Fluid-Structure Interaction Simulation of an Intra-Atrial Fontan Connection

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Imaging

Background:

• Total cavopulmonary connection (TCPC) is a surgical procedure for single ventricle heart defects.
• Computational fluid dynamics (CFD) simulations often assume rigid walls for TCPC hemodynamics.
• The impact of wall compliance on intra-atrial TCPC hemodynamics remains unclear.

Purpose of the Study:

• To investigate the effect of wall compliance on intra-atrial TCPC hemodynamics.
• To compare fluid-structure interaction (FSI) simulations with rigid wall assumptions.
• To validate FSI models using patient-specific magnetic resonance imaging (MRI) data.

Main Methods:

• A patient-specific intra-atrial TCPC model was created using MRI data.
• Fluid-structure interaction (FSI) simulations were performed.
• Wall deformation from FSI was validated against in vivo phase-contrast MRI data.
• TCPC flow, power loss, and hepatic flow distribution (HFD) were compared between rigid and FSI models.

Main Results:

• FSI simulations showed differences in instantaneous pressure drop, power loss, and HFD compared to rigid wall models.
• No significant differences were observed in time-averaged hemodynamic metrics between the two simulation types.
• The FSI model's wall deformation correlated well with in vivo MRI data.

Conclusions:

• The use of a rigid wall assumption is supported for evaluating time-averaged intra-atrial TCPC hemodynamics.
• This finding simplifies CFD simulations for clinical applications under resting conditions.
• Accurate FSI modeling can be validated against patient-specific imaging data.