METHODS Between 1988 and 1995, 60 patients with complex cardiac anomalies underwent a total extracardiac cavopulmonary connection, a combination of a bidirectional cavopulmonary anastomosis with an extracardiac conduit interposition between the inferior vena cava and pulmonary arteries, except in one patient in whom direct anastomosis was possible. In 40 patients the total extracardiac cavopulmonary connection followed preliminary bidirectional cavopulmonary anastomosis, associated with a modified Damus-Kaye-Stansel anastomosis in 16. The conduits were constructed of Dacron fabric (n = 34), homografts (n = 3), and polytetrafluoroethylene (n = 22). RESULTS Total early failure rate was 15% (n = 9). Six patients died, and three more had conduit takedown owing to pulmonary artery stenosis and hypoplasia (n = 2) and severe atrioventricular valve regurgitation (n = 1). Two other patients required anastomosis revision owing to stricture. In a mean follow-up of 48 months (6 to 86 months) there were no late deaths (actuarial 5-year survival 88% +/- 4%); 52 of 54 patients are in New York Heart Association class I or II. Two patients required pulmonary artery balloon dilation or stent implantation, or both, after total extracardiac cavopulmonary connection. Late tachyarrhythmias were detected in four of 54 patients: two had sick sinus syndrome with flutter necessitating a pacemaker implantation and two had recurrent flutter (actuarial 5-year arrhythmia-free rate 92% +/- 4%). Conduit patency was evaluated by serial magnetic resonance imaging studies. Preliminary data showed a 17.8% +/- 7.6% mean reduction in conduit internal diameter during the first 6 months after total extracardiac cavopulmonary connection, with no progression over the next 5 years. CONCLUSIONS These results demonstrate that the total extracardiac cavopulmonary connection provides good early and midterm results and may reduce the prevalence of late arrhythmias in patients undergoing the Fontan operation.