Graft patency in coronary bypass surgery.

A total of 514 vein bypass grafts and 49 internal mammary (IMA) grafts in 328 patients were studied after operation. Forty-two vein bypass grafts were performed without the use of a pump oxygenator, with a patency rate of 52%. When a pump oxygenator was used, the patency rate for vein bypass grafts was 78%. Patency rates for IMA grafts were 70% and 86%, respectively. In a small group of patients, endarterectomy with vein bypass grafts resulted in a patency rate of 59% in the right coronary artery, 88% in the left anterior descending coronary artery, and 74% in the circumflex artery. Except for the right coronary artery, these results compare favorably with those from vein bypass graft patency without endarterectomy. On the basis of these findings, insertion of bypass grafts into the coronary arteries without the use of a pump oxygenator cannot be recommended, unless the technique employed can be shown to produce graft patency rates comparable to those resulting from grafts done with the use of a pump oxygenator. Endarterectomy to the left anterior descending and circumflex arteries would not appear to affect vein bypass graft patency.