Numerical simulations of the blood flow through vertebral arteries

Jóźwik, Krzysztof; Obidowski, D.

doi:10.1016/j.jbiomech.2009.09.026

Cited by 61 publications

(29 citation statements)

References 9 publications

(13 reference statements)

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“…The morphological characteristics of vulnerable plaque have now been well defined in numerous pathological studies [3,16,20,35]. Typically, such plaques have a large extracellular necrotic core and a thin fibrous cap (less than 65 lm) infiltrated by macrophages.…”

Section: Discussionmentioning

confidence: 99%

Effects of severity and location of stenosis on the hemodynamics in human aorta and its branches

Dabagh

Vasava

Jalali

2015

Med Biol Eng Comput

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Pulsatile blood flow is studied in a three-dimensional model of human thoracic aorta at different stages of atherosclerotic lesion growth, taking into account the effect of atherosclerotic plaque location and peripheral symmetry. The model is reconstructed from the computed tomography images. The wall shear stress (WSS), time-averaged WSS, and the oscillatory shear index are applied to determine susceptible sites for the onset of early atherosclerosis. Then, two different degrees of stenosis severity, 50 and 80 %, are introduced to vulnerable areas of the healthy aorta geometry. The overriding issue addressed is that the WSS distribution and magnitude are strongly affected by the atherosclerotic plaque size, its symmetric features, and the location, i.e., the branch it is formed. The present study, for the first time, is capable of providing information on the high shear environment that may exist upon the rupture of plaque surface and any thrombosis due to platelet deposition. The magnitude of WSS and its distribution at the throat of 50 % stenosed aortic arch are in agreement with the previous numerical study (Huang et al. in Exp Fluids 48(3):497-508, 2010). Results show that WSS values exceed 50 Pa at the throat of 80 % stenosed left common carotid and brachiocephalic arteries.

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Section: Discussionmentioning

confidence: 99%

Effects of severity and location of stenosis on the hemodynamics in human aorta and its branches

Dabagh

Vasava

Jalali

2015

Med Biol Eng Comput

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“…For an individual geometric configuration of the vertebrobasilar artery system, there may be also considerable differences in the diameter between the left and the right arteries. All these variations may result in significant blood flow differences within the VAs and the VJ, 16 that, in the diagnostic setting, may unsoundly lead to the hypothesis of arterial disease. Presented results suggest that torsion of the neck associated with head rotation may complicate this situation even further by affecting both geometry and blood flow field in VAs.…”

Section: Discussionmentioning

confidence: 99%

“…The impact of these assumptions in computed hemodynamics has been previously discussed extensively. 16,23,24,32 Meshes of approximate 2.2 9 10 6 size were constructed by ICEM-CFD v12.1 (Ansys Inc.). More details on meshing are provided elsewhere.…”

Section: Computational Simulationsmentioning

confidence: 99%

The Effect of Head Rotation on the Geometry and Hemodynamics of Healthy Vertebral Arteries

et al. 2015

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The geometric and hemodynamic characteristics of the left and right vertebral arteries (LVA, RVA) of six healthy volunteers were investigated for the supine (S) and the prone position (P) a common sleeping posture with head rotation. MRI images were used to reconstruct the subject specific three-dimensional solid models of the LVA and RVA from the level of the carotid bifurcation to the vertebrobasilar junction (VJ). Geometric parameters such as cross sectional area ratio, curvature, tortuosity and branch angle were estimated. MR-PCA was used to obtain the blood flow waveforms for the two positions and computational fluid dynamics (CFD) were used to assess the flow field in terms of wall shear stress (WSS) relative residence times (RRT) and localized normalized helicity (LNH). Significant geometric changes but moderate flow changes were observed for both vertebral arteries with head rotation. The CFD results at the VJ show that head rotation causes changes in the WSS distribution, RRT and LNH. Further studies are warranted to assess the clinical significance of the results in terms of atherosclerosis development at the VJ and how the observed geometric changes may affect blood flow to the brain in healthy subjects and vertebral artery stenosis patients, and in terms of increased rapture susceptibility in vertebrobasilar aneurysm patients.

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“…The CFD simulation was first run with steady-state flow analysis and then with transient flow analysis based on the results of the steady-state analysis as the initial estimate 25,26 . For the steady-state analysis, values of the following parameters were set at the inlet and outlet:…”

Section: Numerical Methodologymentioning

confidence: 99%

“…Under these conditions of stenosis severity, the probability of shear layer instabilities occurring at a relatively low Reynolds number is high because of the possible disturbances in the cardiac pulse and irregularities in the plaque anatomy under hyperemic flow conditions 23,24 . A shear stress transport turbulence model of the k- model family was adopted for flow modelling because of its accuracy and robustness in overcoming the near-wall treatment errors for low Reynolds number turbulence flow 25 . The throat diameters for 70%, 80% and 90% AS were 1.64, 1.34 and 0.94 mm respectively.…”

Section: Meshing and Boundary Conditionsmentioning

confidence: 99%

A Parametric Study of the Effect of Arterial Wall Curvature on Non-Invasive Assessment of Stenosis Severity:Computational Fluid Dynamics Study

et al. 2016

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Numerical simulations of the blood flow through vertebral arteries

Cited by 61 publications

References 9 publications

Effects of severity and location of stenosis on the hemodynamics in human aorta and its branches

Effects of severity and location of stenosis on the hemodynamics in human aorta and its branches

The Effect of Head Rotation on the Geometry and Hemodynamics of Healthy Vertebral Arteries

A Parametric Study of the Effect of Arterial Wall Curvature on Non-Invasive Assessment of Stenosis Severity:Computational Fluid Dynamics Study

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