Long term evaluation of allogenic veins as arterial grafts.

Ten pairs of mongrel dogs had bilateral femoral artery reconstruction using the femoral veins from the other of each pair. Four grafts failed in the first two weeks and 16 grafts failed in pairs within two to four weeks of each other up to 15 months. Five dogs died with patent grafts between 15 and 42 months and five dogs were sacrificed at 42 months with patent grafts. Aneurysmal degeneration did not occur. Normal architecture of the vein was destroyed by fibrous replacement, but a few smooth muscle cells and adventitial elastic fibers persisted. Gross and microscopic mural thrombi were present in half the grafts indicating continued endothelial instability at 42 months. Osseous metaplasia was found in five grafts. Allogenic vein is an acceptable substitute when autogenous vein is lacking for femorotibial bypass and urgent femoropopliteal bypass.