Midterm Outcomes after the Modified Fontan Operation: A Single-Centre Experience

Background: Outcomes of single-ventricle patients undergoing the Fontan operation improved over the past decades. Survival into adulthood is expected. We aimed to evaluate survival and morbidity after the modified Fontan operation in a large single-center cohort.

Method: Medical records of patients undergoing modified Fontan operation between 1996 and 2018 were reviewed. Survival and freedom from heart transplantation or Fontan take-down was evaluated (primary endpoint). Freedom from Fontan operation–related complications, namely, protein losing enteropathy (PLE), plastic bronchitis (PB), arrhythmias, and thromboembolic events, served as secondary endpoint.

Results: A total of 390 patients (240 males and 150 females) were included, 251 (64.4%) had right ventricular morphology. Median age at surgery was 2.7 (IQR: 2.3–3.2) years. The interatrial lateral tunnel technique was utilized in 343 (87.9%) cases.

Median follow-up was 9.5 (IQR: 5.0–13.9) years. The primary endpoint was reached in 26 patients (death, n = 21; take-down, n = 3; transplant, n = 2). Freedom from death, transplantation, or take-down was 95 and 89% after 10 and 15 years, respectively, with no difference between ventricular morphologies (p = 0.756) or underlying diagnoses (p = 0.301). Arrhythmia requiring treatment was the most common adverse event. Freedom from arrhythmia was 91 and 81% after 10 and 15 years, respectively. Pacemaker implantation was performed in 17 patients. The rate of clinical symptomatic thromboembolic events was low (0.4 per 100 patient years). At most recent follow-up, only 44 (11.8%) patients were commenced on oral anticoagulation, the remainder received antiplatelet medication. PLE was diagnosed in 21 patients (19 alive at latest follow-up) and PB occurred in 14 patients (9 alive at latest follow-up). Complication-free survival was 81 and 70% after 10 and 15 years, respectively, with no difference between ventricular morphologies (p = 0.450) or underlying diagnoses (p = 0.240). However, compared with the remainder patients with tricuspid atresia had higher event-free survival at 15 years (84 vs. 68%, p = 0.030). The occurrence of arrhythmias after Fontan completion was associated with impaired survival (p = 0.001).

Conclusion: Midterm survival was good in a contemporary single-center Fontan cohort. There was no difference between left and right ventricular morphology with regard to survival or frequency of adverse events. Adverse events occurred in about one-third of patients during 15-year follow-up. Arrhythmic events are associated with impaired survival.

Publication History

Article published online:
12 February 2022