Comparison between autogenous saphenous vein and heparin-bonded expanded polytetrafluoroethylene for below-the-knee popliteal and tibial bypasses in patients with critical limb ischemia

Objective To retrospectively compare the outcomes of heparin bonded expanded polytetrafluoroethylene (HePTFE) and autogenous saphenous vein (ASV) in patients undergoing below-knee (BK) femoro-popliteal bypass for critical limb ischemia (CLI) Methods From January 2002 to December 2022, 625 consecutive femoro-popliteal bypasses were performed at our Institution. In 337 cases a BK intervention was performed in patients with CLI, 145 with the ASV and 192 with a HePTFE graft. In the same period of time 39 above-the-knee HePTFE bypasses in patients with CLI were performed, and they were excluded from the analysis. Perioperative outcomes were analysed in terms of mortality, thrombosis, reinterventions, and early amputation and compared with χ2 test. Follow-up outcomes were analysed in terms of survival, primary patency, secondary patency, limb salvage, and amputation-free survival with Kaplan-Meier curves and compared with log rank test. The analysis of follow-up results concluded in September 2023. Results Baseline characteristics of the HePTFE and ASV patients were similar in the two groups. There were no differences in terms of perioperative outcomes. The median duration of follow-up was 37 months and the mean follow-up index (defined as the ratio between the investigated follow-up period and the theoretically possible follow-up period up to September 2023) was 0.7 (range 0.03-1). The estimated 10-year survival rate was 46% in the HePTFE group and 49.7% in the ASV group (p=0.8, log rank 0.07). Primary patency rates at 10 years were 26% in the HePTFE group and 36% in the ASV group (p=0.1, log rank 2.2). Secondary patency rates at 10 years were 29% (SE 0.06) and 36.6% (SE 0.08), respectively (p=0.7, log rank 0.08). Amputation-free survival rates at 10 years were 38% (SE 0.06) and 40.5% (SE 0.05), respectively (p=0.9, log rank 0.09). The presence of coronary artery disease, of ulcers or gangrene and the need for tibial anastomosis were independent predictors of death and/or amputation during follow-up. Conclusions HePTFE demonstrated comparable 10-year outcomes to those achieved with ASV in patients with CLI undergoing below-knee or tibial bypass. Satisfactory results were observed in both groups in the below-knee setting, whereas in the tibial artery the performance of both materials was extremely poor.