(IP197) Maintenance of femoro-tibial bypass patency through a strict follow-up protocol

Objectives: Femoro-tibial bypass for critical limb-threatening ischemia(CLTI) is a technically demanding intervention. Despite optimal intraoperative technical results, bypass patency can be negatively affected by vein hyperplasia and several studies have highlighted the needing of continuous surveillance to maintain patency, however recent data are scarcely available. The present study aims to evaluate the efficacy of a strict duplex-ultrasound (DUS) follow-up protocol for maintaining bypass patency in the endovascular era.

Methods: All consecutive patients treated with femoro-tibial bypass were prospectively collected from 2016 to 2024 into a dedicated database, evaluating clinical, anatomical, surgical characteristics, and medical therapies. Patients included in the study were treated for CLTI with vein bypasses from the femoral artery(common or superficial) with distal anastomosis to tibial (posterior/anterior/peroneal) or foot arteries. Bypasses were generally performed with an ex-situ devalvulated great saphenous vein. After the intervention, patients were maintained on oral anticoagulant therapy. Follow-up was performed in a dedicated DUS vascular laboratory every 3 months during the first year after the intervention and every six months thereafter. The primary endpoints were to evaluate primary patency (PP), and the rate of stenosis identified and treated during follow-up to increase assisted and secondary patency (AP, SP).

Results: During the study period, a total of 256 bypasses in 238 patients were considered. The patients' mean age was 74±8 years, with 78% male, 62% diabetic, and 13% on dialysis. Composite autologous vein bypass was performed in 15% of cases; the distal anastomosis was performed in 77% to tibial and 33% to foot arteries. The mean follow-up was 42±32 months, and the 5-year primary patency rate for the entire study group was 54±4%. During follow-up, 25(10%) bypass stenoses were identified and treated with endovascular angioplasty in 20(80%) cases and surgical autologous vein interposition in 5(20%). Notably, 80% of stenoses were identified and treated during the first year of follow-up. Patients submitted to redo intervention had a significantly higher AP and SP at 5 years (62±8% and 68±4%, respectively,P=.02). Diabetes mellitus and age < 75 years were identified as risk factors for vein stenosis during follow-up (Odds ratio (OR): 2.9, 95% confidence interval (CI): 1.1–9.3, P=.05; and OR: 5.4, 95% CI:1.2–28, P=.04,respectively). The overall 5-year limb-salvage rate was 81±4%.

Conclusions: A strict follow-up protocol allows to detect a not negligible rate of stenoses amenable to correction, particularly during the first year, with a significant improvement of bypass patency. Most reinterventions can be performed endovascularly.