Cryopreserved vein transplantation.

There have been numerous attempts to develop prosthetic conduits or utilize allograft saphenous veins for arterial bypass. This article summarizes our experimental and clinical experience with cryopreserved allograft saphenous veins. During these studies, particular attention was paid to vein donor postmortem ischemia time, vein procurement technique, and tissue storage methods. Experimental cryopreserved autograft studies demonstrated that cryopreservation of the veins does not alter subsequent graft patency, the arterialization process, blood flow, or platelet deposition in vein grafts. Endothelium-derived relaxing and contractile factors are produced by the endothelium of explanted cryopreserved autografts, and smooth muscle contractions and relaxations can be induced. In experimental cryopreserved allografts, the endothelium appears to be removed by an immune response during the first 10 days after transplantation, fibrin deposition is minimal, and re-endothelialization occurs over 6-9 months. Early clinical results using cryopreserved allograft saphenous veins are encouraging with 1-year patency rates of 79% for peripheral grafts and 86% for coronary bypass grafts.