Dacron vs. polytetrafluoroethylene grafts for femoropopliteal bypass: a prospective randomised multicentre trial.

OBJECTIVES: To compare the patency of PTFE (Polytetrafluoroethylene) and unsealed knitted Dacron femoro-popliteal bypasses. DESIGN: Multi-centre prospective randomised trial. MATERIALS AND METHODS: Of 203 patients randomised, 194 were included in the final analysis (103 Dacron grafts and 91 PTFE grafts). The median follow-up was 36 months (range: 6-72 months); the distal anastomosis was above-knee in 141 and below-knee in 53 cases. Univariate comparisons of patency were made by the Kaplan-Meier method, multivariate calculations on the effects of covariables by a Cox regression analysis. RESULTS: There was no difference regarding primary and secondary patency or limb salvage between Dacron and PTFE. The primary 3-year patency for Dacron grafts was 64% (95% confidence interval [C.I.] 55-74%) and for PTFE grafts 61% (C.I. 49-72%). The corresponding 3-year secondary patency was 81% (C.I. 73-89%) and 75% (C.I. 65-86%) respectively, the limb salvage rate 90% (C.I. 84-96%) and 91% (C.I. 84-97%). Upon multivariate analysis below-knee anastomosis was the principal independent predictor of primary graft failure (risk ratio 1.7 [C.I. 1.05-2.8]), impaired secondary patency was associated with infragenicular bypass (risk ratio 3.3 [C.I. 1.8-6.3]) and distal gangrene (risk ratio [C.I. 1.01-3.8]p=0.048), major amputation was independently predicted by below-knee bypass, tissue necrosis, and poor run-off index. CONCLUSIONS: PTFE and Dacron are equally suitable for femoro-popliteal bypass.