A Comparative Study of the Direct Internal Mammary-to-Coronary Artery Anastomosis and the Aortocoronary Vein Bypass Graft

Abstract

In a comparative follow-up study of the direct internal mammary-to-coronary artery anastomosis and the aortocoronary saphenous vein bypass graft, 202 dogs were observed for periods of up to 48 months. The 311 flow studies in the direct internal mammary-to-coronary artery anastomosis group showed 264 patent grafts. The average flow rates were 18.3 ml. in the right internal mammary-to-right coronary artery anastomosis group and 32.2 ml. in the left internal mammary-to-left circumflex coronary artery anastomosis group. No significant degenerative changes were detected in the internal mammary arterial wall during the four-year period; however, subintimal fibrous hyperplasia was observed in the vein wall within the 3-month postoperative period.