[Free internal mammary artery for coronary bypass]

We studied 12 cases of free internal mammary artery (IMA) grafting. We used IMAs as free grafts mainly because of its shortness (6 cases 50%) and injury during dissection (4 cases 33%) and found the varicose change of saphenous vein in 5 cases (42%). Most of the grafting sites are distal parts of coronary arteries. Proximal anastomosis sites are other vein grafts (3 cases), other IMA grafts (3 cases), vein grafts interposing to the aorta (3 cases), and aorta (1 case). Patency rate of the free IMA grafts 4 weeks after operations was good (82%). Free IMA grafting is safe alternative to in situ IMA grafting when IMA grafts are short or injured and saphenous vein grafting is impossible.