Healing basis and surgical techniques for complete revascularization of the left ventricle using only the internal mammary arteries.

Long-term follow-up data from several leading centers concerning patients undergoing coronary artery bypass clearly demonstrate the superiority of the internal mammary artery (IMA) with patency rates of 83 to 94% at 7 to 12 years compared with the saphenous vein and its patency rates of 41 to 53%. Our experimental studies provide a biological basis for understanding this difference. Thin-walled arterial autografts undergo no histological change after being implanted in the arterial system, while venous autografts undergo major changes with an initial scattered loss of endothelium and marked thickening due to a proliferative reaction. The challenge to the cardiac surgeon is to revascularize the entire left ventricle with the IMAs. We have found this possible in most patients with advanced three-vessel disease by using both IMAs either as in situ grafts or free grafts with as many sequential anastomoses as necessary to achieve full revascularization. Our use of the term in situ refers to the graft's origin from the subclavian artery as opposed to a free IMA graft arising from another site.