• Congenital fistulas of the internal mammary artery to the pulmonary circulation are rare, with only 12 patients described in the world literature. Two additional patients are now described who have an associated prolapse of the mitral valve, one of whom had mitral insufficiency. In most instances, the arteriovenous fistula is essentially asymptomatic and is often discovered when a continuous murmur is heard on routine chest examination. The definitive diagnosis is made best by selective arteriography. The embryologic origin of these fistulous communications may be the maldevelopment of accessory bronchial arteries arising from the internal mammary artery. In view of the potential risks of congestive heart failure as well as proximal dilation and degeneration of the parent artery, secondary hypertension, and endocarditis, operative closure of the arteriovenous fistula is recommended.
(Arch Surg 1981;116:1265-1273)