Branch Flow Effects in the Human Right Coronary Artery Trunk

2000 ◽  
Author(s):  
Jerry G. Myers ◽  
M. Ojha ◽  
K. Wayne Johnston ◽  
C. Ross Ethier

Abstract Formation of atherosclerotic plaque in the human right coronary artery (RCA) has, in part, been linked to local hemodynamic factors (Ojha et al., 2000). Thus, there is considerable motivation to accurately characterize hemodynamic patterns in the RCA. Patient-specific geometric characteristics, such as curvature and arterial calibre, have been shown to significantly affect velocity and wall shear stress (WSS) patterns within the RCA trunk (Myers et al., 2000). However it is unclear how flow into arterial branches influences these hemodynamic patterns. In investigating this factor, we computed velocity and WSS distributions in a realistic model of a human right coronary artery (RCA) that included four branches.

2004 ◽  
Vol 24 (12) ◽  
pp. 2408-2413 ◽  
Author(s):  
Anil K. Joshi ◽  
Richard L. Leask ◽  
Jerry G. Myers ◽  
Matadial Ojha ◽  
Jagdish Butany ◽  
...  

Author(s):  
Nanfeng Sun ◽  
Ryo Torii ◽  
Nigel B. Wood ◽  
Andrew Wright ◽  
Alun D. Hughes ◽  
...  

Low wall shear stress (WSS) is commonly implicated in endothelial dysfunction and atherogenesis. The accumulation of macromolecules is also considered as an important factor contributing to the development of atherosclerosis. In the present study a fluid-wall model, incorporating shear-dependent endothelial transport properties, was developed and used to study the transport of albumin from blood to and within the wall in a realistic human right coronary artery (RCA). Numerical simulations were performed at both steady and pulsatile flow conditions, and results were compared to evaluate the effect of flow pulsatility.


1999 ◽  
Vol 121 (4) ◽  
pp. 370-375 ◽  
Author(s):  
A. Kirpalani ◽  
H. Park ◽  
J. Butany ◽  
K. W. Johnston ◽  
M. Ojha

Blood flow dynamics in the human right coronary artery have not been adequately quantified despite the clinical significance of coronary atherosclerosis. In this study, a technique was developed to construct a rigid flow model from a cast of a human right coronary artery. A laser photochromic method was used to characterize the velocity and wall shear stress patterns. The flow conditions include steady flow at Reynolds numbers of 500 and 1000 as well as unsteady flow with Womersley parameter and peak Reynolds number of 1.82 and 750, respectively. Characterization of the three-dimensional geometry of the artery revealed that the largest spatial variation in curvature occurred within the almost branch-free proximal region, with the greatest curvature existing along the acute margin of the heart. In the proximal segment, high shear stresses were observed on the outer wall and lower, but not negative, stresses along the inner wall. Low shear stress on the inner wall may be related to the preferential localization of atherosclerosis in the proximal segment of the right coronary artery. However, it is possible that the large difference between the outer and inner wall shear stresses may also be involved.


2021 ◽  
pp. 1-18
Author(s):  
Abdulgaphur Athani ◽  
N.N.N. Ghazali ◽  
Irfan Anjum Badruddin ◽  
Sarfaraz Kamangar ◽  
Ali E. Anqi ◽  
...  

BACKGROUND: The blood flow in the human artery has been a subject of sincere interest due to its prime importance linked with human health. The hemodynamic study has revealed an essential aspect of blood flow that eventually proved to be paramount to make a correct decision to treat patients suffering from cardiac disease. OBJECTIVE: The current study aims to elucidate the two-way fluid-structure interaction (FSI) analysis of the blood flow and the effect of stenosis on hemodynamic parameters. METHODS: A patient-specific 3D model of the left coronary artery was constructed based on computed tomography (CT) images. The blood is assumed to be incompressible, homogenous, and behaves as Non-Newtonian, while the artery is considered as a nonlinear elastic, anisotropic, and incompressible material. Pulsatile flow conditions were applied at the boundary. Two-way coupled FSI modeling approach was used between fluid and solid domain. The hemodynamic parameters such as the pressure, velocity streamline, and wall shear stress were analyzed in the fluid domain and the solid domain deformation. RESULTS: The simulated results reveal that pressure drop exists in the vicinity of stenosis and a recirculation region after the stenosis. It was noted that stenosis leads to high wall stress. The results also demonstrate an overestimation of wall shear stress and velocity in the rigid wall CFD model compared to the FSI model.


2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Dehong Zeng ◽  
Evangelos Boutsianis ◽  
Marc Ammann ◽  
Kevin Boomsma ◽  
Simon Wildermuth ◽  
...  

A computational model incorporating physiological motion and uniform transient wall deformation of a branchless right coronary artery (RCA) was developed to assess the influence of artery compliance on wall shear stress (WSS). Arterial geometry and deformation were derived from modern medical imaging techniques, whereas the blood flow was solved numerically employing a moving-grid approach using a well-validated in-house finite element code. The simulation results indicate that artery compliance affects the WSS in the RCA heterogeneously, with the distal region mostly experiencing these effects. Under physiological inflow conditions, coronary compliance contributed to phase changes in the WSS time history, without affecting the temporal gradient of the local WSS nor the bounds of the WSS magnitude. Compliance does not cause considerable changes to the topology of WSS vector patterns nor to the localization of WSS minima along the RCA. We conclude that compliance is not an important factor affecting local hemodynamics in the proximal region of the RCA while the influence of compliance in the distal region needs to be evaluated in conjunction with the outflow to the myocardium through the major branches of the RCA.


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