Free Internal Mammary Artery as Canine Coronary Artery Bypass Graft

Abstract

From 8 dogs both internal mam mary arteries (IMA) were harvested: the right IMA as a naked artery with out surrounding tissue and the left IMA with 2-cm-wide surrounding tis sue. Both free IMA grafts were anas tomosed to the proximal end of the left IMA one after another and then to the left anterior descending coro nary artery. At six months the free IMA grafts were harvested and stud ied by light microscopy and scanning electron microscopy (SEM). Six dogs lived the period of six months and all free IMA grafts were patent at that time. In the histologic study 3 grafts were graded as normal and intimal thickening was seen in 8 cases. The endothelial cells were covering the lu minal surface of every free IMA graft in SEM, although some degeneration was seen. This study showed that free IMA grafts maintain their patency well and the method of the dissection of the IMAs did not have any effect on the results.