Free Internal Mammary Artery Graft as Arteriovenous Fistula: An Experimental Study

Abstract

To evaluate the behavior of the free internal mammary artery (IMA) graft in coronary bypass surgery an experiment was carried out in canine arteriovenous shunt position. From 6 dogs the IMA was dissected free from the right side as a naked artery and from the left side with the 2-cm-wide surrounding tissue. Three-cm-long free IMA grafts were anastomosed between the carotid artery and the contralateral external jugular vein as arteriovenous fistulas. After six months the grafts were harvested and studied by light microscopy and scanning electron microscopy (SEM). Of 12 grafts, 10 were patent. In 1 dog both free IMA grafts were thrombosed. By light microscopy intimal thickening was seen in 2 IMA grafts with the surrounding tissue, and medial fibrosis was seen in 1 naked IMA