Experimental Development of the Ascending Aorta-Coronary Artery Bypass

In 25 dogs ascending aorta-coronary bypass techniques were compared by use of femoral arteries in seven, internal mammary arteries in six, and reversed saphenous veins in twelve. In those animals available for long-term studies the veins were open in eight out of nine, the femoral artery grafts were open in one of four, and the internal mammary arteries were open in two of five. Histologic studies confirmed the adequacy or superiority of the vein grafts. Other conclusions drawn from these experiments were (1) that the saphenous vein bypass should originate from the ascending aorta; (2) that each bypass should have a separate aortic origin; (3) that an arrested quiet heart by means of extracorporeal circulation is necessary for satisfactory distal vein-coronary artery anastomosis; and (4) that the heart is best protected during arrest with ice slush.