Successful coil embolization of a large right coronary artery-coronary sinus fistula causing a significant left-to-right shunt: a case report

BACKGROUND: This case reviews a challenging but successful transcatheter coil embolization of a large congenital coronary artery fistula (CAF) causing a significant left-to-right shunt. CASE SUMMARY: A 51-year-old female with no significant prior history presented with symptoms of dyspnoea and chest discomfort. Extensive evaluation revealed a large CAF between a tortuous right coronary artery (RCA) and the coronary sinus (CS) composed of three aneurysmal pseudochambers. Closure of the RCA-CS fistula was attempted through coil deployment into the fistula neck. However, due to the brisk flow through the fistula, both coils embolized into the fistula sac. An alternative location was subsequently identified on three-dimensional rendering of a computed tomography angiography scan, which revealed a sharp bend in the RCA prior to the fistula neck and distal to the posterior descending artery (PDA) takeoff. Repeat attempt at embolization was accomplished using a telescoping system to reach and occlude the targeted bend. The coil mass remained stable and angiography demonstrated reduced flow through the fistula and preserved patency of the PDA. The decreased residual flow through the fistula secondary to the initial embolization attempt likely aided the successful deployment of coils in the second and final attempt. At 1 year, the patient was doing well with resolution of her symptoms and no clinical symptoms of coronary ischaemia. DISCUSSION: We suggest that an initial unsuccessful attempt at transcatheter embolization of a CAF should not preclude subsequent attempts for closure when there exists an appropriate indication.