Prospective randomized study of carbon-impregnated polytetrafluoroethylene grafts for below-knee popliteal and distal bypass: Results at 2 years

The purpose of this prospective randomized multicenter study is to compare patency for a new carbon-impregnated polytetrafluoroethylene (PTFE) graft and standard PTFE grafts. One hundred and sixty patients presenting severe chronic ischemia of the lower extremity were recruited at 17 centers of the French Association Universitaire de Recherche en Chirurgie. Eighty-one carbon-impregnated graft and 79 standard grafts were implanted. The procedure consisted of below-knee femoropopliteal bypass in 83 cases and femorodistal bypass in 77 cases. The minimum duration of the follow-up period was 2 years. Twenty-four patients died during the study. The actuarial primary patency rate, actuarial secondary patency rate, and limb salvage rate were 45%, 53%, and 57% respectively in the carbon-impregnated PTFE group and 35%, 36%, and 47% respectively in the standard PTFE group. The carbon-impregnated graft appeared to achieve better patency than the standard graft but the difference was not statistically significant. Since there was no difference up to 12 months, the study will be continued to determine if further follow-up confirms these findings. In this study we also assessed factors contributing to patency of below-knee prosthetic bypass grafts. Only two factors had a significant influence on patency, i.e., ankle/arm pressure difference greater than 0.25 as opposed to ankle/arm pressure difference less than 0.25 (p < 0.01) and below-knee femoropopliteal bypass as opposed to femorodistal bypass (p < 0.001).