Abstract
Oral Abstract 1st Place
Comparative Analysis Of Predictive Criteria For Unassisted Maturation Of Avf Using Post-Operative Ultrasound Measurement: Uab Vs Nkf-Kdoqi
1Seoul St. Mary’s Hospital, Division of Nephrology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
2Incheon St. Mary`s Hospital, Division of Nephrology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
The study aimed to assess the predictive performance of the University of Alabama at Birmingham (UAB) criteria versus the NKF-KDOQI guidelines in determining the likelihood of unassisted arteriovenous fistula (AVF) maturation. Additionally, we aimed to investigate how the predictive performance of these criteria differs between upper arm AVFs and forearm AVFs.
We retrospectively analyzed the age, gender, BMI, and comorbidities of chronic kidney disease patients who underwent AVF creation and were followed up from January 2017 to March 2021 at a single medical center. Additionally, we examined the types of AVFs, the success of the first cannulation, and postoperative AVF ultrasound measurements.
Among a total of 560 patients, unassisted maturation of AVFs was confirmed in 68.6% of cases. Specifically, the unassisted maturation rate for upper arm AVFs was 70.2%, which was higher than the rate of 66.8% observed for forearm AVFs. While the positive predictive value for the overall unassisted maturation of AVFs was higher for NKF-KDOQI at 0.85 compared to UAB's 0.77, UAB demonstrated superior negative predictive value at 0.57. Evaluating the predictive abilities of both criteria through Receiver Operating Characteristic Curve analysis, UAB (AUC = 0.643 (95% CI 0.602 – 0.684)) outperformed NKF-KDOQI (AUC = 0.56 (95% CI 0.532 – 0.589)) in predicting unassisted maturation of overall AVFs. Notably, when predicting unassisted maturation for forearm AVFs, UAB (AUC = 0.654 (95% CI 0.593 – 0.715)) demonstrated superiority over NKF-KDOQI, whose predictive ability (AUC = 0.517 (95% CI 0.494 – 0.540)) approached random chance.
In conclusion, the UAB criteria demonstrated superiority in predicting the overall unassisted maturation of AVFs compared to the NKF-KDOQI guideline. This trend was particularly pronounced in the case of forearm AVFs, where the predictive ability of NKF-KDOQI criteria for unassisted maturation was found to be close to random chance.
Oral Abstract 2nd Place
Inpatient Versus Ambulatory Percutaneous Thrombectomies For Dialysis Access: An Assessment Of Outcomes Using A Large Multicenter Database
Truong, H1, Corbett, B E2, Kubomoto, S1,2, Dawoud, D Z3
1HCA Riverside in Riverside, CA
2University of California Riverside, School of Medicine in Riverside, CA
3Nephrology Medical Associates in Riverside, CA
End-stage renal disease (ESRD) patients require frequent vascular access maintenance for effective hemodialysis. Arteriovenous (AV) fistula or graft thrombectomies can be performed in inpatient or outpatient settings, with inpatient percutaneous thrombectomy (IPT) costing up to four times more than ambulatory percutaneous thrombectomy (APT). Researches from Spain and the U.S. show that APT reduces hospital stays, missed dialysis, and costs; one study also found fewer infections and lower mortality with APT compared to hospital outpatient settings. Clinical outcomes in non-emergent IPT remain uncertain. Additionally, we suspected that many IPT patients might not have had clinical characteristics requiring emergent thrombectomy. This study compares APT and non-emergent IPT regarding outcomes such as hyperkalemia, bacteremia, pneumonia, sepsis, and re-thrombosis within 30 days to inform interventionalists about optimal care settings for ESRD patients.
The TriNetX research network, with data from 68 U.S. healthcare institutions, was queried for patients with ESRD or receiving dialysis who underwent AV fistula or graft percutaneous thrombectomy (PT) between 2007 and 2023. Patients were grouped into inpatient and outpatient cohorts, excluding those with acute conditions indicating urgent dialysis needs. Propensity score matching controlled for confounders, aligning cohorts by demographics and comorbidities. Clinical outcomes within 30 days post-PT, including hyperkalemia, bacteremia, pneumonia, sepsis, graft complications, and re-thrombosis, were evaluated using TriNetX’s data tools.
Of 11,094 IPT cases, 4,492 without acute clinical conditions were deemed non-emergent, and included in the analysis. IPT patients had higher risks than APT patients for all outcomes: 3.6 times for hyperkalemia (95% CI: 1.8–7.0), 2.4 for bacteremia (95% CI: 1.2–4.9), 5.8 for pneumonia (95% CI: 2.9–11.2), 4.5 for sepsis (95% CI: 2.2–8.8), 3.2 for graft complications (95% CI: 1.5–6.4), and 1.5 for re-thrombosis (95% CI: 1.2–1.8) within 30 days.
