Management of depth to achieve timely arterio-venous fistula utilization

Background Failure to achieve timely arteriovenous fistulae (AVF) utilization due to excessive depth (>6mm) remains an ongoing concern for dialysis access. This study evaluates the outcomes of radio cephalic (RCF) and brachiocephalic (BCF) fistula elevation required for access utilization. Methods A retrospective review of all patients undergoing first-time autologous access over 10 years was undertaken. RCF and BCF were analyzed, and cases of initial access failure due to depth alone were selected for study. Primary and staged brachio-basilic AVF were excluded. Outcomes of early thrombosis, Line placement, maturation (successful progression to HD), re-intervention, and functional dialysis (continuous HD for three consecutive months) were examined. Results From January 2012 to December 2022, 1733 patients (67% female, age 61±14yrs; mean ± SD) underwent autologous AVF placement. 298 (17%) patients had depth-related AVF access issues (BCF - 71% and RCF - 29%). 19% of these AVFs underwent a primary balloon-assisted maturation (BAM), and 2% had side branch coil embolization before consideration for elevation. The average time to intervention for depth was 11±4 weeks (mean ± SD) after primary creation. During elevation, side branch ligation occurred in 38% of cases, and 15% underwent intraoperative balloon-assisted maturation, The pre-elevation depth was 8.2 ± 3.1mm, and the post-elevation depth was 4.7 ± 2.9mm (mean ± SD, P= .002). Early thrombosis (<18 days) occurred in 4% of cases. There was no mortality, and 30-day MACE was 2%, with a 30-day morbidity of 5%, which was driven by wound issues. 6% of the AVFs underwent follow-up BAM within three months. Maturation of the AVFs was 74±3% vs. 72±3% (mean ± SEM; P=.58) for Elevation vs. No-Elevation groups at 24 weeks, respectively. However, there was an increase in tunneled central line placement in pre-emptive fistula patients due to the delay in maturation (17% vs. 8 %, Elevation vs. No-Elevation; P=.008). Mean successful access time of 6±3 weeks after elevation (16±4 weeks after access creation). There was a median of 2.4 secondary Interventions per year after elevation compared to a median of 2,7 secondary Interventions per year without elevation. Access functionality was 68±8% vs. 75±8% at 3 years for Elevation vs. No-Elevation, respectively (mean ± SEM; P=.25). Conclusion Elevation of deep BCF and RCF occurs late after placement but can be successfully achieved with low morbidity and satisfactory long-term functionality. It results in an increase in tunneled central line placement in pre-emptive fistula patients. Elevation is a valuable adjunct to AV fistula maturation and enhances an autologous access policy.