Internal mammary arteriovenous fistula after sternotomy

A patient who had undergone coronary artery bypass surgery was found to have a continuous murmur two weeks postoperatively. The diagnosis of internal mammary arteriovenous fistula was made by arteriography, which ruled out a more serious complication involving a saphenous vein to coronary artery anastomosis. The fistula was approached through the intercostal spaces above and below and ligated without difficulty. These are rare occurrences, usually asymptomatic, and are treated by ligation or ligation and excision. The etiology was thought to be closure of the median sternotomy incision with parasternal wires.