Multiple Left Internal Mammary Artery-to-Pulmonary Artery Fistulae 15 Years after Coronary Artery Bypass Grafting

Left internal mammary artery (LIMA)-to-pulmonary artery fistulae rarely develop after coronary artery bypass grafting. Fewer than 30 cases of these fistulae have been reported since 1947. Nevertheless, this entity should be considered as a cause of recurrent angina after bypass surgery, in the absence of other causes. We present the case of a 67-year-old man with cardiac symptoms in whom multiple LIMA-to-pulmonary artery fistulae were found, 15 years after he had undergone coronary artery bypass grafting. The diagnosis was confirmed by means of coronary angiography with selective catheterization of the LIMA and by computed tomographic angiography of the heart. The patient underwent reoperative 2-vessel coronary artery bypass grafting and ligation of multiple fistulae; 16 months postoperatively, he was asymptomatic and doing well. In addition to reporting this case, we discuss relevant diagnostic and treatment considerations.Key words: Arteriovenous malformations/physiopathology, coronary artery bypass/adverse effects, fistula/etiology, internal mammary-coronary artery anastomosis/adverse effects, mammary arteries/surgery, myocardial ischemia/etiology, pulmonary artery/surgery, vascular fistula/complications/etiology/surgeryAs a bypass-graft conduit to the left anterior descending coronary artery (LAD), the left internal mammary artery (LIMA) is the vessel of choice because of its proven longevity and long-term patency. The formation of a LIMA-to-pulmonary artery (PA) fistula after coronary artery bypass grafting (CABG) is a rare complication: fewer than 30 reports have appeared in the medical literature.¹ We report a case of multiple LIMA-to-PA fistulae that we found 15 years after a patient had undergone CABG.