Low-Grade Intimal Hyperplasia in Internal Mammary and Right Gastroepiploic Arteries as Bypass Grafts

Background. Knowledge is limited regarding the histology of the internal and right gastroepiploic arteries that have been functioning as coronary artery bypass conduits. Methods. Four internal mammary arteries, 3 right gastroepiploic arteries, and 1 saphenous vein graft that had been functioning as coronary artery bypass grafts were harvested and examined histologically in 3 male patients who had died at 19, 38, and 47 months after coronary revascularization. Results. All grafts were patent. The mean thicknesses of the intima in the proximal, middle, and distal segments were 41.0, 31.8, and 25.8 μm for the internal mammary artery and 58.0, 40.3, and 34.3 μm for the right gastroepiploic artery. The saphenous vein graft showed severe focal atherosclerosis. Conclusions. This histologic study in a small number of patients corroborates the reported excellent patency rates at medium- to long-term follow-up of the internal mammary and right gastroepiploic arteries used as coronary artery bypass grafts.