THROMBOEMBOLISM AFTER THE FONTAN PROCEDURE AND ITS MODIFICATIONS

The frequency of thromboembolism after the Fontan procedure has not be en specifically addressed. Seventy patients underwent this operation b etween 1987 and 1992, and complete information was available on 64. Fo rty-five had a right atrium-pulmonary artery anastomosis, 17 had a tot al cavopulmonary connection, and 2 had a right atrium-right ventricle anastomosis. No patient received anticoagulants for more than 8 months postoperatively. Seven patients died in the early postoperative perio d (<30 days). Ten cases of thromboembolism were identified in the foll ow-up, which ranged from 6 to 55 months (mean follow-up, 24.5 +/- 17 m onths). They occurred 7 days to 4.5 years after the Fontan repair. Sev en thombi were on the systemic venous or pulmonary aspect of the circu lation and three, on the systemic arterial aspect. Freedom from thromb oembolism was 75% at 4 years. We conclude that thromboembolism is comm on after the Fontan procedure; it can occur several days to years post operatively; it is an important cause of morbidity; and it may partly explain late death after the Fontan operation. Our data suggest that a ll patients undergoing this procedure require long-term anticoagulant therapy.