Current status of cryopreserved saphenous vein homografts

The lack of suitable autogenous tissue and the easy availability of cryopreserved allograft veins have recently led to increased utilization of allograft bypasses. Improved methods of cryopreservation have been shown to maintain integrity of the endothelial and smooth muscle cell layers prior to implantation, increasing enthusiasm for the vein bank. However, after implantation, immune reactions result in eventual cell death and fibrosis of the conduit, with poor long-term patency. Attempts at modification of the immune response are preliminary and suggest a potential for improved patency. However, long-term patency remains poor, with only 19 to 42% of grafts patent at 2 years. Current use of the cryopreserved allograft vein should be limited to distal bypass for limb salvage in the absence of suitable autogenous tissue or revascularization for limb-threatening ischemia in an infected field in the absence of suitable autogenous tissue.