Initial Experience With Sequential Internal Mammary Artery Bypass Grafts to the Left Anterior Descending and Left Anterior Descending Diagonal Coronary Arteries

Early patency and late patency have consistently been better with single internal mammary artery grafts than with saphenous vein conduits. To determine the efficacy of these two types of grafts in sequential anastomoses, we performed sequential anastomoses of the left internal mammary artery to the left anterior descending and diagonal coronary arteries in 40 patients and compared the results with those in 58 patients who received sequential saphenous vein grafts. Treatment with dipyridamole (starting 48 hours before operation) and aspirin (added 7 hours after operation) was given to the 40 patients with internal mammary artery grafts and to 32 of the 58 patients in the saphenous vein group. After the bypass procedure, mean blood flows were as follows: 68 ml/min in patients with internal mammary artery grafts, 73 ml/min in patients who received saphenous vein grafts and a placebo, and 99 ml/min in those who received saphenous vein grafts, aspirin, and dipyridamole. Early patency of sequential internal mammary artery grafts to the diagonal and left anterior descending coronary arteries was comparable to that of sequential saphenous vein grafts. Because a substantial late reduction in patency has been noted in sequential saphenous vein grafts, sequential internal mammary artery grafts may be the preferred conduit for coronary artery revascularization.