Hemodynamic Impact of Superior Vena XXXX Placement in the Y-Graft Fontan Connection.

@entity1 @entity33341 @entity6480
BACKGROUND: A Fontan Y-shaped graft using a commercially available aortoiliac graft has been used to connect the inferior vena @entity33341 (IVC) to the pulmonary arteries. This modification of the Fontan procedure seeks to improve hepatic flow distribution (HFD) to the lungs. However, @entity1 -specific anatomical restrictions might limit the space available for graft placement. Altering the superior vena @entity33341 ( @entity6480 ) positioning is hypothesized to provide more space for an optimal connection, avoiding caval flow collision. Computational modeling tools were used to retrospectively study the effect of @entity6480 placement on Y-graft hemodynamics. METHODS: @entity1 -specific anatomies (N  = 10 @entity1 ) and vessel flows were reconstructed from retrospective cardiac magnetic resonance (CMR) images after Fontan Y-graft completion. Alternative geometries were created using a virtual surgery environment, altering the @entity6480 position and the offset in relation to the Y-graft branches. Geometric characterization and computational fluid dynamics simulations were performed. Hemodynamic factors (power loss and HFD) were computed. RESULTS: @entity1 with a higher IVC return showed less sensitivity to @entity6480 positioning. @entity1 with low IVC flow showed varied HFD results, depending on @entity6480 location. Balanced HFD values (50% to each lung) were obtained when the @entity6480 lay completely between the Y-graft branches. The effect on power loss was @entity1 specific. CONCLUSIONS: @entity6480 positioning with respect to the Y-graft affects HFD, especially in @entity1 with lower IVC flow. Careful positioning of the @entity6480 at the time of a bidirectional Glenn (BDG) procedure based on @entity1 -specific anatomy can optimize the hemodynamics of the eventual Fontan completion.
