[Adverse effect of internal thoracic artery steal on perioperative hemodynamic condition--a report of three cases].

In three patients who had suffered from perioperative hemodynamic deterioration after myocardial revascularization with an internal thoracic artery to the left anterior descending coronary artery (LAD), blood steal from the ITA into large side branches was strongly suspected. In two of them an intractable ventricular fibrillation occurred before closure of the chest. Additional insertion of saphenous vein graft to the LAD enabled them to get out of jeopardy. Postoperative angiographic studies demonstrated large pericardial branches which had several fistulous communications with the pulmonary circulation. The other suffered from anteroseptal myocardial infarction immediately after an uneventful operation. Postoperative angiography revealed an enlarged lateral costal branch which gave off four intercostal arteries. Careful and meticulous harvesting of the ITA is mandatory to avoid tragic consequences caused by its large side branches.