Endothelial hypoxia induction of atherosclerosis: an explanation of patency rates for internal mammary artery and other coronary artery bypass grafts.

The major etiological factors of atherosclerosis are reviewed and the case strengthened for endothelial hypoxia being the major initiator. Hypoxia is also shown to be the major cause of coronary artery bypass graft occlusions. The pathophysiological differences between pedicle and free arterial grafts and venous grafts are discussed. Arguments are presented to explain why pedicle internal mammary artery grafts have longer lasting a patency then saphenous vein grafts. It is proposed that free grafts using other systemic arteries should also give very acceptable results and may, in certain circumstances, be desirable over pedicle internal mammary artery grafts. The differences between single, Y and sequential grafts are also discussed to explain differences in patency rates.