In Reply.—Dr Del Campo has made several observations regarding our reported experience with polytetrafluoroethylene grafts as the arterial substitute of first choice1 that deserve careful analysis. He is correct in emphasizing that our series was not randomized and therefore suffers the weakness of a retrospective review. He also states that the series was not consecutive and this deserves some explanation. Our stated objective in this review was to determine the outcome of patients undergoing femoropopliteal bypass grafting in which the decision to use polytetrafluoroethylene grafts was made preoperatively without any attempt to harvest saphenous vein. It was our hypothesis that this group of patients might do better than a corresponding group of patients in whom the decision to use polytetrafluoroethylene grafts was made after a saphenous vein was harvested and found to be of poor quality. Early in the series, not all of the surgeons in our group