Vein graft occlusion. Immediate and late consequences and therapeutic implications

The risks of unsuccessful aortocoronary saphenous vein bypass graft (SVBG) operations were assessed in 340 patients operated on since 1968. There were 14 operative deaths (4%) and 13 late deaths (4%) related primarily to irreversible myocardial failure or unbypassed coronary obstructions. A total of 205 patients with 320 grafts were studied an average of 7 mths postoperatively. 81% of grafts were patent, and 88% of patients had at least one patent graft. Fifty two patients (25%) with one or more occluded grafts were analyzed in detail. Despite occlusion of 62 grafts, 35 of 62 coronary arteries (56%) with occluded grafts were unchanged angiographically; 20 (33%) were occluded, and 7 (11%) were stenotic. Eight of 52 patients (15%) with occluded grafts had postoperative infarction. In 31 patients with occluded grafts and postoperative left ventricular (LV) function studies, new LV asynergy with a rise in LV end diastolic pressure was seen in one, and 2 others had a substantial decline in ejection fraction and/or a rise in LV end diastolic pressure. It is concluded that when SVBG occlude, injury to grafted arteries, postoperative infarction, or LV functional deterioration is uncommon. The major threats to patients having SVBG operations are irreversible myocardial damage and unbypassed coronary obstructions.