299 - Investigating Ultrasound Predictors of EndoAVF Outcomes

Purpose: Endovascular arteriovenous fistulas (endoAVFs) have emerged as a minimally invasive alternative to surgical arteriovenous fistulas for hemodialysis access, offering shorter maturation times and fewer interventions {1-4}. Current ultrasound (US) screening criteria are based on device dimensions rather than validated clinical predictors. The predictive value of preoperative US characteristics for endoAVF outcomes remains largely unexplored. Thus, in this study we investigate how specific preoperative US features correlate with outcomes of endoAVFs created by the WavelinQ device.

Materials and Methods: This is a retrospective cohort study of adults who underwent WavelinQ endoAVF procedures at the University of Pittsburgh Medical Center since 2018. Patients under 18 or lacking both pre- and post-operative US imaging were excluded. Data collection focused on preoperative US features, such as vessel diameters, flow rates, demographics, clinical characteristics, and post-procedural outcomes. Outcomes of interest include time to fistula maturation, number of secondary interventions, and flow rate at maturation. Statistical analysis using Pearson correlations assessed associations between US features and outcomes.

Results: Initial data was collected for 30 patients. The majority were male (60%), and mean age at procedure was 59.5 years. The average time to maturation was 34.27 days, with mean post-maturation flow rate of 707.83 mL/min. Patients required an average of 0.77 interventions for maturation and 1.63 total procedures, both maturation and maintenance, in the first year. No serious adverse events were reported. Linear regression showed that increasing depth of proximal cephalic vein correlated with longer time to maturation (p=0.007), and greater diameter of lateral brachial vein was associated with lower flow rates at maturation (p=0.01). Other pre-operative US factors did not correlate strongly with outcomes.

Conclusion: Preliminary data shows endoAVF is associated with rapid maturation and a low rate of serious adverse events in our cohort. Depth of the proximal cephalic vein and diameter of the lateral brachial vein may correlate with time to maturation and flow rate, while other traditional US screening factors did not show strong correlation. Identifying predictors of endoAVF outcomes may inform patient selection, enhance preprocedural planning, and reduce secondary interventions. This study represents a step toward developing evidence-based guidelines for US-based assessment prior to endoAVF creation.