Unveiling the relationship between Fontan fenestration closure and hemodynamic profile:a single-center study.

BACKGROUND

Decision to perform a fenestrated Fontan remains difficult to standardize, and criteria vary widely across centres.

AIM: To evaluate, in a cohort of pediatric patients undergoing total cavo-pulmonary connection (TCPC), the prognostic implications of fenestration at baseline and medium-term follow-up.

METHODS

This retrospective study included children who underwent extracardiac TCPC between 2012 and 2024. Patients were stratified by fenestration status at last follow-up. Primary endpoint was a composite of cardiovascular death, heart failure hospitalization, functional limitation, symptomatic desaturation, listing for heart transplantation, or Fontan failure. Predictors of adverse outcomes were analysed using Cox proportional hazards models and Random Survival Forest (RSF).

RESULTS

Among 109 patients, 61 (55.9%) underwent fenestrated TCPC. Of these, 29 (48%) had persistently patent fenestration, 16 (26%) had spontaneous closure, and 16 (26%) underwent transcatheter closure. Percutaneous closures occurred at a median of 3.8 years after TCPC (IQR 2.2-5.1), whereas spontaneous closure occurred earlier (0.3 years; IQR 0.2-0.9). Patients with persistent fenestration had worse pre-Fontan haemodynamical profile. Over a median follow-up of 7.54 years, 10 patients reached the primary outcome. At univariate time-dependent Cox analysis, HLHS, >moderate AV regurgitation, and persistent fenestration were associated with the primary outcome. In exploratory multivariable analysis, HLHS remained independently associated, while persistent fenestration showed borderline association. RSF analysis confirmed fenestration status as a major predictor, followed by HLHS, TPG, and AV valve regurgitation.

CONCLUSION

A persistently patent fenestration may be a marker of high risk in the Fontan population. Pre-Fontan haemodynamic characteristics influence the likelihood of fenestration closure.