Interventional Neuroradiology

Interventional Neuroradiology (INR) is an international journal devoted to a highly sub-specialized field with international editorial board members and a representative journal through which the specialty of neurointervention has continuously evolved, especially through the efforts and passion of Professor Pierre Lasjaunias. Articles in INR are submitted by authors in many countries worldwide and are peer reviewed by international referees. Considering that interventional neuroradiology is the highly specialized field that INR pursues, the impact factor or the Eigenfactor score of INR is still very low partly because the LinkOut services, including PubMed, are not yet provided in a sufficiently open way. Ethical research standards should also be emphasized in INR.

The most important issue when dealing with a patient with a brain AVM is the decision whether to treat or not. Only after this decision has been made, taking into consideration a number of factors depending on both the patient and the specific type of AVM, can the best option for treatment be chosen.

An operative classification of brain AVMs, previously adopted in the Department of Neuroradiology and Neurosurgery of Verona (Italy) and published in this journal, was subjected to validation in a consecutive group of 104 patients clinically followed for at least three years after completion of treatment.

This classification, slightly modified from the original version concerning the importance of some specific items, allowed us to assess the indication to treat in each case, whatever type of treatment was offered to the patient.

Onyx is increasingly used in endovascular therapy of intracranial arteriovenous malformations (AVMs). However, the embolic effect and post-embolization management are still under discussion. We report our experience in the treatment of supratentorial brain arteriovenous malformations (SBAVMs) with Onyx and discuss post-embolic management.

From June 2006 to July 2008, 20 patients with SBAVM were embolized with Onyx. There were 14 men and six women ranging from 14 to 64 years of age (mean 38.3 years). Initial symptoms included spontaneous hemorrhage (n=12), headaches (n=4), seizure (n=3) and incidentally disclosed after head trauma (n=1). After the endovascular procedure, all had subsequent treatment (follow-up angiogram, stereotactic radiosurgery or microsurgery) according to the obliteration degree.

At angiography, seven patients (35%, 7/20) were completely obliterated (over 95% closure) after embolization while one suffered a small subarachnoid hemorrhage without permanent clinical sequelae. Four patients (20%, 4/20) were subtotally obliterated (over 80% closure), one patient who suffered severe cerebral edema after embolization underwent decompressive craniectomy, two patients had additional radiosurgery and one patient had follow-up angiogram. Nine patients (45%, 9/20) were partially obliterated (20–80% closure), five patients had additional surgery, two patients had additional radiosurgery and two patients had follow-up angiogram (one patient had intraventricular hemorrhage three months after embolization). Of all 20 AVMs, an average of 2.2 ml Onyx was used per patient and average volume reduction was 80% (range, 30%–99%).

Onyx is suitable for embolization of SBAVMs because of its diffuse controllable properties. We suggest clinical follow-up after complete obliteration, additional radiosurgery or angiographic follow-up after subtotal obliteration and additional surgery after partially obliteration. More cases with long-term follow-up are needed to evaluate the long-term prognosis of our post-embolization management.

3D road-mapping with syngo iPilot was used as an additional tool for assessing cerebral aneurysms and arteriovenous malformations (AVMs) for endovascular therapy. This method provides accurate superimposition of a live fluoroscopic image (native or vascular road-map) and its matching 2D projection of the 3D data set, delivering more anatomic information on one additional display. In the endovascular management of cases with complex anatomy, 3D road-mapping provides excellent image quality at the intervention site. This method can potentially reduce intervention time, the number of DSA runs, fluoroscopy time and the amount of contrast media used in a procedure, with reservation for these factors being mainly operator-dependent. 3D road-mapping probably does not provide any advantage in the treatment of cerebral aneurysms or AVMs with very simple configuration, and it should not be used when acquisition of an optimum 3D data set is not feasible.

Transverse/sigmoid sinus (TS) is the most common location for cerebral dural arteriovenous fistulas (DAVFs). Most of them are cured by venous embolization or a combination of arterial embolization and surgery/radiosurgery. Our goal was to reconsider the endovascular treatment strategy of TSDAVFs according to the new possibilities of arterial embolization using Onyx-18.

Nineteen patients with TSDAVFs were included in a prospective study between 2004 and 2007. Three of them had type I, four had type IIa, six had type IIa+b, three had type III, and three had type IV fistulas. Three presented with subarachnoid hemorrhage. The approach routes, angiographic results, complications, and clinical outcome were assessed. The mean clinical follow-up period was 32.5 months.

In one patient, the DAVF had been obliterated spontaneously at ten month follow-up. Complete angiographic cure was obtained in nine cases with one case of progressive thrombosis. Of these ten cures were achieved after a single procedure in seven out of ten patients who had not been embolized previously. Three patients were cured with sinus packing with prior arterial embolization. Among these 19 patients, 15 underwent follow-up angiography which confirmed the complete cure. Partial occlusion was obtained in nine patients, one was cured after additional surgery, and one underwent radiosurgery. Hallucination occurred in one completely cured patient on day one.

