Estimating pulmonary arterial remodeling via an animal-specific computational model of pulmonary artery stenosis

Area of Science:

• Cardiovascular Physiology
• Pediatric Cardiology
• Biomedical Engineering

Background:

• Pulmonary artery stenosis (PAS) is common in children with congenital heart disease, impacting growth and pulmonary vasculature development.
• Variability in PAS characteristics leads to diverse vascular remodeling, posing challenges for in vivo measurement.
• Computational fluid dynamics (CFD) offers a method to investigate hemodynamic alterations and mechanics in PAS.

Purpose of the Study:

• To simulate pulmonary artery hemodynamics in individual animals with left pulmonary artery (LPA) stenosis using a 1D fluid dynamics model.
• To estimate pulmonary vasculature remodeling, which is difficult to measure directly in vivo.
• To understand pulmonary arterial adaptation in response to LPA stenosis.

Main Methods:

• A one-dimensional (1D) fluid dynamics model was employed to simulate hemodynamics in the pulmonary arteries.
• Animal-specific imaging defined the geometry of large pulmonary arteries; distal vasculature was modeled using a three-element Windkessel model.
• Model-fitted parameters were used to estimate pulmonary vasculature remodeling, including stiffness and compliance.

Main Results:

• The left pulmonary artery (LPA) stenosis group showed significantly higher large artery stiffness on the left side compared to the sham group.
• The LPA stenosis group exhibited a larger distribution of total distal vascular resistance on the left side.
• Peripheral compliance on the right side was significantly greater in the LPA stenosis group than in the sham group.

Conclusions:

• The CFD model provides insights into pulmonary arterial adaptation to LPA stenosis.
• Underperfused distal vasculature in LPA stenosis likely experiences moderate radius decrease with minimal stiffness change.
• The developed model shows potential for noninvasively estimating pulmonary vasculature remodeling.