Overview of different modifications of Fontan palliation in patients with a univentricular heart. In patients with Fontan-type repair, the systemic venous return is re-directed to the pulmonary circulation (without a subpulmonary ventricle). Over time, several modifications have been developed. The “classic” Fontan repair: direct connection between right atrium and pulmonary artery. In total cavopulmonary anastomosis (TCPC), a connection is made between the superior and inferior vena cava and the right pulmonary artery. The superior vena cava is anastomosed directly end-to-side with the pulmonary artery, the connection to the inferior vena cava can be established either via a lateral tunnel within the right atrium or via an extracardiac conduit. TCPC is the preferred procedure because of better hemodynamics, a lower incidence of arrhythmias, and better long-term survival. Typical problems in the long term are ventricular dysfunction, intraatrial thrombi, and a proneness to arrhythmias. These problems are encountered in particular after the “classic” Fontan repair