Figure 1 Evolution of PTFE grafts. Conventional Polytetrafluoroethylene Grafts Multiple reports and clinical studies have shown PTFE grafts to be an adequate alternative conduit for peripheral bypass operations. In a randomized study by Johnson and Lee, 265 patients underwent a femoral to above-the-knee popliteal artery bypass using Inhibitors,research,lifescience,medical a supported PTFE graft.1 The cumulative assisted primary patency rates at 2 and 5 years were 69% and 39%, respectively. Eagleton and associates performed 74 femoral to infrapopliteal artery bypass operations for limb salvage using with expanded
PTFE (ePTFE).2 The primary patency, assisted primary patency, and secondary patency rates at 24 months were 40±10%, 48±11%, and 52±11%, respectively. Limb salvage was successful in 62±10%. Forty-six percent of bypasses were performed with a distal arteriovenous fistula, 35% with an end-to-side distal anastomosis, and 19% with a vein patch distal anastomosis. The patency of ePTFE Inhibitors,research,lifescience,medical as a femoropopliteal bypass alternative was evaluated in a prospective randomized trial that compared it to AGSV. The study enrolled 49
patients with occlusion of the superficial femoral artery and limb threatening ischemia. At 54-month follow-up, the patency rate for the ePTFE group was 37% as compared to 70% for the patients who had AGSV. The study concluded that AGSV is far superior to PTFE.3 In a study by Inhibitors,research,lifescience,medical Bergan and colleagues, 446 femoral Inhibitors,research,lifescience,medical distal reconstructions were performed.4 Patients were divided into groups depending on whether the distal insertion site was the popliteal or infrapopliteal artery, and patients received a randomized vein or PTFE graft or an obligatory PTFE graft. The 30-month patency for randomized AGSV bypass
to infrapopliteal arteries was significantly better than the patency of randomized or obligatory PTFE graft to the same level. Inhibitors,research,lifescience,medical In contrast, another study used PTFE only when AGSV was unsuitable or not available. The cumulative patency rates at 30 months were similar at 54% for AGSV and 45% for PTFE. The authors concluded that PTFE is a suitable alternative when AGSV is unavailable.5 The creation of a distal arteriovenous Idarubicin fistula is an attempt to improve graft Digestive enzyme patency results of prosthetic bypasses to infrapopliteal arteries. Ascer and colleagues performed this technique with an adjunct vein interposition graft at the distal anastomosis to improve compliance mismatch.6 Their cumulative 3-year assisted primary patency was between 62% and 78%. The 3-year limb salvage rate was 78%. However, others have shown that creating an arteriovenous fistula at the distal anastomotic site of a tibial bypass augments flow only in the postoperative period without added effectiveness or graft patency.7 The interposition of a venous segment at the distal anastomosis has been advocated to improve the results of prosthetic grafts to tibial arteries.