Fontan Circulation

Abstract

The Fontan procedure was initially suggested as a treatment for patients with tricuspid atresia. Since its introduction the application of this innovative surgical approach has expanded to include patients with single ventricle physiology secondary to a variety of anatomic disorders including hypoplastic left heart syndrome, double inlet or other single left ventricle, pulmonary atresia with intact ventricular septum, unbalanced atrioventricular septal defects, complex heterotaxy syndromes, and others. There has also been extensive evolution of the surgical approach. Currently two types of total cavopulmonary anastomoses, the lateral tunnel and extracardiac conduit modifications, are the most commonly employed modifications, as they appear to reduce the energy loss within the Fontan circuit and reduce the long-term risk of arrhythmias. Older patients with historic anatomic Fontan modifications including right atrial to pulmonary artery or right atrial to right ventricular anastomoses, with or without interposed valves within the Fontan circuit, are still encountered. Fontan physiology can have a dramatic upon the cardiopulmonary response to exercise and exercise testing can provide important information regarding a patient’s clinical status.