized that this treatment would be associated with improved postprocedural clinical outcomes.

Materials and Methods: We retrospectively analyzed patients who underwent rescue carotid stenting for tandem occlusions of the anterior circulation between December 2020 and May 2024 at Can Tho S.I.S. General Hospital. Clinical, neuroimaging, procedural, and complication data were collected. Primary outcomes included the rate of good outcomes with the modified Rankin Scale (mRS) ≤ 2 at 3-month follow-up.

Results: Ninety patients with tandem occlusions of the anterior circulation who underwent rescue carotid stenting were included, all of whom achieved successful recanalization. Among the 80 cases with the distal-to- proximal approach, diagnostic- Dotter was used in 85 %. Fifty-three patients (58.9 %) had good outcomes, and six patients (6.7 %) experienced parenchymal hemorrhage type II, which was associated with death (mRS 6) after the procedure.

Conclusion: Placement of rescue carotid stenting in tandem occlusions was associated with improved clinical outcomes, without increasing symptomatic intracranial hemorrhage