Oscillation of Wall Shear Stress in Growing Intracranial Aneurysms: A Case Study

2011 ◽  
Author(s):  
Shin-ichiro Sugiyama ◽  
Akira Takahashi ◽  
Teiji Tominaga
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Intracranial Aneurysms ◽  
High Wall Shear Stress ◽  
General Consensus ◽  
Aneurysm Growth ◽  
Wall Shear

Hemodynamics is thought to influence the initiation, growth, and rupture of intracranial aneurysms. While there seems to be general consensus that high wall shear stress results in the initiation of intracranial aneurysms, the hemodynamic conditions that drive the development of aneurysms after initiation are still not completely elucidated. High wall shear stress has been postulated to account for aneurismal progression from the distal neck where flow impinges, whereas low wall shear stress has been associated with aneurysm growth in the dome.1

High Wall Shear Stress and Positive Wall Shear Stress Gradient Trigger the Initiation of Intracranial Aneurysms

2009 ◽  
Author(s):  
Eleni Metaxa ◽  
Markus Tremmel ◽  
Jianping Xiang ◽  
John Kolega ◽  
Max Mandelbaum ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Intracranial Aneurysms ◽  
Potential Role ◽  
Stress Gradient ◽  
Local Flow ◽  
High Wall Shear Stress ◽  
Wall Shear Stress Gradient ◽  
Wall Shear

While the pathogenesis of an intracranial aneurysm (IA) is poorly understood, it has been generally postulated to be related to hemodynamic insult. IAs are predominantly located at apices of arterial bifurcations or outer curves on or near the Circle of Willis, suggesting a potential role of the specific hemodynamics at such locations characterized by high wall shear stress (WSS). Clinically, new IA formation has been observed following local flow increase.

scholarly journals Hemodynamic Analysis on the Anastomosis Angle in Arteriovenous Graft Using Multiphase Blood Model

2021 ◽  
Vol 11 (17) ◽  
pp. 8160
Author(s):  
Ji Tae Kim ◽  
Hyangkyoung Kim ◽  
Hong Sun Ryou
Keyword(s):  
Computed Tomography ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Arteriovenous Graft ◽  
Venous Anastomosis ◽  
Vein Wall ◽  
High Wall Shear Stress ◽  
Anastomosis Site ◽  
Wall Shear ◽  
Tomography Data

Numerical analysis was performed for the effect of the venous anastomosis angle in a forearm arteriovenous graft for hemodialysis using a multiphase blood model. The geometry of the blood vessel was generated based on the patient-computed tomography data. The anastomosis angles were set at 15°, 30°, and 45°. The hematocrit was set at 34%, 45%, and 58%. The larger anastomosis angle, high wall shear stress area >11 Pa, increases to the side of the vein wall away from the anastomosis site. Further, the relatively low wall shear stress area, <3 Pa, occurs near the anastomosis site in larger anastomosis angles. Therefore, the effect of high wall shear stress has advantages in the vicinity of the anastomosis, as the anastomosis angle is larger, but disadvantages as the distance from the anastomosis increases. Moreover, patients with low hematocrit are advantageous for WSS area.

scholarly journals Aneurysm Growth Occurs at Region of Low Wall Shear Stress

Stroke ◽  
2008 ◽  
Vol 39 (11) ◽  
pp. 2997-3002 ◽  
Author(s):  
Loic Boussel ◽  
Vitaliy Rayz ◽  
Charles McCulloch ◽  
Alastair Martin ◽  
Gabriel Acevedo-Bolton ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Aneurysm Growth ◽  
Wall Shear

scholarly journals TCT CONNECT-401 Stent Underexpansion Is Associated With High Wall Shear Stress: A Biomechanical Analysis of the Shear Stent Study

2020 ◽  
Vol 76 (17) ◽  
pp. B172
Author(s):  
Sonali Kumar ◽  
David Molony ◽  
Kaylyn Crawford ◽  
Ryan Dunn ◽  
Elizabeth Thompson ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Biomechanical Analysis ◽  
High Wall Shear Stress ◽  
Wall Shear

scholarly journals Targeting functionalized nanoparticles to activated endothelial cells under high wall shear stress

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Hila Zukerman ◽  
Maria Khoury ◽  
Yosi Shammay ◽  
Josué Sznitman ◽  
Noah Lotan ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Functionalized Nanoparticles ◽  
High Wall Shear Stress ◽  
Wall Shear

Quantification of Discretization Error in Wall Shear Stress Calculations for Aneurismal Flows Using CFD

2008 ◽  
Author(s):  
Francisco A. Pino-Romainville ◽  
Jagannath R. Nanduri ◽  
Ismail B. Celik ◽  
Ansaar T. Rai
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Discretization Error ◽  
Computational Hemodynamics ◽  
Aneurysm Growth ◽  
Local Grid ◽  
Aneurysm Volume ◽  
Wall Shear ◽  
Asme Journal ◽  
Flow Variables

Many recent studies suggest that hemodynamic factors such as wall shear stress (WSS) and pressure contribute to the genesis and growth of intracranial aneurysms. Recently there have been a number of computational hemodynamics studies that calculate the values of wall shear stress in arterial and aneurismal flows. However there is a lack of comprehensive error analysis in many of the computational hemodynamics studies. This is perhaps the reason for speculative and ambiguous conclusions drawn by various studies as to the nature of wall shear stress responsible for aneurysm growth. In the current study, geometry involving an actual aneurysm is built from angiogram images. Another geometry consisting of the primary artery where the aneurysm formed is also built by removing the aneurysm volume. The two geometries are meshed using three different grid densities. Second order schemes are used to simulate the pulsatile hemodynamics through each of the geometries. Various representative planes along the geometries are considered and the major flow variables and WSS are plotted as a function of grid densities. The procedure for estimation of discretization error, suggested by ASME Journal of Fluids Engineering, is applied at various representative locations along the aneurysm and arterial geometry. The results suggest high dependence of calculated WSS on local grid density. The contours of WSS in the arterial geometry suggest that high WSS does not necessarily occur at the location where the aneurysm originated. Possible remedies are suggested so that this uncertainty could be eliminated from future studies.

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