The pathology of surgically excised aortocoronary saphenous vein bypass grafts

The pathologic features of 60 surgically excised failed aortocoronary saphenous vein bypass grafts from 40 patients were reviewed. In 23 cases the grafts were occluded by intimal fibrosis. In five this was associated with thrombotic occlusion of the remaining lumen. The histologic findings in some of these cases indicated that thrombosis preceded intimal fibrosis. Seventeen patients had graft failure caused by advanced arteriosclerosis. In 13 this was associated with thrombotic occlusion, often due to rupture of atheromatous plaques. The average duration of these grafts was 6--7 years compared to an average duration of 3 years for graft failure caused by occlusive intimal fibrosis, and 7 months for those associated with fibrosis and organizing thrombosis. Vein graft in the arterial circulation are susceptible to atherosclerosis; this becomes a significant problem after approximately 5 years. The pathologic changes closely resemble coronary arteriosclerosis.