Our findings align with previous studies indicating that APT results in fewer graft complications, re-thrombosis, and infections within 30 days compared to IPT. Even after excluding acutely ill patients requiring urgent dialysis (e.g., hypoxia, metabolic acidosis, or severe hyperkalemia) to reduce confounding factors, IPT remained associated with a higher risk of adverse outcomes. Notably, over 40% of IPT cases lacked clear indications for emergent dialysis or hospitalization, suggesting a significant opportunity to transition these thrombectomies from inpatient to outpatient settings. In urgent scenarios such as hyperkalemia or volume overload, the 2019 KDOQI guidelines recommend using a temporary central venous catheter instead of immediate IPT, further reinforcing the potential for deferring IPT to APT. Our study highlights the advantages of APT in both cost and clinical outcomes, supporting a shift toward outpatient management where appropriate. The lack of clear APT selection criteria in KDOQI guidelines highlights the need for more specific recommendations to improve outcomes and reduce costs. Further research comparing thrombectomy techniques, such as rheolytic versus mechanical approaches, may enhance vascular access strategies and optimize care for ESRD patients.
Oral Abstract
Comparison Of 6-Month Reintervention Rates Following Treatment With The Wrapsody Cell-Impermeable Endoprosthesis Versus Percutaneous Transluminal Angioplasty
1St. Joseph Heart and Vascular Center, Orange, California, USA
2Tarrant Nephrology, PPG Health, Fort Worth, Texas, USA
3Chicago Access Care, Westmont, Illinois, USA
4North Carolina Nephrology, Raleigh, North Carolina, USA
5Liv Care Centro Clínico, Niterói, Rio de Janeiro, Brazil
6University of North Carolina Kidney Center, Chapel Hill, North Carolina, USA
7W.G. (Bill) Hefner Salisbury Department of Veterans Affairs Medical Center, Salisbury, North Carolina, USA
8Department of Interventional Radiology, Queen Elizabeth Hospital Birmingham, University Hospital Birmingham, United Kingdom
Percutaneous transluminal angioplasty (PTA) is the standard intervention used for stenosis in the venous outflow circuit of hemodialysis patients with arteriovenous fistulae/grafts (AVF/AVG); however, its effectiveness is often transient at best. As a result, repeated interventions are commonplace for this patient population. The Wrapsody Cell-Impermeable Endoprosthesis was recently developed to prolong vascular access in hemodialysis patients. Results from the randomized arm of the pivotal WRAPSODY AV Access Efficacy (WAVE) study have demonstrated there are significant clinical benefits of WRAPSODY vs. PTA; however, a comparative analysis of differences in reintervention has yet to be conducted. This post-hoc analysis addresses this knowledge gap.
The WAVE study is a prospective, multicenter, international trial (NCT04540302) conducted across 43 centers in the United States, South America, and the United Kingdom. The randomized arm of the study included patients with venous outflow stenosis or occlusion in their AVF who were randomized 1:1 to treatment with WRAPSODY or PTA. Treatment efficacy was based on the proportion of patients with a target lesion primary patency (TLPP), defined as freedom from clinically driven target lesion revascularization or target lesion thrombosis. The safety profile of WRAPSODY was determined based on the proportion of patients without any localized or systemic safety events. Kaplan-Meier analyses were conducted to determine time to event; log-rank tests were used to determine statistical significance (threshold 0.05).
A total of 122 patients were randomized to treatment with WRAPSODY and 123 to PTA. At 6 months, TLPP was significantly higher for patients treated with WRAPSODY vs. PTA (89.8% vs. 62.3%; p<0.0001). Access circuit primary patency was also significantly higher for patients treated with WRAPSODY vs. PTA (72.6% vs. 57.9%; p=0.015). A similar proportion of patients were free from safety events 30 days post procedure (WRAPSODY: 96.6%; PTA: 95.0%; p=0.53). The mean number of interventions to maintain target lesion patency was significantly lower in the WRAPSODY vs. PTA cohort (0.18 vs. 0.47, p<0.0001). The mean number of interventions to maintain access circuit patency was significantly lower for the WRAPSODY vs. PTA cohort (0.48 vs. 0.78, p=0.018). At 6 months, significantly more patients treated with PTA vs. WRAPSODY required target lesion reintervention (38.9% vs. 13.7%, p<0.0001) as well as any reintervention in the access circuit (42.1% vs. 28.3%, p=0.021). Among patients who required reinterventions, the mean time ±SD to the first intervention of the target lesion was longer for the WRAPSODY cohort as compared to the PTA cohort (103.5 ±43.3 vs. 88.2 ±55.2 days). For any reintervention within the access circuit, the mean time to reintervention was 89.3 ±51.9 and 79.9 ±50.2 days for patients in the WRAPSODY and PTA cohort, respectively.
WRAPSODY has demonstrated significant clinical benefits relative to PTA through 6 months, including longer time to reintervention, for hemodialysis patients who experience stenosis in their venous outflow circuit. The ability to prolong vascular access without the need for repeated interventions can help improve patients’ quality of life. As the WAVE study will collect data through 24 months, confirmation of these findings over the longer term will be forthcoming.
