Morphology of saphenous vein-coronary artery bypass grafts: Seven to 116 months after surgery.

Morphologic changes in saphenous vein-coronary artery bypass grafts in 24 cases (51 grafts) seven to 116 months after surgery were studied. Four pathologic changes were found (1) Fibrous cord lesions were present that represented early postoperative thrombotic occlusion and organization. (2) Diffuse intimal thickening was present in all grafts maintaining long-term patency. (3) Atherosclerosis identified as intimal foam cell accumulation or frank plaques was found only in cases 39 or more months postoperative and was present in 79% of such cases (71% of the vein grafts). (4) Late vein thrombosis was found in three cases and was the presumed cause of death. We concluded that atherosclerosis occurs with a high incidence in vein grafts after three years, and plaque rupture with thrombosis can be a cause for vein occlusion.