Based on this experience, we believe that intraarterial Onyx may be the primary treatment of choice for patients with TSDAVFs. The applicability of this new embolic agent indicates the need for reconsideration of the treatment strategy for such fistulas.

Onyx migration in the endovascular treatment of dural arteriovenous fistulas (dural AVFs) is uncommon. We describe five cases of Onyx migration to the heart and draining vein and its avoidance.

Between February 2007 and August 2008, Onyx migration was encountered in five patients with dural AVFs treated endovascularly at our institute. Procedures performed under general anesthesia consisted of two arterial approaches and three venous approaches.

Two patients with dural AVFs involving the transverse-sigmoid sinus were treated by transarterial embolization using Onyx-18 via the occipital artery and the posterior branch of the middle meningeal artery, respectively. A piece of Onyx was found in the right ventricle on post-embolization chest X-ray film in both patients, one developed tricuspid valve dysfunction requiring thoracic surgery and one was asymptomatic. The other three patients were treated with a combination of Onyx (34 or 18) and coils transvenously with venous Onyx migration leading to draining vein occlusion, one with dural AVF involving the tentorium died from venous rupture, two patients with bilateral dural AVFs of the cavernous sinus (one with deterioration of ocular symptoms and one without symptoms). Postoperative digital subtraction angiography confirmed the elimination of dural AVF in one patient, and residual fistulae in three patients. The follow-up study ranging from two to nine months (average, 4.5 months). Three patients recovered to their full activities, while one had visual disturbance.

Although Onyx has been considered a controllable embolic agent, its migration to other locations causing clinical deterioration can occur. This problem should be noted and prevented.

Peripheral cerebral aneurysms are difficult to treat with preservation of the parent arteries. We report the clinical and angiographic outcome of 12 patients with cerebral aneurysms located peripherally.

In the past five years, 12 patients, six females and six males, presented at our institution with intracranial aneurysms distal to the circle of Willis and were treated endovascularly. The age of our patients ranged from four to 58 years with a mean age of 37 years. Seven of the 12 patients had subarachnoid and/or intracerebral hemorrhage upon presentation. Two patients with P2 dissecting aneurysms presented with mild hemiparesis and hypoesthesia, one patient with a large dissecting aneurysm complained of headaches and two patients with M3 dissecting aneurysms had mild hemiparesis and hypoesthesia of the right arm. Locations of the aneurysms were as follows: posterior cerebral artery in seven patients, anterior inferior cerebellar artery in two, posterior inferior cerebellar artery in one, middle cerebral artery in two.

Twelve patients with peripheral cerebral aneurysms underwent parent artery occlusion (PAO). PAO was performed with detachable coils. No patient developed neurologic deficits.

Distally located cerebral aneurysms can be treated with parent artery occlusion when selective embolization of the aneurysmal sac with detachable platinum coils or surgical clipping cannot be achieved.

Intracranial hemorrhage following carotid artery stenting (CAS) is a rare but potentially devastating complication. The present study reviewed intracranial hemorrhage cases from patients undergoing CAS in ten years to find the methods to rescue patients from this fatal complication.

Patients with postoperative intracranial hemorrhage following CAS were retrospectively selected, and clinical features, treatments and outcomes were studied.

Ten patients with intracranial hemorrhage were identified. The mean onset time of hemorrhage was 6.1 ± 7.1 h. Intracerebral hemorrhage occurred in eight patients and SAH in two patients. The patients were treated by stopping anti-platelet and anticoagulant for at least three days, and surgical drainage of the hematoma/ventricle drainage or conservative treatment. Six patients survived, two had left moderate paralysis, four had a good recovery at four week follow-up, and four patients died. No patients underwent thrombosis in stent after withdrawing of antiplatelet and anticoagulant.

Intracranial hemorrhage after CAS occurs usually in a few hours and leads to catastrophic results. Once patients have intracranial hemorrhage, good neurocritical care may help to save them. Stopping antiplatelet and anticoagulant for at least three days may avoid thrombosis in the stenting site.

Steroids are empirically used to medicate patients with myelopathy of unknown etiology. We report the reversible aggravation of neurological status after steroid administration in a patient with venous congestive myelopathy (VCM). We retrospectively evaluated 36 patients with angio-graphically confirmed spinal arteriovenous malformation (SAVM) from a prospectively collected neurointerventional database. We evaluated steroid medication and neurological aggravation using Aminoff grading and analyzed using Fisher's exact test whether steroid medication is related to neurological aggravation and spinal cord edema as demonstrated on MR T2-WI. Among 26 patients who had been treated with steroids, ten had aggravated neurological deficits. The aggravation in these ten patients was related to the steroid medication (P = 0.039 in all patients) and only marginally to VCM with spinal cord edema as seen on T2-WI (P = 0.074). Aggravation caused by using a high intravenous dose (250–1000 mg) of methylprednisolone or dexamethasone at 8–20 mg/day slowly decreased after stopping the steroid medication. Steroids were reversibly detrimental in patients with VCM caused by SAVM. A history of neurological aggravation after the use of steroids may suggest the diagnosis of SAVM associated with VCM.

