MRI-Based Patient-Specific Computational Modeling of Right Ventricular Response to Pulmonary Valve Insertion Surgery: A Passive Anisotropic FSI Model with Fiber Orientation

Right ventricular (RV) dysfunction is a common cause of heart failure inpatients with congenital heart defects and often leads to impaired functional capacity and premature death. The current surgical approach, which includes pulmonary valve replacement/insertion (PVR), has yielded mixed results. MRI-based patient- specific RV/LV/Patch combination models which included fluid-structure interactions (FSI), anisotropic material properties and two-layer construction with fiber orientations were introduced to test the hypothesis that a PVR surgical design with a smaller patch and more aggressive scar tissue trimming would lead to improved RV cardiac function recovery. Results from our models validated by pre-operation data indicated that the small patch design had 10% improvement in RV function as measured by RV ejection fraction, compared to the conventional patch. Maximum Stress-P₁ value from the anisotropic model was 149.6% higher than that from the isotropic model. Computational RV volume predictions agreed well with CMR-measured volume data (error < 3%).