Right atrial-to-pulmonary artery anastomosis (modified Fontan-Kreutzer operation) often results in substantial enlargement of the right atrium over time. Massive right atrial dilatation can cause loss of laminar flow, stasis, compression of the right pulmonary veins posteriorly, and leftward shift of the atrial septum. Some patients may develop arrhythmias related to atrial distension and multiple suture lines. Chronic elevation of the central venous pressure may cause liver dysfunction and/or protein-losing enteropathy in some patients. Some patients with atriopulmonary Fontan connections who develop a decline in functional status may benefit from conversion to a total cavopulmonary connection. Patients with significant ventricular dysfunction can usually only be treated by cardiac transplantation. However, other problems may be successfully managed by revision of the atriopulmonary Fontan connection to a total cavopulmonary anastomosis. Conversion to a total cavopulmonary connection should improve cardiac output by restoring laminar flow, by relieving compression of the right pulmonary veins, and by alleviating the leftward displacement of the atrial septum. Copyright 1998 by W.B. Saunders Company