Broad variation in prosthetic conduit use for femoral-popliteal bypass is not justified on the basis of contemporary outcomes favoring autologous great saphenous vein

Abstract

Background: Single-segment great saphenous vein (GSV) has been the preferred conduit for femoral-popliteal (FP) bypass, particularly for a popliteal artery target below the knee. Yet, controversy persists surrounding whether prosthetic conduit can yield comparable outcomes to GSV for FP bypass to either the above-knee (AK) or below-knee (BK) popliteal artery. We sought to analyze national variation in conduit use and to compare contemporary outcomes in FP bypass.

Methods: A retrospective review of elective FP bypass in the Vascular Quality Initiative database using single-segment GSV or polytetrafluoroethylene (PTFE) from 2003 to 2018 was performed. Variation in conduit use was examined on a regional and center level. Characteristics of the patients and operative factors were compared. Effects of conduit on 1-year outcomes were assessed using Kaplan-Meier and multivariable Cox regression analyses.

Results: Of 7430 FP bypasses performed in the Vascular Quality Initiative, 3930 (53%) used GSV and 3500 (47%) used PTFE. Conduit use differed for AK-popliteal bypass (38% GSV and 62% PTFE) and BK-popliteal bypass (67% GSV and 33% PTFE). PTFE use was inversely correlated with preoperative vein mapping among centers (ρ = -0.55; P < .001). This inverse correlation was stronger for AK-popliteal bypasses (ρ = -0.61; P < .0001) than for BK-popliteal bypasses (ρ = -0.34; P = .0004). Overall, patients undergoing FP bypass with PTFE were more likely to be older and to have multiple medical comorbidities. Operative outcomes were similar between groups, although FP bypass with GSV incurred higher rates of wound infection (P < .001) and reoperation for bleeding, thrombosis, or revision (P < .01). At 1-year follow-up, GSV patients had higher graft occlusion-free survival (83% vs 78%; P < .001) and amputation-free survival (87% vs 82%; P < .001). These differences were observed for both AK-popliteal and BK-popliteal artery subgroups. On multivariable analyses stratified by bypass target, PTFE use was independently associated with increased risk of graft occlusion (AK-popliteal: hazard ratio [HR], 1.4 [P = .002]; BK-popliteal: HR, 1.3 [P = .02]) and amputation (AK-popliteal: HR, 1.4 [P = .006]; BK-popliteal: HR, 1.6 [P < .001]) at both target levels.

Conclusions: PTFE is frequently used in FP bypass, representing two-thirds of AK-popliteal FP bypasses and one-third of BK-popliteal FP bypasses. However, PTFE use varies widely among centers. GSV was associated with higher rates of wound infection and reoperation and PTFE was associated with inferior 1-year outcomes independent of target artery level. GSV should be used for FP bypass whenever it is clinically feasible. Decreasing variation in prosthetic conduit use may be a useful quality improvement metric.

Keywords: Lower extremity bypass; Polytetrafluoroethylene; Practice variation; Saphenous vein.