RapidFire Abstract 1st Place
Real-time angio zonal diversion via acoustic navigation (razdan) ligation; a multicentric, multispeciality, retrospective evaluation of 154 patients using an ultrasound guided, minimally invasive technique to divert flow and maximize cannulation probability in percutaneous arteriovenous fistulae
1Azura Vascular Care of Jacksonville, Jacksonville, FL
2Star Vascular Care, San Antonio, TX
3Fresenius Medical Care, Waltham, MA
4Spartanburg Medical Center, Spartanburg, SC
5HealthQare Services, Arlington, VA
Successful cannulation of an arteriovenous fistulae (AVF) is arguably the most important indicator of a successful access creation. Percutaneous Arteriovenous fistula (pAVF) can present challenges in achieving successful cannulation due to insufficient maturation and/or compromised flow dynamics. Developing algorithms that promote successful maturation and achieving appropriate flow within the target cannulation vein are necessary for developing a cannulatable pAVF and therefore a successful access. The Real-time Angio Zonal Diversion via Acoustic Navigation (RAZDAN) technique is an innovative, ultrasound-guided, minimally invasive procedure designed to divert blood flow and improve cannulation rates, ideal for non-surgical practitioners. This multicentric, multispecialty retrospective study evaluates clinical outcomes of this innovative approach across varying geographical locations.
A retrospective analysis was conducted of 154 End Stage Renal Disease (ESRD) patients on hemodialysis who underwent the RAZDAN ligation for immature Ellipsys pAVF between 2019 and 2024. Ultrasound guidance was used to recognize optimal zones for ligation, with real-time ultrasound imaging to ensure precise identification of the target vein. The primary outcomes measured were technical success rates, infection rates, and persistence of occlusion to at least 6 months. Additional pertinent outcomes evaluated were time between access creation, maturation, ligation, and catheter removal. Significant Adverse Events (AE) related to the procedure and patient demographic information were also recorded.
The RAZDAN ligation technique represents a promising minimally invasive approach to enhancing cannulation probability in immature pAVF. By using real-time ultrasound guidance (acoustic navigation), this method optimizes flow diversion with minimal complications. Further prospective studies are warranted to validate these findings and assess long-term outcomes, especially given the potential for wider applications of the technique.
RapidFire Abstract 2nd Place
Determinants Of Arteriovenous Fistula Maturation In Hemodialysis Patients: Impact Of Demographic And Vascular Factors
1University of Kerbala College of Medicine, Department of Medicine and Nephrology, Karbala, Iraq
2Al-Saegh Center for Nephrology and Kidney Transplantation, Department of Radiology, Karbala, Iraq
3Al-Saegh Center for Nephrology and Kidney Transplantation, Dialysis Unit, Karbala, Iraq
Arteriovenous fistulas (AVFs) are the preferred choice for hemodialysis access due to their superior long-term patency and lower complication rates. However, AVF maturation remains a challenge, influenced by a variety of patient-specific and clinical factors. This study aimed to assess the prevalence of mature AVFs and identify the impact of demographic and medical factors on their maturation.
A prospective cohort study was conducted on 650 patients with newly created brachiocephalic AVFs for hemodialysis in two medical centers. Patients were evaluated using color Doppler ultrasonography on postoperative days 7 and 42. AVF maturation was defined using criteria from the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) with a cut-off of 600 mL/min, and the University of Alabama at Birmingham (UAB) criteria with a cut-off of 500 mL/min. Demographic information and clinical characteristics, including age, gender, body mass index (BMI), diabetes mellitus, hypertension, heart failure, peripheral vascular disease, ischemic heart disease, and smoking status, were recorded. Statistical analysis was conducted using chi-square and ANOVA tests with a significance level of p ⩽ 0.05.
Out of 650 patients, 71% achieved AVF maturation, while 29% experienced maturation failure. The study revealed a significant association between peripheral vascular disease (PVD) and AVF maturation failure (p < 0.05), indicating that PVD plays a crucial role in impairing AVF outcomes. However, other demographic and clinical factors, including age, gender, BMI, diabetes mellitus, hypertension, heart failure, ischemic heart disease, and smoking status, did not show statistically significant associations with AVF maturation (p > 0.05). The average flow velocity of mature AVFs increased significantly from 82.15 ± 4.79 mL/min on day 7 to 608.73 ± 97.07 mL/min on day 42 (p < 0.001), highlighting the importance of regular Doppler monitoring. The findings underscore the multifactorial nature of AVF maturation, where the presence of PVD emerged as a critical determinant, while other common comorbidities had limited or no measurable impact. These results align with previous research emphasizing the need for vigilant vascular management in patients with PVD to improve AVF outcomes.
Identifying and managing vascular risk factors, particularly peripheral vascular disease (PVD), is crucial for enhancing AVF maturation in hemodialysis patients. Doppler ultrasonography is recommended for early detection of complications to ensure timely interventions. Further large-scale studies are necessary to explore the impact of comorbid conditions and demographic factors on AVF outcomes.
