2022/02/11 by Mansoor A. Haider, Katherine J. Pearce, Haider, Mansoor A. +7
Biochemistry, Genetics and Molecular Biology · Engineering · Medicine · #Connective tissue disorders research #Elasticity and Material Modeling #FOS: Biological sciences #Pulmonary Hypertension Research and Treatments #Tissues and Organs (q-bio.TO)
paper · pdf · doi:10.48550/arxiv.2202.12711
openalex publication_date 2022/02/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Pulmonary hypertension is a cardiovascular disorder manifested by elevated arterial blood pressure together with vessel wall stiffening and thickening due to alterations in collagen, elastin and smooth muscle cells. Hypoxia-induced (type 3) pulmonary hypertension can be studied in animals exposed to a low oxygen environment for prolonged time periods leading to biomechanical alterations in vessel wall structure. This study formulates and systematically reduces a nonlinear elastic structural wall model for a large pulmonary artery, generating a novel pressure-area relation capturing remodeling in type 3 pulmonary hypertension. The model is calibrated using \em ex vivo measurements of vessel diameter and wall thickness changes, under controlled flow conditions, in left pulmonary arteries isolated from control and hypertensive mice. A two-layer, hyperelastic, anisotropic model incorporating residual stresses is formulated using the Holzapfel-Gasser-Ogden model. Complex relations predicting vessel area and wall thickness with increasing blood pressure are derived and calibrated using the data. Sensitivity analysis, parameter estimation and subset selection are used to systematically reduce the 16-parameter model to one in which a much smaller subset of identifiable parameters is estimated via solution of an inverse problem. Our final reduced model includes a single set of three elastic moduli. Estimated ranges of these parameters demonstrate that nonlinear stiffening is dominated by elastin in the control animals and by collagen in the hypertensive group. The novel pressure-area relation developed in this study has potential impact on one-dimensional fluids network models of vessel wall remodeling in the presence of cardiovascular disease.