Y-graft modification to the Fontan procedure: Increasingly balanced flow over time

Area of Science:

• Pediatric Cardiology
• Cardiovascular Surgery
• Biomedical Engineering

Background:

• The Fontan procedure is a palliative surgery for complex congenital heart defects.
• Optimizing hemodynamics after Fontan completion is crucial for long-term outcomes.
• Y-grafts are a newer alternative to extracardiac conduits for Fontan connections.

Purpose of the Study:

• To evaluate the long-term hemodynamic performance of Y-grafts in Fontan patients.
• To compare hepatic flow distribution (HFD) and energy losses between Y-grafts and extracardiac conduits.
• To assess changes in total cavopulmonary connection resistance with Y-graft use.

Main Methods:

• Utilized serial cardiac magnetic resonance imaging data from 10 Fontan patients with Y-grafts.
• Employed patient-specific computational fluid dynamics (CFD) simulations to analyze HFD and energy losses.
• Compared Y-graft performance to three extracardiac conduit Fontan groups (n=10 each) at various follow-up times.

Main Results:

• Y-graft HFD significantly improved, becoming more balanced over a 3-year follow-up (deviation from 50% decreased from 18% ± 14% to 8% ± 8%; P=.015).
• Total cavopulmonary connection resistance remained unchanged and was not significantly different between Y-graft and extracardiac conduit groups.
• At 3-year follow-up, Y-grafts demonstrated more balanced HFD compared to extracardiac conduits at all follow-up intervals.

Conclusions:

• Y-grafts offer significantly more balanced HFD over a 3-year period post-Fontan completion without increasing total cavopulmonary connection resistance.
• Y-grafts represent a potentially valuable surgical option for Fontan completion.
• Further long-term follow-up studies are necessary to fully elucidate the advantages of Y-graft utilization.