RapidFire Abstract 3rd Place
Untangling Thrombectomy Failures: How Complex Stenosis And Treatment Choices Influence Recurrence And Access Loss Risk
1Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI
Arteriovenous accesses (AV) are the preferred standard of care for ESRD patients requiring hemodialysis. Often, these AV accesses whether native or graft fail due to thrombosis. This can lead to dependence on catheters. Therefore, swift endovascular interventions remain the best approach to remove thrombus and restore flow in the circuit. Despite the widespread use of chemical thrombectomy agents like Alteplase and Heparin, and introduction of mechanical thrombectomy devices like Cleaner, Penumbra and Angiojet, there is risk of thrombectomy failure and recurrent thrombosis. This study looks at the risk factors associated with thrombectomy failure or instant recurrence.
This is a retrospective chart review of patients presenting to the interventional nephrology suite for thrombectomy of their thrombosed dialysis access from June 1st, 2021, and May 30th, 2024. Unsuccessful thrombectomy was defined as the failure to restore the blood flow at the end of the procedure, need to place a dialysis catheter during the procedure, or return of the patient for repeat thrombectomy or dialysis catheter placement before getting any outpatient dialysis session after the reviewed procedure. Access loss in 90 days was defined as abandonment of the access due to inability to use the access for any further dialysis, resulting in placement of a catheter or a new access placement. Demographics, underlying co-morbidities, access type, anatomy and history, and thrombectomy procedure related factors were compared between the two groups.
A total of 98 patients underwent thrombectomy. 47% met the definition of unsuccessful thrombectomy. There was no difference between successful and unsuccessful thrombectomies in terms of the type of access, vintage, use of anticoagulation, or previous interventions on the accesses. However, unsuccessful thrombectomy cases presented with greater initial stenosis severity (mean 90% vs. 80% in successful cases, p=0.03), higher residual stenosis post-procedure (mean 46% vs. 10%, p<0.001), and received smaller balloon sizes (mean size 6.0 mm vs. 8.0 mm, p=0.002). Additionally, the use of adjunctive agents, such as TPA (Alteplase) and Heparin, was significantly lower in unsuccessful cases (Alteplase usage: 63.0% vs. 86.5%, p=0.007; Heparin usage: 67.4% vs. 90.4%, p=0.005), highlighting procedural variations between the groups. Outcome analysis indicated a substantial disparity in recurrence risk within 30 days, with unsuccessful thrombectomy cases showing a 54.3% recurrence rate compared to 25.0% in successful cases (p=0.003). Similarly, the likelihood of access loss within 90 days was significantly higher in the unsuccessful group, with a rate of 71.7% compared to 19.2% (p<0.001).
The study demonstrates that unsuccessful thrombectomy is closely associated with severe lesions difficult to address with standard angioplasty, particularly when larger balloons or thrombolytic agents are not employed. These findings underscore the challenge posed by more complex, treatment-resistant lesions. It emphasizes the utility of thrombolytic agents. These cases are linked to an increased risk of both short-term recurrence and long-term access loss, emphasizing the need for tailored intervention strategies in managing severe stenosis cases.
RapidFire Abstract 1
Real world comparison of the outcomes after angioplasty with standard non drug coated, lutonixtm and in.pacttm drug coated balloons (dcb) in dialysis access
1University Of Wisconsin School of Medicine and Public Health, Department of Nephrology (Interventional), Madison, WI
AVFs are the preferred choice for hemodialysis access due to superior patency, longer survival and lower complication rates compared to grafts or catheters. However, AVFs are still associated with high primary failure rates and recurrent stenosis from neointimal hyperplasia and subsequent thrombosis. Traditional percutaneous transluminal angioplasty using uncoated balloons, often lead to higher rates of restenosis and repeated interventions, affecting up to 60% to 70% of patients within a year. LutonixTM and IN.PACTTM peripheral drug coated balloons (DCBs) have shown superior primary patency, longer time to recurrence and non-inferior safety profile compared to standard non coated angioplasty balloons. There are inherent differences between these two DCBs in terms of the dose of Paclitaxel, balloon design, and the type of paclitaxel carrier. We previously reported the real word comparison of the outcomes after angioplasty with LutonixTM DCB and standard balloon which showed that there was no difference. In this study, we aim to compare standard, LutonixTM and IN.PACTTM balloons which each other.
A retrospective chart review analyzed ESRD patients with arteriovenous fistula (AVF) at our center who underwent angioplasty for various reasons related to dysfunctional access from January 1, 2018, to September 30th, 2023. We compared three types of balloons used for angioplasty: standard non-drug-coated balloons, the LutonixTM DCB, and the IN.PACTTM DCB. Outcomes were evaluated based on the need for re-intervention at 3, 6, and 12 months, and average number of re-interventions and access loss in the 12 months follow up period.
During the study period, 143 angioplasties were done using the regular non-DCBs, 59 were done using LutonixTM and 43 were done using IN.PACTTM. There was no statistically significant difference in baseline demographics and clinical co-morbidities of the patients among the three groups. In terms of the index procedure related findings, IN.PACTTM balloon was used more often for outflow and cephalic arch stenosis, and less often for inflow, instent and central stenosis compared to standard and LutonixTM balloon. Initial lesions were more severe in the LutonixTM and IN.PACTTM balloon groups. There was no significant difference in the incidence of recurrence at 3, 6 and 12 months between the groups. There was no difference in the average number of recurrences during the 12 month follow up, except IN.PACTTM balloon had slightly lower number of recurrences when compared to standard balloon (1.64 vs 1.23 p-value 0.04). Similarly, there was no difference in the incidence of access loss in each group during the 12 months follow up. When adjusted for initial severity, site of the lesion and recurrent or de novo lesion, IN.PACTTM had slightly lower risk of recurrence at 6 months compared to LutonixTM (0.44 vs 0.61, p-value 0.04).
