Histologic changes in saphenous vein aorta-coronary bypass grafts: The effect of the angle of the aortic anastomosis

Abstract

Thirteen dogs were subjected to bypass grafting from the aorta to the left circumflex coronary artery with the saphenous vein to determine whether the angle of insertion of the saphenous vein into the aorta influences the functional and histologic fate of the grafts. The angle of the aortic anastomosis was obtuse in 6 dogs, acute in 5, and perpendicular in 2. Histologic examination of all 13 grafts 6 to 19 months (mean 9.4) postoperatively showed fibrous intimal proliferative lesions of variable severity along the entire length of the grafts, occasionally with extension into the native coronary arteries. Loss of medical smooth muscle and adventitial fibrosis also occurred in all 13 grafts. The extent and severity of these changes, however, were not related to the angle aortic anastomosis.