Factors influencing perioperative morbidity during palliation of the univentricular heart

Background. The modified Fontan procedure has become the treatment of choice for patients born with a univentricular heart. Although the operative mortality has steadily decreased in recent years, the hospital stay is still prolonged in many patients due to fluid retention and pleural effusions. Methods. We retrospectively analyzed subsets of patients undergoing the bidirectional cavopulmonary shunt (BDCPS) and modified Fontan procedure in an attempt to define factors influencing operative mortality and morbidity. Results. Multivariate analysis of 64 patients undergoing BDCPS revealed that age 6 months or less, concomitant operation, mean pulmonary pressure of 15 mm Hg or less, and mean pulmonary artery ratio of 1.8:1 or less were not statistically significant indicators of risk. Abnormal pulmonary artery architecture was a significant predictor of early and late death (p less than or equal to 0.01). Retrospective analysis of 71 patients undergoing the modified Fontan procedure revealed no significant relationship between duration of pleural effusions and age at operation, pre-operative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, or prior BDCPS. Patients with important aortopulmonary collateral vessels defined by angiography had prolonged pleural drainage. Selective use of the total extracardiac conduit and the fenestrated Fontan resulted in low overall mortality with no statistical differences between subsets of patients undergoing different modifications of the Fontan procedure. Conclusions. These data indicate that the operative risk for BDCPS or modified Fontan procedure is quite low if a procedure appropriate for the patient is selected. Abnormal pulmonary artery architecture is an important risk factor for death after the BDCPS. Aortopulmonary collateral vessels are associated with fluid retention and pleural effusions after a modified Fontan procedure. Important aortopulmonary collateral vessels should be occluded before or during the modified Fontan procedure.