To our knowledge, this is the first study comparing the outcomes of angioplasty of the AVF with LutonixTM and IN.PACTTM drug coated balloons with each other, as well as with standard non-DCB. We did not find any major advantage in using a DCB to reduce the risk of recurrence after AVF angioplasty, except a slight with IN.PACTTM. This is contrary to the results of the clinical trials on these balloons. The lower number of procedures with LutonixTM and IN.PACTTM balloons may have impacted our results. Larger studies should be done to confirm our findings.
RapidFire Abstract 2
Redefining Urgent-Start Peritoneal Dialysis: Enhancing Safety And Technique In Tenckhoff Catheter Placement
Cortez Flores, B1, Garrido Roldán, R1, Barrientos Maldonado, C2, Moreno Novales, R3, Balderas Juárez, J3, Hernández Ortega, R3, Galindo Vallejo, P E4, Reyna Blanco, J4, Moguel González, B1
1Interventional Nephrology Department, Instituto Nacional de Cardiología “Ignacio Chávez”, Mexico City, México
2Nephrology Department, Centro Médico ISSEMyM Ecatepec, Mexico State, México
3Nephrology Department, Hospital General de México “Dr. Eduardo Liceaga”, Mexico City, México
4Nephrology Department, Hospital General “Dr. Manuel Gea González”, Mexico City, México
Urgent-start peritoneal dialysis (USPD) is defined as peritoneal dialysis initiated within 14 days of catheter insertion and has traditionally been avoided for many reasons. International guidelines recommend delaying dialysis for 2 weeks after PD catheter insertion where practicable because of increased risk of mechanical complications. There is only a randomized comparative study that evaluates the USPD outcome between low-volume (500mL) and full-volume initiation (2000mL), with no significance differences.
To determine the complications of three catheter placement techniques with immediate-start peritoneal dialysis (IPD), defined as initiation in the first 24 hours.
Prospective multicenter cohort study (4 centers) from April 2019 to April 2024. All peritoneal dialysis catheter placements were recorded regardless of the indication, including chronic patients with immediate-start criteria. Three placement techniques were evaluated by nephrologists and surgeons (stylet-guided, percutaneous non-ultrasound guided and percutaneous ultrasound-guided.
631 patients were analyzed, 60.1% were women, mean age 55 years and 67.8% had type 2 diabetes. The techniques used were: classical 206 (32.6%), Seldinger 243 (38.5%) and surgical 185 (29.3%). Forty-one percent had a history of surgery and this did not influence the complication rate in any of the techniques. 80.6% of patients started therapy in < 24 h (IPD) with full volume (2000mL), of which 52.1% did so in the first 6 h. Only 19.4% received UPD. The most frequent complications were mechanical (23.9%), there were no differences in the total complications between each of the techniques; however, exit site infection was more frequent with surgical placement (6% vs 0.9%, p<0.001). Percutaneous techniques required catheter repositioning more frequently (15.3% vs 7.14%, p<0.001), although only 8.7% required a change of modality.
Nephrologist-initiated peritoneal dialysis programs are associated with better success rate, superior catheter survival, shorter hospital stays and shorter catheter break-in time compared with surgical peritoneal dialysis catheter placement. The technique and the initiation with full volume in the first 24 hours did not alter the complications of IPD. This new modality has a low complication rate, comparable to elective placement, so it is safe to use and represents a less expensive and faster option. In our country, early initiation is routine thanks to percutaneous techniques that allow immediate initiation (< 24 h).
RapidFire Abstract 3
Vexus Protocol And Lung Ultrasound (Lus) In The Evaluation Of Immediate Post Transplant (Posktx) Volemia
Sosa Barrios, RH1-3, Mínguez Toral, I1, Burguera Vion VM1,2, Galeano Álvarez, C1,2, Elías Triviño, S1,2, Roncal Redín, M4, Sánchez Iglesias, JF1, Moreno García, R1, Fernández Lucas, M1-3, Rivera Gorrín, ME1-3
1Nefrología, Hospital Universitario Ramón y Cajal, IRyCIS, Madrid
2Grupo de Nefrología Diagnóstica e Intervencionista de la Sociedad Española de Nefrología (GNDI)
3Universidad de Alcalá de Henares, UAH, Madrid
4Servicio de Medicina Preventiva, Hospital Universitario Ramón y Cajal, IRyCIS, Madrid
Accurate volume assessment in the immediate posKTx period reduces morbidity and mortality, saving resources. LUS, VExUS score and bioimpedance (BIA) are volume evaluation methods on the rise.
