Transcatheter treatment of an unusual coronary arteriovenous malformation with a fistulous sac in the interventricular septum

Coronary artery fistula (CAF) is a rare congenital anomaly with a reported incidence of 0.2%–0.6%. There is a wide variation in the clinical presentation depending on the size and the site of the fistula. Transcatheter closure is currently the treatment of choice in these patients. We report a case of CAF with an unusually large fistulous sac within the interventricular septum. The fistula had connections with all the three major coronary arteries, namely, left anterior descending (LAD), left circumflex, and right coronary arteries but did not have any exit resulting in to and fro movement of blood within the sac and the feeding vessels. The patient was managed successfully by transcatheter coil embolization.