[Dissecting aneursym of the ascending aorta after lateral clamping for aorto-coronary by pass (author's transl)].

Four cases of dissecting aneurysm of the aorta after lateral aortic clamping for aorto-coronary bypass are described. These accidents are rare but very serious. They often occur in hypertensive patients, and sometimes an aortic wall with a low elastic fibre content is found on histology. Surgery is that of dissecting aneurysm of the ascending aorta. However the severity of these accidents should lead to routine preventive measures during all aortocoronary bypass operations, in particular aortic anastomosis of the grafts under extra-corporeal circulation.