Prospective single-center study (April-December 2023) of 31 patients (Group1): volume assessed with ultrasound (US) versus 40 previous KTx (Group 2) assessed only clinically. Volume assessed days+1 and +7 (LUS, VExUS, BIA and physical examination (PE)).
There were no significant differences at baseline or in posKTx evolution (% delayed function, RRT, duration of hospitalization or cardiovascular events (CVD), nor between weight gain at day+1, although there were 6 acute pulmonary edema in group 2 (post-KTx) and only 2 post-discharge in group 1. BIA was not correlated with PE (p 0.022). VExUS score and BIA did not correlate.
BNP and Ca125: 88% with CVD had elevated BNP and 22% with elevated Ca125. Of those requiring hemodialysis, 85.7% had elevated BNP and 14.2% elevated Ca125.
VExUS score:
Day+1 VExUS 1 (3): 50% have elevated BNP but all normal Ca125. VExUS 2 (1) elevated Ca125 and BNP. VExUS 3 none.
Day+7 VExUS 1 (4): 75% elevated BNP and 25% elevated Ca125.
VExUS and LUS: Day+1 and +7 detected hypervolemia in patients with normal PE (3 patients had mild edema and VExUS 1-2, 9 pathological LUS without clinical edema or only mild), although not significantly.
VExUS at day+1 modified treatment in 77.6% and day+7 in 30% as follows:
VExUS day 1
• No 7 (22.6)
• Reducing iv fluids 22 (71.0)
• Reducing iv fluids + Diuretics 1 (3.3)
• Lower limb edema due to lymphocele 1 (3.3)
VExUS day 7
• No 19 (70.1)
• Reducing iv fluids 2 (7.4)
• Stopping iv fluids 2 (7.4)
• Other findings 3 (11.1)
• Retroperitoneal bleeding 2
• Perirenal haematoma 1
• Haemodialysis 1 (3.7)
LUS and VExUS outperformed physical exam in the accurate management of immediate posKTx volume, detecting hypervolemia early and modifying the therapeutic attitude up to almost 78% of cases. In our experience, BIA correlated poorly with volume status in these patients.
RapidFire Abstract 4
Mechanical Thrombectomy Of Thrombosed Hemodialysis Access Using A Novel Percutaneous Device: A Single Center Experience
1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
2Brigham and Women's Hospital, Harvard Medical School, Boston, MA
To evaluate the effectiveness and safety of a novel device (InThrill Thrombectomy System, Inari Medical, Irvine, CA) and to describe an innovative use of this device in preventing central embolization of thrombus during percutaneous thrombectomy of hemodialysis accesses.
We retrospectively analyzed medical records to identify and collect data on patients over the age of 18, who underwent thrombectomy procedures using the study device between 7-1-2023 and 10-7-2024. Our standard technique consists of thrombus maceration and aspiration using a 7 Fr. aspiration catheter, 2mg tPA, and removal of the arterial plug using an over-the-wire Fogarty embolectomy catheter. Thrombectomy devices are added if clinically indicated. Large-volume thrombectomies are approached using the sheath hole thrombectomy technique. Data on patient demographics, access age, and type, thrombectomy devices used, procedure time, radiation dose, adverse events, and outcomes, were collected.
During the study period, the study device was employed in 43 thrombectomy procedures in 38 patients out of over 300 total thrombectomies. The decision to use the device was based on the presence of thrombus resistant to removal by our routine technique or to prevent central embolization of thrombus, especially in case of large volume of thrombus. The study population included 23 males and 15 females using 15 AVFs (39.4%) and 23 AVGs (60.6%), 13 biografts and 10 PTFE. The median access age was 552.5 days. In 11.6% of cases, the study device was used as a 2nd thrombectomy device. In 30.2% of cases the device was used to capture dislodged thrombus in the venous outflow and in 27.9%, it was placed in the venous outflow prior to Fogarty use to capture the arterial plug. The device was used during 7 sheath hole thrombectomies (16.2%) to capture residual thrombus after re-establishing flow. The technical success rate was 100% and the clinical success rate (successful completion of at least one full dialysis session after thrombectomy) was 90.6%. The primary patency (patency without adjunctive procedures or loss of patency events) at one month was 72%. The secondary patency (patency of access without abandonment, revision or surgical thrombectomy) at one month was 86.8%. There were no minor or major device-related complications in the follow-up period. Non-device-related complications included admissions to receive dialysis. Two patients who required prolonged (>48 hours) hospitalization (one death due to mesenteric ischemia) had onset of symptoms preceding the procedure.
The InThrill device is a safe and effective tool to achieve successful thrombectomies in accesses with difficult-to-remove as well as high volume thrombus. Its design facilitates position in the venous outflow to “capture” thrombus fragments during large access thrombectomies thereby preventing central venous embolization and possibly clinically relevant pulmonary embolization. The results are consistent with previously published data and expand the documented use of the device towards AVFs. The limitations of the study include its retrospective design and the fact that it is a single center with two providers.
