Mid-term outcomes of Y-graft and age-matched extracardiac and lateral tunnel Fontan patients.

Abstract

Background: The bifurcated Y-graft Fontan was designed with computational fluid dynamics models that predicted reduced venous pressures, improved hepatic flow distribution, and reduced blood flow collision. Addressing these concerns was thought to improve complications associated with the traditional extracardiac and lateral tunnel techniques. However, clinical outcome data comparing the Y-graft to conventional approaches remain limited.

Methods: This retrospective cohort study evaluated patients aged 0-18 years who underwent clinical evaluation after Fontan operations between 2010 and 2023. Y-graft patients were age-matched 1:2 to extracardiac and lateral tunnel cohorts. Outcomes were assessed from the first outpatient cardiology visit at least one-year post-Fontan to the last visit within the study period. The primary outcome was a composite of death, stroke, advanced heart failure referral, or cardiac intervention (including balloon angioplasty, stenting, coiling, or fenestration). Cardiac intervention alone and surgical revision alone served as secondary outcomes.

Results: A total of 165 patients were analysed. Baseline demographics were similar across cohorts at the time of index encounter. The composite outcome occurred at comparable rates across groups (p = 0.761). Cardiac intervention rates (p = 0.873) and surgical revision rates (p = 0.378) were similar.

Conclusions: Despite the theoretical haemodynamic advantages of the Y-graft Fontan, no significant mid-term clinical benefit was observed compared with the extracardiac or lateral tunnel Fontan techniques. These findings suggest that computational fluid dynamics modelling may not fully capture the physiologic complexity of Fontan circulation, warranting reassessment of the Y-graft's continued use and further long-term outcome analysis.