Surgical treatment of complex congenital heart disease with modified Fontan procedure.

Between October 1973 and mid-January 1987, 500 patients underwent a modified Fontan operation at the Mayo Clinic. This included 163 patients with tricuspid atresia, 154 patients with double inlet ventricle, and 183 patients with other complex single ventricle malformations. There have been 80 hospital deaths (16%). In the last 5 years there have been 39 deaths (11.7%). Lowest mortality was seen in patients with tricuspid atresia (11% overall, 5.8% last 5 years) and highest mortality was seen in patients with complex lesions. Younger age at operation, elevated pulmonary artery pressure, elevated right atrial pressure following operation, and prolonged bypass times were significant risk factors. The modified Fontan procedure provides effective palliation for complex congenital cardiac anomalies which have no other satisfactory treatment. Criteria for operability have been extended beyond those originally proposed for this operation. The operative mortality continues to decline with increasing experience, late results are good, and longevity appears to be increased. The Fontan operation has been increasingly utilized as the definitive surgical palliation for patients with functional single ventricle. At the Mayo Clinic, over 600 patients have undergone a modified Fontan operation since our first case in October 1973. This presentation gives the results of the first 500 cases and describes the various preoperative and perioperative factors which may influence a successful outcome.