RapidFire Abstract 5
Comparison Of Early Vs Late Experience With Percutaneous Arteriovenous Fistula Creation Using The Ellipsys Vascular Access System
Sharaf, R1, Reinhardt, J1, Cabrera, T1
1Azura Vascular Care, Star Vascular Access Center, San Antonio, TX
Percutaneous Arteriovenous Fistula (pAVF) offers a safe and reliable alternative to surgery for the creation of access in patients needing hemodialysis. The Ellipsys vascular access system is a minimally invasive option that allows for a pAVF to be created in the forearm between the proximal radial artery and the perforator vein.
The aim of this study is to report the learning curve for creating and maturing pAVFs using the Ellipsys vascular access system.
Retrospective chart review of patients referred for vein mapping between October 2018 to January 2024, comparing the first 50 procedures (early) to the last 50 procedures (late) performed in an outpatient center. Outcomes assessed included procedure time, time to maturation and number of secondary procedures required to mature the fistulas.
pAVFs were successfully created in 82% (41/50) of the patients in the early group versus 100% (50/50) of patients in the late group. The average procedure time was 41 minutes for the early group compared to 10.5 minutes for the late group. Average time to maturation and average number of secondary procedures required to mature the fistulas were 121 days, 3 procedures and 21 days, 1.16 procedures for early versus late groups, respectively.
The Ellipsys system allowed for successful creation of arteriovenous fistulas, however, there was a learning curve which improved outcomes over time.
Year (October 2018 – January 2024) Number of Procedures
2018 7
2019 126
2020 221
2021 226
2022 195
2023 141
2024 11
First 50 Procedures (Early) Last 50 Procedures (Late)
Procedure Time (Minutes) 41 10.5
Time to Maturation (Days) 121 21
Number of Secondary Procedures for Maturation 3 1.16
RapidFire Abstract 6
Measurement Of Cerebral Blood Flow Using Transcranial Doppler Ultrasound: Comparison Of Two Populations Of Patients In Chronic Hemodialysis
1Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubirán, Mexico City
2Médica Santa Carmen, Mexico City
3Department of Neurology and Psychiatry, Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubirán, Mexico City
Patients undergoing hemodialysis (HD) experience systemic and cerebral hemodynamic changes that are associated with cognitive impairment. However, the potential role of an arteriovenous fistula (AVF) in influencing cerebral blood flow during HD has not been thoroughly investigated. The objective of this study was to quantify and compare the hemodynamic changes at the cerebral level during an HD session in patients with an AVF versus those with a high-flow catheter (HFC).
This was a cross-sectional study in which controls were selected for AVF patients, matched for age, sex, and HD vintage. Three measurements of mean cerebral blood flow velocity (CBFV) were performed using transcranial Doppler ultrasound (during the first 15 minutes,120 minutes, and 240 minutes after HD). Other interventions were carried out before and after HD, including measurement of cardiac output (CO) and measurement of AVF flow velocity by Point-of-care ultrasound (POCUS).
A total of 50 patients were included in the study, 20 of whom were women, with a mean age of 56 years and a mean HD vintage of 3.2 years. Of the participants, 25 had an AVF (50%). There were no significant differences in baseline characteristics between the two groups. All patients experienced a decrease in CBFV, with an average reduction of 26.5%. This reduction was more pronounced in the AVF group compared to the HFC group (-30.6% vs. -22.4%, p = 0.178). The change in CO from pre- to post-HD was also more marked in the AVF group compared to the HFC group (-12.5% vs. -7.6%, p = 0.73). Similarly, the change in mean arterial pressure (MAP) was -11.3% in the AVF group and -9.4% in the HFC group (p = 0.90).
All patients in the study experienced a significant decrease in CBFV, CO, and MAP during the HD session. Notably, these changes were more pronounced in patients with an AVF, though no statistically significant difference was observed between the two study groups.
RapidFire Abstract 7
Endovascular Treatment Of Chronic Superficial Chronic Total Occlusion Lesions In The Cubital Fossa In Hemodialysis Patients With Radiocephalic Avf
1Department of Internal Medicine-Nephrology, Lifeline Vascular Clinic, Korea, Republic of Korea
2Department of Thoracic and Cardiovascular Surgery, Lifeline Vascular Clinic, Korea, Republic of Korea
The radiocephalic arteriovenous fistula is the first-choice vascular access for hemodialysis patients. However, when only the deep vein alone is drained through the perforator vein without the superficial vein in the cubital fossa area, the cannulation segment becomes pulsatile and abnormalities such as prolonged hemostasis and increased venous pressure during hemodialysis are common. Previously, interposition surgery using a prosthetic graft with an intact outflow vein was widely used. However, this method required the ligation of perforator veins to maintain blood flow through the graft. In the long term, stenosis often developed in the single outflow tract, compromising patency. We performed endovascular angioplasty of the superficial vein chronic total occlusion (CTO) lesion in the cubital fossa to restore the proper blood flow drainage system of the superficial vein while preserving the native vessels as much as possible.
