Use of internal mammary artery grafts for multiple coronary artery bypasses.

The internal mammary artery (IMA) is the preferred conduit for coronary artery bypass (CAB) because of its good late patency. Previously use of the IMA for CAB was limited to single anastomoses. During the last 22 months we have broadened indications for the IMA by using it for multiple distal anastomoses in 190 patients. The 166 men and 24 women ranged in age from 33 to 79 years (mean 59 years) and had an average of 2.7 diseased vessels. An average of 3.6 coronary arteries per patient were bypassed, and 65% of the distal anastomoses were made with the IMA. One hundred forty-five patients had bilateral IMA grafts and 45 patients had single IMA grafts with multiple distal anastomoses. Postoperative complications were infrequent and mortality was 0.5%. Risk of bleeding requiring reexploration was 3.4%, risk of perioperative myocardial infarction was 2.1%, and sternal complications occurred in 2.1% of patients. Eighty-seven patients consented to postoperative arteriography. All IMA grafts were open and 98.5% of distal anastomoses were patent. These good early results with the IMA support its wider use for bypass of multiple coronary arteries with a potential for improved late survival and functional results after CAB.