Y-graft Modification to the Fontan Procedure: Increasingly Balanced Flow over Time

Abstract Objectives The use of Y-grafts for Fontan completion is hypothesized to offer more balanced hepatic flow distribution (HFD) and decreased energy losses. The purpose of this study is to evaluate the hemodynamic performance of Y-grafts over time using serial cardiac magnetic resonance (CMR) data and to compare their performance with extracardiac Fontan connections. Methods Ten Fontan patients with commercially available Y-graft connections and serial post-operative CMR data were included in this study. Patient-specific computational fluid dynamics simulations were used to estimate HFD and energy losses. Y-graft performance was compared with three extracardiac conduit (ECC) Fontan groups (n=10 for each) whose follow up times straddle the Y-graft timepoints. Results Y-graft HFD became significantly more balanced over time (deviation from 50% decreased from 18±14% to 8±8%, p=0.015). Total cavopulmonary connection (TCPC) resistance did not significantly change. Y-grafts at a three year follow up showed more balanced HFD than the ECC groups at both the earlier and later follow up times. Total cavopulmonary connection resistance was not significantly different between any Y-graft or ECC group. Conclusions Y-grafts showed significantly more balanced hepatic flow distribution over a three year follow up without an increase in TCPC resistance, and therefore may be a valuable option for Fontan completion. Additional follow up data at longer follow up times are still needed to thoroughly characterize the potential advantages of Y-graft use.