A total of 121 CTO cases were seen at the Lifeline Clinic from February 2023 to November 2024. We conducted a retrospective study of 69 intervention cases in 64 patients with radiocephalic arteriovenous fistula and CTO of the cephalic vein or basilic vein (median antecubital vein) in the cubital fossa. Ultrasound surveillance was performed prior to recanalization procedures. A superficial vein was selected as the target if the length of the total occlusive lesion was not excessive, ultrasound tracing was feasible, and the condition of the outflow vein was intact. A guide wire was advanced through the CTO lesion using a catheter, followed by sequential balloon angioplasty. The treatment goal is the resolution of clinical indicators such as pulsatile patterns at the puncture site, increased venous pressure, and prolonged hemostasis. In terms of radiologic findings, it is to ensure that blood flow through the superficial vein precedes that through the deep vein upon completion of endovascular recanalization. If this could not be achieved with balloon angioplasty alone, stenting was considered to maintain patency.
Of the 67 cases, 48(71.6%) were left RC AVFs and 21(28.4%) were right RC AVFs. Recanalization of the occlusion was attempted from the basilic vein (median antecubital vein) in 34(50.7%) cases, from the cephalic vein in 32(47.8%) cases, and from both sides in 1(1.5%) case in a single procedure. Recanalization was successful in 58(86.6%) cases and unsuccessful in 9(13.4%) cases, of which 2 cases were recanalized in the next procedure. Of the 34 successful cases, post-procedural cumulative patency was maintained in 26(76.47%) cases and patency was not maintained in 4(11.76%) cases. There were 6(10.3%) cases where F/U was not achieved or the AV access had to be abandoned due to steal syndrome. The mean F/U duration was 214.5 days.
For RC AVF, endovascular restoration of the superficial vein CTO in the cubital fossa is a less invasive and sufficiently effect option for reliable cannulation and hemodialysis. Even if satisfactory patency cannot be achieved with the endovascular approach, it has the advantage that revision procedures such as straightening of the perforator vein or interposition surgery with a prosthetic graft can be performed using conventional methods. Although the median follow-up is relatively short, it is expected that further reports on long-term patency will be available as patients continue to be followed.
RapidFire Abstract 8
Expanding Access To Interventional Nephrology: Reduction Of Fistula Thrombosis Through An Ultrasound-Guided Angioplasty Program
1Nephrology Department, Associação Renal Vida, Blumenau, SC, Brazil
Arteriovenous fistula (AVF) dysfunction is a significant challenge in hemodialysis (HD) patients, especially in low-income settings where access to angioplasty is limited. In Brazil, the public health system does not support outpatient centers and patients experience long delays, with no access to endovascular procedures in some regions. To improve treatment accessibility, we started an ultrasound (US)-based angioplasty program, and here we present its results.
This retrospective study assessed the results of an outpatient, US-guided angioplasty program in a single HD facility in Brazil, including public health system patients. Patients with signs of AVF dysfunction were evaluated with Doppler US by an interventional nephrologist and symptomatic significant peripheral stenoses were treated with US-guided angioplasty. Procedures took place inside the HD facility, in an appropriate room. Cases with suspected central stenosis on US were referred to inpatient treatment and not included in this analysis. The primary outcome was the impact on thrombosis incidence. Secondary outcomes were success and complication rates of US-guided angioplasties and the effect on AVF prevalence.
A total of 73 interventions were performed exclusively under US guidance, on 46 accesses in 45 patients (50% males, mean age 56.29+-14.56 years). Hypertension was present in 86.7% and diabetes in 48.9%. AVF site distribution included 29 (63.0%) radiocephalic, 12 (26.1%) brachiocephalic, 3 (6.5%) brachiobasilic, and 2 (4.3%) forearm basilic. Of the interventions, 69 (94.5%) were angioplasties and 6 (8.2%) were total occlusion needle recanalizations, with 28 (38.4%) being reinterventions. The overall success rate was 95.89%, with three unsuccessful recanalization attempts. The incidence of thrombosis significantly decreased after program implementation, from 7.39% to 3.20% (Chi-square = 4.77, p = 0.028). In the 17 months before the first angioplasty, 18 thromboses occurred among 257 AVFs compared to 9 among 281 AVFs in the 17 months after. The prevalence of AVF has not significantly changed over the same period, starting at 67.45% and increasing to 76.10% (Chi-square = 2.11, p = 0.146). The complication rate was 4.1%, with two minor hematomas managed with balloon compression and one brachiocephalic AVF loss, which presented with low flow and imminent thrombosis due to a critical cephalic arch stenosis.
In Brazil and other low-income settings, limited access to surgical suites and fluoroscopy often impedes timely and effective management of AVF dysfunction, particularly in the public health system. Consequently, patients endure dysfunctional AVFs until thrombosis occurs, leading to access loss. Before our US-based program, patients had no access to outpatient endovascular treatments, resulting in treatment delays of months and higher thrombosis rates. Reducing thrombosis incidence could be especially important in low-income settings, as thrombosis management is more complex and costly than AVF angioplasties, often leading to access loss. As a limitation, US-guided angioplasty cannot address central vein stenosis and their exclusion is not always possible with Doppler US.
US-guided angioplasty programs for AVF peripheral stenosis treatment may reduce thrombosis incidence and achieve high procedural success, with minimal complications, while relying on relatively simple infrastructure.