An Integrated Lumped Parameter Model and Computational Fluid Dynamics Framework for Predicting Hemodynamic Parameters...

Pediatric pulmonary vein stenosis (PVS) is a progressive vascular disease associated with poor long-term outcomes. A growing body of evidence supports a relationship between the mechanisms of PVS pathogenesis and atypical hemodynamic conditions within the pulmonary veins; however, there is still a limited understanding of how this hemodynamic environment changes in different presentations of PVS. We propose a novel framework for the study of hemodynamics within the pulmonary veins that integrates computational fluid dynamics (CFD) models with a lumped parameter model (LPM) of the surrounding cardiovascular system. Model coupling is accomplished through surrogate model representation of the CFD domain, allowing for computationally efficient LPM parameter optimization for LPM calibration to specified target values of pressure and volume. The framework was employed to simulate five patient-representative scenarios including varying degrees of stenosis severity, varying number of stenotic veins, and the presence of left-to-right shunt physiology. The distribution of time-averaged wall shear stress (TAWSS) within the proximal pulmonary veins was assessed, as well as predicted flows, pressures, and volumes within the pulmonary arteries, veins, and ventricles.