PATHOLOGY OF INTERNAL MAMMARY ARTERIES USED AS BYPASS GRAFTS

We describe four patients in whom internal mammary arteries used as co ronary artery bypass grafts demonstrated pathologic changes that could affect long-term patency. Two grafts showed evidence of arteritis, an d two showed degenerative changes as seen in so-called cystic medial n ecrosis. In one of these two cases intraoperative dissection of the in ternal mammary artery and aorta occurred. Aside from the rare occurren ce of atherosclerosis, we have found no previous reports of systemic v ascular disease affecting this artery. (C) 1997 by Elsevier Science In c.