20 years of experience with the Fontan procedure: Risk factors for adverse outcomes.

Introduction and objectives: The Fontan procedure and the management of patients with univentricular physiology have undergone significant evolution over the past five decades. However, the long-term outcomes of these patients remain not fully understood. This study aimed to evaluate the early and long-term outcomes of patients undergoing the Fontan procedure and to identify risk factors associated with adverse clinical events.

Methods: Patients who underwent the Fontan procedure between 2004 and 2023 were included in this study. Multivariable logistic regression analysis was employed to assess risk factors for early mortality, while a Cox proportional hazards regression model was used to evaluate predictors of long-term Fontan failure.

Results: A total of 400 patients were included, with a male predominance (67.3%). Median age at the time of the Fontan procedure was 5.8 years (interquartile range: 4.1-11.0 years). The distribution of ventricular morphology was as follows: dominant right ventricle (33%), dominant left ventricle (35.75%), and two well-developed ventricles (28.75%). The early mortality rate was 5.5%. The overall survival rates at 5-, 10-, and 15-years post-Fontan surgery were 97.5%, 92.6%, and 90.0%, respectively. Multivariable analysis identified asplenia (odds ratio [OR], 10.2; 95% confidence interval [CI], 2.8-36.4; p<0.01), single-stage total cavopulmonary connection (OR, 5.3; 95% CI, 1.7-16.8; p<0.01), and prolonged cardiopulmonary bypass time (OR, 1.0; 95% CI, 1.0-1.0; p<0.01) as significant predictors of early mortality. Cox regression analysis demonstrated that heterotaxy (hazard ratio [HR], 3.5; 95% CI, 1.4-8.7; p<0.01) was an independent risk factor for late Fontan failure.

Conclusion: The staged Fontan strategy was associated with reduced early mortality but did not confer significant benefits on long-term outcomes. Patients with heterotaxy were at an increased risk of late Fontan failure, highlighting the need for tailored management strategies in this high-risk population.