A meta-analysis to compare Dacron versus polytetrafluroethylene grafts for above-knee femoropopliteal artery bypass

Abstract

Surgical revascularization for lower limb ischemia remains an important component for optimization of quality of life and symptoms in patients with peripheral arterial disease. In the absence of a vein graft, prosthetic alternatives are considered. The objective of this meta-analysis was to establish which prosthetic graft, Dacron or polytetrafluroethylene (PTFE), has the better long-term patency in patients undergoing an above-knee femoropopliteal arterial bypass. This meta-analysis was performed by use of Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. An electronic search of all relevant databases was performed from 1990 to 2013 with the Medical Subject Headings "Dacron," "polytetrafluroethylene," "PTFE," "above knee," "femoropopliteal," and "bypass" combined with the Boolean operator "AND." The inclusion criteria were randomized controlled trials, use of Dacron vs PTFE prosthetic conduits, and completion of an above-knee femoropopliteal arterial bypass involving adult patients older than 18 years presenting with disabling claudication, rest pain or tissue loss, occlusion of the superficial femoral artery, and reconstitution of the above-knee popliteal artery. Whenever studies included above- and below-knee data, only the above-knee arterial bypass data were extracted and analyzed. Graft patency rates were calculated with RevMan 5.1 software provided by the Cochrane Collaboration. Ninety-one publications were reviewed. After exclusion of duplicate, nonrandomized, and alternative bypass surgery studies, eight randomized controlled trials were identified and included in the meta-analysis. Two of the included trials represented follow-up evaluation of two previous studies, and for the purpose of this analysis, the initial and follow-up studies were subsequently evaluated as one trial. In this meta-analysis, 1192 patients were assessed, including 601 Dacron and 591 PTFE above-knee lower limb arterial bypasses. Primary patency was calculated from all included studies. However, only four studies provided data to evaluate secondary patency. Mean age reported was 66 years. Although all studies described cardiovascular comorbidities and risk factors including myocardial ischemia, diabetes, hypertension, and smoking, exact patient numbers were not consistently provided. Included studies evaluated grafts from 5 to 8 mm. Although primary and secondary patency rates at 12 months were not significantly different (relative risk [RR], 0.78; P = .08, and RR, 0.84; P = .52), 24-, 36-, and 60-month primary patency rates were significantly better with Dacron compared with PTFE grafts (RR, 0.79; P = .003; RR, 0.80; P = .03; RR, 0.85; P = .02). Statistical analysis also supported higher secondary patency rates for Dacron at 24 months (RR, 0.75; P = .02) and 60 months (RR, 0.76-0.77; P = .03-.27). Although primary patency was similar between grafts (28% vs 28%; P = .12), secondary patencies were better with Dacron at 10 years (49% vs 35%; P = .01). Antiplatelet and anticoagulation protocols varied between the trials. There was no difference in amputation, overall morbidity, or mortality rates between the two surgical graft populations. Current evidence suggests that Dacron prosthetic grafts are superior to PTFE grafts in above-knee femoropopliteal arterial bypass procedures. Further randomized trials targeting standardization of confounding variables, particularly graft size and best medical therapy, are warranted.