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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Aged, Aged, 80 and over, Anastomosis, Surgical, Angiography, Blood Vessel Prosthesis, Female, Femoral Artery, Follow-Up Studies, Humans, Ischemia, Leg, Male, Polytetrafluoroethylene, Popliteal Artery, Prospective Studies, Saphenous Vein, Tibial Arteries, Transplantation, Autologous, Treatment Outcome, Ultrasonography, Doppler, Duplex.
user
PTFE bypass to below-knee arteries: distal vein collar or not? Context: 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.
assistant
This study failed to show any benefit for vein collar with PTFE bypass to a below-knee artery.