Multiblock High Order Large Eddy Simulation of Powered Fontan Hemodynamics: Towards Computational Surgery

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Computational Fluid Dynamics

Background:

• Single ventricle congenital heart defects necessitate Fontan circulation, a palliative procedure with inherent circulatory inefficiencies and long-term risks.
• Current management focuses on optimizing the Total Cavopulmonary Connection (TCPC) or employing mechanical support.
• A novel implantable pump is proposed to augment pressure within the TCPC, aiming to restore a two-ventricle-like circulation.

Purpose of the Study:

• To evaluate the hemodynamic performance of a proposed vaned impeller pump for Fontan circulation.
• To investigate the flow dynamics within a patient-specific Total Cavopulmonary Connection (TCPC) with and without the novel mechanical support.
• To assess the feasibility of using Computational Fluid Dynamics (CFD) for simulating blood flow in complex, patient-specific cardiovascular geometries.

Main Methods:

• Development of an in-house high-order Large Eddy Simulation (LES) solver coupled with an Immersed Boundary Method (IBM) for complex geometries.
• Implementation of multiblock capabilities for efficient simulation of patient-specific TCPC models.
• Performing CFD simulations of blood flow in a patient-specific TCPC, including scenarios with virtual implantation of temporary and chronic pump designs.

Main Results:

• Detailed analysis of instantaneous flow structures and hepatic flow distribution under different simulated conditions.
• Quantitative assessment of hemodynamic parameters with and without the proposed mechanical circulatory support.
• Validation of CFD as a powerful tool for evaluating novel cardiovascular device designs and patient-specific hemodynamics.

Conclusions:

• The developed CFD framework, incorporating LES and IBM, is capable of simulating complex, unsteady blood flow in patient-specific TCPC geometries.
• The proposed vaned impeller pump shows potential for augmenting pressure and improving hemodynamic efficiency in Fontan circulation.
• CFD simulations provide crucial insights for the design and optimization of mechanical circulatory support devices for single ventricle physiology.