Does the inflow velocity profile influence physiologically relevant flow patterns in computational hemodynamic models of left anterior descending coronary artery?. (August 2020)

• Record Type: Journal Article
• Authors: Lodi Rizzini, Maurizio; Gallo, Diego; De Nisco, Giuseppe; D'Ascenzo, Fabrizio; Chiastra, Claudio; Bocchino, Pier Paolo; Piroli, Francesco; De Ferrari, Gaetano Maria; Morbiducci, Umberto
• Is Part Of: Medical engineering & physics. Volume 82(2020)
• Page Start: 58
• Page End: 69
• Publication Date: 2020-08
• Subjects: Cardiovascular models uncertainty -- Boundary conditions -- Computational fluid dynamics -- Coronary arteries -- Helical flow -- Wall shear stress; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2020.07.001
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: Computational hemodynamics in coronary arteries is affected by uncertainties. The velocity profile applied as inflow boundary condition is a source of uncertainty. A framework is developed to generate analytical, realistic 3D velocity profiles. The velocity profile impacts local hemodynamics in the proximal segment only. The velocity profile impact length is generally shorter than the theoretical entrance length. Abstract: Patient-specific computational fluid dynamics is a powerful tool for investigating the hemodynamic risk in coronary arteries. Proper setting of flow boundary conditions in computational hemodynamic models of coronary arteries is one of the sources of uncertainty weakening the findings of in silico experiments, in consequence of the challenging task of obtaining in vivo 3D flow measurements within the clinical framework. Accordingly, in this study we evaluated the influence of assumptions on inflow velocity profile shape on coronary artery hemodynamics. To do that, (1) ten left anterior descending coronary artery (LAD) geometries were reconstructed from clinical angiography, and (2) eleven velocity profiles with realistic 3D features such as eccentricity and differently shaped (single- and double-vortex) secondary flows were generated analytically and imposed as inflow boundary conditions. Wall shear stress and helicity-based descriptors obtained prescribing the commonly used parabolic velocity profile were compared with those obtained with the other velocity profiles. Our findings indicated that the imposition of idealized velocity profiles as inflow boundary condition is acceptable as long the results of the proximal vessel segment are not considered, in LAD coronary arteries. As a pragmatic rule of thumb, a conservative estimation of the length of influence of the shape of the inflow velocity profile on LAD local hemodynamics can be given by the theoretical entrance length for cylindrical conduits in laminar flow conditions.