Catheter Closure of Coronary Artery Fistula

Abstract

Coronary artery fistula (CAF) is a direct communication of a coronary artery to any one of the cardiac chambers, systemic or pulmonary veins, or pulmonary artery bypassing the capillary network. Although most of the patients remain asymptomatic, some of them may present with heart failure, angina, myocardial infarction, arrhythmias, and sudden death. Rarely, infective endarteritis and rupture of the aneurysmal fistulous tract have been reported. Transcatheter closure (TCC) of CAF is indicated if the patient is symptomatic, left-to-right shunt is >1.5:1, or there is a chance of the patient developing one of the complications. Although TCC can be done at any age, it is safer in children weighing more than 5 kg. Preprocedural imaging with CT angiogram is extremely helpful in planning the procedure in adolescents and adults and therefore is highly recommended. However, it has significant limitations in children due to high heart rate and breathing and motion artifacts. General anesthesia is preferred in children, while local anesthesia with sedation is advisable in adults undergoing TCC. The CAF can be closed via transarterial or transvenous route depending on the anatomy of the fistula. Delineation of the fistula during the procedure can be enhanced using balloon occlusion angiography. Distal balloon occlusion also helps in determining whether closure of the fistula would result in myocardial ischemia. Coils, detachable balloons, vascular plugs, and duct occluder are most commonly used for closing the fistula. Although the success rate is very high (>95 %), the procedure is not free from complications such as thromboembolism, air embolism, coronary artery dissection, arrhythmias, and very rarely death. All the patients need a serial follow-up to evaluate occurrence of ischemia due to retrograde propagation of thrombus in the native vessel. In order to prevent this, the majority of them receive antiplatelets and/or anticoagulants.