Risk Factors for Failed Fontan Procedure After Stage 2 Palliation

Background: Our aim was to evaluate the results of stage 2 palliation by means of bidirectional cavopulmonary shunt (BCPS) and to identify risk factors for failed Fontan completion. Methods: Between 1998 and 2018, BCPS was performed on 525 patients with functional single ventricle. Patient demographics, surgical data, and echocardiographic and cardiac catheterization measurements were analyzed, and outcomes after BCPS were evaluated. Results: The median age at BCPS was 4.7 months (interquartile range, 3 to 7.4). Hypoplastic left heart syndrome was the most frequent diagnosis. The median follow-up after BCPS was 3.4 years (interquartile range, 1.5 to 8.7); 407 patients underwent the Fontan procedure, 50 were waiting for Fontan completion, 47 died, 6 were considered not suitable for Fontan completion, and 15 were lost to follow-up. Of the 407 patients who underwent Fontan completion, there were 5 early deaths. Freedom from failed Fontan completion (mortality before, unsuitability for, and early mortality after the Fontan procedure) at 1, 2, and 3 years was 91.9%, 87.3%, and 86.1%, respectively. Risk factor analysis for failed Fontan completion revealed hypoplastic left heart syndrome (hazard ratio [HR] 4.1, P = .001), unbalanced atrioventricular septal defect (HR 10.1, P < .001), higher pulmonary artery pressure (HR 1.1, P = .040), and reduced ventricular function (HR 4.2, P = .001) as risks. Conclusions: Stage 2 palliation can be performed with minimal risk and provides excellent subsequent Fontan completion. Hypoplastic left heart syndrome, unbalanced atrioventricular septal defect, high pulmonary artery pressure, and reduced ventricular function at the time of BCPS were identified as risk factors for failure to successfully complete the Fontan procedure.