Atherosclerosis of the ascending aorta and coronary artery bypass. Pathology, clinical correlates, and operative management

Abstract

Analysis of 1735 patients who underwent coronary artery bypass grafting from January 1981 through December 1988 revealed 152 (8.8%) patients with mild (4.5%), moderate (2.2%), or severe (2.0%) atherosclerosis of the ascending aorta. Three distinct pathologic patterns were found. The prevalence of stroke in patients with the severe type of aortic disease prompted development of a new operative technique that has been used in 16 patients. It involves a "no-touch" technique of the ascending aorta whereupon the proximal saphenous vein anastomoses are performed end to side to internal mammary artery grafts. Ages ranged from 49 to 80 years (mean 68.9). The 16 patients had 62 distal artery and vein anastomoses and 26 proximal saphenous vein-internal mammary end-to-side anastomoses. Internal mammary artery free flows ranged from 130 to 420 ml/min. Two hospital deaths were unrelated to the technique. There have been no strokes or recurrences of angina. An inordinately high incidence of main left coronary disease (50%), significant carotid disease (79%), and abdominal aortic occlusive or aneurysm disease (93%) was discovered. Ascending aortic atherosclerosis must be suspected in all coronary bypass patients with associated significant carotid, abdominal aortic, and main left coronary artery disease, aortic wall irregularity on ascending aortic angiography, adhesions between the ascending aorta and its adventitia, pale appearance of the ascending aorta, and minimal bleeding of an aortic cannulation stab wound. A "no-touch" technique that avoids any manipulation of the ascending aorta and that uses the internal mammary arteries as the sole source of blood supply for coronary bypass is an effective method to prevent aortic clamp injury, "trash heart," or stroke from severe ascending aortic disease. Preoperative angiographic visualization of the ascending aorta of all patients undergoing coronary artery bypass is mandatory.