There is some evidence that a vein cuff at the distal anastomosis site improves primary graft patency rates for below knee PTFE graft, but this does not reduce the risk of limb loss. Evidence for this beneficial effect of vein cuffed PTFE grafts is weak and based on an underpowered trial. Pre-cuffed PTFE grafts have comparable patency and limb salvage rates to vein cuff PTFE grafts. The use of spliced veins improved secondary patency but this did not translate into improved limb salvage. The use of an AVF alone showed no added benefits. A large study with a specific focus on below knee vein cuff prosthetic grafts, including PTFE, is required.
PTFE bypass to below-knee arteries: distal vein collar or not? A prospective randomised multicentre study.
Patency and limb salvage after synthetic bypass to the arteries below-knee are inferior to that which can be achieved with autologous vein. Use of a vein collar at the distal anastomosis has been suggested to improve patency and limb salvage, a problem that is analysed in this randomised clinical study.
                Patients with critical limb ischaemia undergoing polytetrafluoroethylene (PTFE) bypass to below-knee arteries were randomly either assigned a vein collar or not in two groups - bypass to the popliteal artery below-knee (femoro-popliteal below-knee (FemPopBK)) and more distal bypass (femoro-distal bypass (FemDist)). Follow-up was scheduled until amputation, death or at most 5 years, whichever event occurred first.
                In the FemPopBK and in the FemDist groups, 115/202 and 72/150 were randomised to have a vein collar, respectively. Information was available for 345 of 352 randomised patients (98%). At 3 years, primary patency was 26% (95% confidence interval (CI) 18-38) with a vein collar and 43 (33-58) without a vein collar for femoro-popliteal bypass and 20 (11-38), and 17 (9-33) for femoro-distal bypass, respectively. The corresponding figures for limb salvage were 64 (54-75) and 61 (50-74) for femoro-popliteal bypass, and 59 (46-76) and 44 (32-61) for femoro-distal bypass with and without a vein collar, respectively. Log-rank-test for the whole Kaplan-Meier life table curve showed no statistically significant differences with or without vein collar primary patency: p = 0.0853, p = 0.228; secondary patency: p = 0.317, p = 0.280; limb salvage: p = 0.757, p = 0.187 for FemPopBK and FemDist, respectively. The use of a vein collar did not influence patency or limb salvage.
                This study failed to show any benefit for vein collar with PTFE bypass to a below-knee artery.
                Copyright (c) 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.