Tunnel Transposition versus Lipectomy for Second-Stage Superficialization of Deep Brachiocephalic Arteriovenous...

Deeply located arteriovenous fistulas (AVFs) pose a major challenge in hemodialysis access, especially in obese patients, where the cephalic vein lies beyond the optimal cannulation depth. Second-stage superficialization techniques such as tunnel transposition and lipectomy are often required, yet comparative data on their effectiveness remain limited. To compare the clinical outcomes of tunnel transposition versus lipectomy for second-stage superficialization of deep brachiocephalic AVFs.

This multicenter retrospective study included 127 patients with mature brachiocephalic AVFs and cephalic veins located >6 mm from the skin surface, who underwent superficialization between January 2020 and May 2024. Patients were assigned to tunnel transposition (n = 69) or lipectomy (n = 58) groups. Outcomes included technical success, time to cannulation, complication rates, and long-term patency. Data were analyzed using t-tests, chi-squared tests, and Kaplan-Meier survival analysis.

Demographics and comorbidities were comparable between groups. The mean post superficialization vein depth was lower in the tunnel group (2.48 ± 0.34 mm) compared to the lipectomy group (2.71 ± 0.92 mm), though not statistically significant (P = 0.057). Difficult cannulation occurred significantly more often in the lipectomy group (10.34% vs. 1.45%; P = 0.047). Other complications, including hematoma, infection, thrombosis, and postoperative steal syndrome, were similar. Primary and secondary patency rates up to 24 months showed no significant difference between groups.

Tunnel transposition and lipectomy are both effective for superficializing deep brachiocephalic AVFs. However, tunnel transposition may reduce the rate of difficult cannulation and may be preferred in patients with severe vein depth or scarring.