Atherosclerosis of the Inferior Epigastric and Internal Mammary Arteries

Atherosclerosis of the inferior epigastric artery (IEA) and the internal mammary artery (IMA) was evaluated in 21 patients with coronary heart disease. Both arteries were used simultaneously in coronary artery bypass grafting. Histologic samples were obtained from the proximal and distal segments of IEA and from the distal segment of IMA. Morphologic findings in regard to atherosclerosis were classified semiquantitatively as normal (0), or luminal narrowing < 25% (1), 25-50% (2) or > 50% (3), or as overt atherosclerosis and calcification (4). Atherosclerosis was absent or minimal (1) in distal samples from both arteries. Only one IMA showed moderate (2) luminal atherosclerotic obstruction. Two samples from proximal IEA showed moderate (2) or severe (4) atherosclerotic changes which limited their use as free grafts. These findings suggest that atherosclerosis is minimal and comparable in distal IEA and IMA in their natural environments even in patients with coronary heart disease. The long-term effect of aortic pressure on free IEA graft is still unclear.