Factors influencing early and late outcome following the Fontan procedure in the current era. The 'Two Commandments'?

Objective: This study was undertaken to identify the factors affecting early and late outcome following the Fontan procedure in the current era. We have examined whether conventional selection criteria, the 'Ten Commandments', are still applicable in the current era.

Materials And Methods: Between January 1988 and July 2004, 406 patients underwent a modified Fontan procedure at a median age of 4.7 years (IQR, 3.8-7.1 years). The single functional ventricle was of left (n=241, 59%) or right ventricular morphology (n=163, 40%). The modified Fontan procedure was performed using an atriopulmonary connection (n=162, 40%) or total cavopulmonary connection (TCPC) involving a lateral atrial tunnel (n=50, 12%) or extracardiac conduit (n=194, 48%). They were fenestrated in 216 patients (53%).

Results: The early mortality was 4.4% (n=18) and four other patients required takedown of the Fontan circulation. On multivariable analysis, early outcome was adversely influenced by two factors (p<0.05): preoperative impaired ventricular function and elevated pulmonary artery pressures. Two risk models were constructed for early outcome based on preoperative and predictable operative variables (Model 1) and all preoperative and operative data (Model 2). Both models were calibrated across all deciles (p=0.83, p=0.25) and discriminated well. The area under the ROC curve was 0.85 and 0.89, respectively. There were 21 late deaths, 1 patient required late takedown of the Fontan circulation and 3 required orthotopic cardiac transplantation. Actuarial survival was 90+/-2%, 86+/-2% and 82+/-3% at 5, 10 and 15 years, respectively. Multivariable analysis identified that outcome was influenced by preoperatively impaired ventricular function, elevated preoperative pulmonary artery pressures and an earlier year of operation. The freedom from reintervention was 83+/-4%, 76+/-4% and 74+/-8% at 5, 10 and 15 years, respectively. Additional risk factors for reintervention were right atrial isomerism and preoperative small pulmonary artery size.

Conclusions: Late outcome of the Fontan circulation is encouraging. Ventricular morphology, surgical technique and fenestration do not appear to influence early or late outcome. Preoperatively impaired ventricular function and elevated pulmonary artery pressures have an adverse influence on both early and late outcome. Reintervention is common, with small preoperative pulmonary artery size being an additional risk factor.