Journal of Biomechanics, 16 November 2018, Vol.81, pp.58-67
Congenital pulmonary artery (PA) stenosis is often associated with abnormal PA hemodynamics including increased pressure drop (Δ ) and reduced asymmetric flow ( ), which may result in right ventricular dysfunction. We propose functional diagnostic parameters, (CDP), ( ), and ( ) to characterize pulmonary hemodynamics, and evaluate their efficacy in delineating stenosis severity using experiments. Subject-specific test sections including the main PA (MPA) bifurcating into left and right PAs (LPA, RPA) with a discrete LPA stenosis were manufactured from cross-sectional imaging and 3D printing. Three clinically-relevant stenosis severities, 90% area stenosis (AS), 80% AS, and 70% AS, were evaluated at different cardiac outputs (COs). A benchtop flow loop simulating pulmonary hemodynamics was used to measure and Δ within the test sections. The experimental Δ - characteristics along with clinical data were used to obtain pathophysiologic conditions and compute the diagnostic parameters. The pathophysiologic decreased as the stenosis severity increased at a fixed CO. CDP , (absolute), and (absolute) increased with an increase in LPA stenosis severity at a fixed CO. Importantly, CDP and had reduced variability with CO, and distinct values for each LPA stenosis severity. Under variable CO, a) CDP values were 14.5–21.0 (70% AS), 60.7– 2.2 (80% AS), 261.6 (90% AS), and b) values (in mJ per ) were −501.9 to −1023.8 (70% AS), −1247.6 to −1773.0 (80% AS), −1934.5 (90% AS). Hence, CDP and are expected to assess the true functional severity of PA stenosis.
Pulmonary Artery Stenosis ; Congenital Heart Disease ; In Vitro Experiments ; Functional Diagnostic Parameters ; Subject-Specific ; Medicine ; Engineering ; Anatomy & Physiology
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