Distinguishing endothelial responses to impingement force, wall shear stress, and wall shear stress gradient

2006 ◽  
Vol 39 ◽  
pp. S312
Author(s):  
E. Metaxa ◽  
J. Kolega ◽  
M.P. Szymanski ◽  
Z.J. Wang ◽  
D.D. Swartz ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Stress Gradient ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear

Numerical Investigation and Prediction of Atherogenic Sites in Branching Arteries

1995 ◽  
Vol 117 (3) ◽  
pp. 350-357 ◽  
Author(s):  
M. Lei ◽  
C. Kleinstreuer ◽  
G. A. Truskey
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Blood Vessels ◽  
Vector Fields ◽  
Stress Gradient ◽  
Western World ◽  
Medium Size ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear

Atherosclerosis, a disease of large- and medium-size arteries, is the chief cause of death in the US and most of the western world. It is widely accepted that the focal nature of the disease in arterial bends, junctions, and bifurcations is directly related to locally abnormal hemodynamics, often labeled “disturbed flows.” Employing the aorto-celiac junction of rabbits as a representative atherosclerotic model and considering other branching blood vessels with their distinctive input wave forms, it is suggested that the local wall shear stress gradient (WSSG) is the single best indicator of nonuniform flow fields leading to atherogenesis. Alternative predictors of susceptible sites are briefly evaluated. The results discussed include transient velocity vector fields, wall shear stress gradient distributions, and a new dimensionless parameter for the prediction of the probable sites of stenotic developments in branching blood vessels. Some of the possible underlying biological aspects of atherogenesis due to locally significant |WSSG|-magnitudes are briefly discussed.

scholarly journals Modulating wall shear stress gradient via equilateral triangular channel for in situ cellular adhesion assay

2016 ◽  
Vol 10 (5) ◽  
pp. 054119 ◽  
Author(s):  
Hyung Woo Kim ◽  
Seonjin Han ◽  
Wonkyoung Kim ◽  
Jiwon Lim ◽  
Dong Sung Kim
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Stress Gradient ◽  
Cellular Adhesion ◽  
Adhesion Assay ◽  
Triangular Channel ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear

scholarly journals Hemodynamics of Cerebral Aneurysm Initiation: The Role of Wall Shear Stress and Spatial Wall Shear Stress Gradient

2011 ◽  
Vol 32 (3) ◽  
pp. 587-594 ◽  
Author(s):  
Z. Kulcsár ◽  
Á. Ugron ◽  
M. Marosfői ◽  
Z. Berentei ◽  
G. Paál ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Cerebral Aneurysm ◽  
Stress Gradient ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear

scholarly journals Pulsatile Wall Shear Stress Gradient and Aortoseptal Angle: Implications for Subaortic Stenosis † 147

1997 ◽  
Vol 41 ◽  
pp. 27-27
Author(s):  
Michael D. VanAuker ◽  
Theresa A. Tacy ◽  
Gunnlaugur Sigfusson ◽  
Pedro J. Del Nido ◽  
Edward G. Cape
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Stress Gradient ◽  
Subaortic Stenosis ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear

Wall shear stress gradient topography in the normal left coronary arterial tree: possible implications for atherogenesis

2004 ◽  
Vol 20 (5) ◽  
pp. 587-596 ◽  
Author(s):  
Thomas M. Farmakis ◽  
Johannes V. Soulis ◽  
George D. Giannoglou ◽  
George J. Zioupos ◽  
George E. Louridas
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Stress Gradient ◽  
Arterial Tree ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear

WALL SHEAR STRESS GRADIENT ANALYSIS WITHIN AN IDEALIZED STENOSIS USING NON-NEWTONIAN FLOW

Neurosurgery ◽  
2007 ◽  
Vol 61 (4) ◽  
pp. 853-864 ◽  
Author(s):  
Clemens M. Schirmer ◽  
Adel M. Malek
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Fluid Dynamic ◽  
Stress Gradient ◽  
Focal Region ◽  
Symptomatic Carotid ◽  
Wall Shear Stress Gradient ◽  
Shear Stress Gradient ◽  
Wall Shear ◽  
Near Wall

Abstract OBJECTIVE The endothelium is functionally regulated by the magnitude and spatiotemporal gradients of wall shear stress (WSS). Although flow separation and reversal occur beyond high-grade stenoses, little is known of the WSS pattern within clinically relevant mild to moderate stenoses. METHODS An axisymmetric geometry with 25, 50, and 75% stenosis criteria (quantified in accordance with the North American Symptomatic Carotid Endarterectomy Trial) was used to generate a high-resolution, hybrid, tetrahedral-hexahedral computational mesh with boundary-layer enrichment to improve near-wall shear stress gradient (WSSG) computation. Time-dependent computational fluid dynamic analysis was performed using a non-Newtonian Carreau-Yasuda model of blood to yield the shear-dependent viscosity. RESULTS Transition to secondary flow patterns was demonstrated in stenoses of 25, 50, and 75%. A focal region with near-wall flow reversal and retrograde WSS was identified within the stenosis itself and was found to migrate cyclically during the cardiac pulse. A zone of zero WSS and divergent WSSG that shifts in toward the throat with increasing stenotic severity was identified. Focal zones of high WSSG with converging and/or diverging direction were uncovered within the stenosis itself, as were expected changes in the distal poststenotic region. These zones of divergent WSSG shift over a substantial length of the stenosis during the course of the cardiac cycle. CONCLUSION Luminal WSS demonstrates dynamic direction reversal and high spatial gradients within the distal stenosis throat of even clinically moderate lesions. These findings shed light on the complex vessel wall hemodynamics within clinical stenoses and reveal a mechanical microenvironment that is conducive to perpetual endothelial functional dysregulation and stenosis progression.

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