Thrombosed, ruptured atheromatous plaques in saphenous vein coronary artery bypass grafts: ten years' experience.

During the past decade the number of patients undergoing saphenous vein coronary artery bypass grafting (CABG) has increased worldwide. With a rate of late graft occlusion approximating 4% each year, the number of patients at risk for late graft occlusion continues to increase. Whereas in 1976 only 0.8% of the CABGs performed at our institution were reoperations for occluded grafts, by 1985 repeat procedures comprised 12.4% of the CABGs performed. Excised, occluded saphenous vein grafts from 52 of 119 (44%) of these patients showed thrombosis superimposed on ruptured atheromatous plaques. Ten autopsy patients showed similar lesions in their occluded grafts. The lesion was present in grafts excised as early as 3 years and as late as 14 years after bypass surgery; most occurred 5 to 10 years after implantation. Neither age at first bypass, sex, nor coronary artery bypassed permitted prediction of the occurrence of the lesion. Thrombosed, ruptured atheromatous plaque is a common, clinically significant mechanism of late graft occlusion. It is associated with recurrent symptoms that necessitate repeat revascularization and may result in death. The lesion may also be amenable to thrombolytic therapy, angioplasty, or both.