The prevalence rate of low back pain in a number of studies ranged from 22% to 65% in one year, and lifetime prevalence ranged from 11% to 84%. Over the years many percutaneous minimally invasive therapeutic modalities have evolved. Intradiscal oxygen-ozone therapy has also showed promising results. We undertook a prospective cohort study to evaluate the therapeutic outcome of oxygen-ozone therapy on patients with lumber disc herniation in the Indian population.

After obtaining ethical committee and investigational review board permission, 53 consecutive patients complying with selection criteria were treated with a single session of oxygen-ozone therapy. All presented with clinical signs of lumber nerve root compression supported by CT and MRI findings. All patients received 3–7 ml of ozone-oxygen mixture at an ozone concentration of 29–32 mc/ml of oxygen. Therapeutic outcome was assessed after three weeks, three months, six months, one year and two years on a visual analog scale and Oswestry low back pain disability questionnaire.

Pain intensity was significantly reduced following treatment (VAS baseline 7.58 ± 0.86, after three weeks 2.75 ± 1.42 and after two years 2.64 ± 2.14). Similarly the Oswestry disability index showed a remarkable improvement in the functional status of the patients (p<0.05). No major complication was observed in this case series. Oxygen-ozone treatment is highly effective in relieving low back pain due to lumber disc herniation.

Polymethylmethacrylate, as a widely used material for vertebroplasty, has several drawbacks such as heat development and high allergenic potential. In order to avoid these drawbacks ceramic cement materials have been developed.

The purpose of this study was to evaluate a new biointegrative material for vertebroplasty in osteoporotic vertebral fractures regarding pain relief, safety aspects and technical feasibility.

The injectable bone substitute Cerament™ SpineSupport has been developed for vertebroplasty of osteoporotic vertebral fractures. The aim of the product is to provide mechanical stability by cured calcium sulfate dehydrate during a period of several weeks and to act as an osteo-conductive support by hydroxyl apatite particles.

Inclusion criteria were a stable single vertebral fracture at levels Th5 to L5, verified by CT and MRI, and not older than four weeks, in osteoporotic patients aged 60 years or older. Bipedicular vertebroplasty technique was used. Follow up included CT directly after treatment and after two month and pain assessment (VAS) pre and post procedure after two weeks and one month.

Seven patients (age range 62 – 96 years, mean 73.9, five women, two men) were treated at levels T 8 (n=1), T 12 (n=4) and L1 (n=2). The average injected volume was 1.9 ml (range 0.2 – 4 ml). No material or procedure-related complications were observed. An average height loss of the treated vertebral bodies of 3.6 mm (range 1.5 – 5.4) was seen two months after treatment as compared to pre-treatment CT. Pain assessment by VAS resulted in an improvement from mean 69 prior treatment to 37 the day post treatment, 42 after two weeks and 30 after one month.

Initial results indicate that Cerament™ SpineSupport is safe and effective in the treatment of acute osteoporotic vertebral body fractures. Further studies with long-term follow-up are needed to confirm these results and to prove the concept of osteoconduction with hydroxyl apatite particles.

This study evaluated the outcomes of endovascular management for P2-segment aneurysms. From 2003 to 2008, 14 consecutive patients with P2 aneurysms were treated endovascularly by proximal P2 segment occlusion at our institution. The aneurysms included 12 P2a and two P2p aneurysms. Presenting symptoms were caused by subarachnoid hemorrhage (SAH) in six patients, stroke in five, and isolated headaches in three. Mean follow-up was 14 months. Twelve aneurysms were treated with proximal P2 segment occlusion without parent artery revascularization. Twelve aneurysms were at the P2a and two aneurysms at the P2p. Two patients developed hemianopsia after the procedure and one recovered completely within six months follow-up with one still persistent at 22-month follow-up. Proximal parent vessel occlusion was a relatively safe, effective treatment for P2 aneurysms that posed low risk for early or delayed ischemia or infarction.

A fusiform aneurysm in the terminal M1 middle cerebral artery (MCA) segment was treated by a construction of a high-flow arterial extracranial-intracranial (EC-IC) bypass. Due to severe bypass vasospasms, local vasodilating agents together with percutaneous angioplasty and stent implantation were applied, but failed due to subsequent bypass occlusion. To remedy this complication a new bypass was created from a segment of the saphenous vein, followed by MCA aneurysm embolization and parent artery occlusion. One year after the surgery, the venous bypass remains patent and the aneurysm occluded, with the patient fully active, without any neurological sequelae.

We describe the case of a patient with an aneurysm of the P2 segment of the PCA with a persistent anastomosis between the posteromedial choroidal artery and the P3 segment of the posterior cerebral artery.

We describe two rare cases of spontaneous closure of cerebral dural arteriovenous fistulas (DAVFs) with a small nidus and draining directly in a single cortical vein with several ectasias.

Eighteen previously published cases of spontaneous closure of cerebral DAVF comprised more benign fistula types. In literature, several explanations for DAVF occlusion have been proposed. We hypothesize that, in addition to the known causes, the specific contrast medium used during the diagnostic selective angiography might have played a role in the thrombosis and subsequent fistula closure.