Two Diverse Hemodynamic Forces, a Mechanical Stretch and a High Wall Shear Stress, Determine Intracranial Aneurysm Formation

2019 ◽  
Vol 11 (1) ◽  
pp. 80-92 ◽  
Author(s):  
Hirokazu Koseki ◽  
Haruka Miyata ◽  
Satoshi Shimo ◽  
Nobuhiko Ohno ◽  
Kazuma Mifune ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Intracranial Aneurysm ◽  
Mechanical Stretch ◽  
High Wall Shear Stress ◽  
Hemodynamic Forces ◽  
Aneurysm Formation ◽  
Wall Shear

Effects of smoking and hypertension on wall shear stress and oscillatory shear index at the site of intracranial aneurysm formation

2010 ◽  
Vol 112 (4) ◽  
pp. 306-313 ◽  
Author(s):  
Pankaj K. Singh ◽  
Alberto Marzo ◽  
Bethany Howard ◽  
Daniel A. Rufenacht ◽  
Philippe Bijlenga ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Intracranial Aneurysm ◽  
Oscillatory Shear ◽  
Oscillatory Shear Index ◽  
Aneurysm Formation ◽  
Wall Shear

scholarly journals Wall shear stress gradient is independently associated with middle cerebral artery aneurysm development: a case-control CFD patient-specific study based on 77 patients

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mikołaj Zimny ◽  
Edyta Kawlewska ◽  
Anna Hebda ◽  
Wojciech Wolański ◽  
Piotr Ładziński ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Case Control ◽  
Independent Effect ◽  
Patient Specific ◽  
Aneurysm Formation ◽  
Wall Shear ◽  
Mca Aneurysm

Abstract Background Previously published computational fluid dynamics (CFD) studies regarding intracranial aneurysm (IA) formation present conflicting results. Our study analysed the involvement of the combination of high wall shear stress (WSS) and a positive WSS gradient (WSSG) in IA formation. Methods We designed a case-control study with a selection of 38 patients with an unruptured middle cerebral artery (MCA) aneurysm and 39 non-aneurysmal controls to determine the involvement of WSS, oscillatory shear index (OSI), the WSSG and its absolute value (absWSSG) in aneurysm formation based on patient-specific CFD simulations using velocity profiles obtained from transcranial colour-coded sonography. Results Among the analysed parameters, only the WSSG had significantly higher values compared to the controls (11.05 vs − 14.76 [Pa/mm], P = 0.020). The WSS, absWSSG and OSI values were not significantly different between the analysed groups. Logistic regression analysis identified WSS and WSSG as significant co-predictors for MCA aneurysm formation, but only the WSSG turned out to be a significant independent prognosticator (OR: 1.009; 95% CI: 1.001–1.017; P = 0.025). Significantly more patients (23/38) in the case group had haemodynamic regions of high WSS combined with a positive WSSG near the bifurcation apex, while in the control group, high WSS was usually accompanied by a negative WSSG (14/39). From the analysis of the ROC curve for WSSG, the area under the curve (AUC) was 0.654, with the optimal cut-off value −0.37 Pa/mm. The largest AUC was recognised for combined WSS and WSSG (AUC = 0.671). Our data confirmed that aneurysms tend to form near the bifurcation apices in regions of high WSS values accompanied by positive WSSG. Conclusions The development of IAs is determined by an independent effect of haemodynamic factors. High WSS impacts MCA aneurysm formation, while a positive WSSG mainly promotes this process.

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 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

Role of Hemodynamics in Initiation of Aneurysmal Remodeling

2010 ◽  
Author(s):  
Hui Meng ◽  
Sabareesh K. Natarajan ◽  
Eleni Metaxa ◽  
Markus Tremmel ◽  
Ling Gao ◽  
...  
Keyword(s):  
Risk Factors ◽  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Intracranial Aneurysm ◽  
Hemodynamic Stress ◽  
Key Factor ◽  
Aneurysm Development ◽  
Wall Shear

Hemodynamic insult has long been speculated to be a key factor in intracranial aneurysm (IA) formation,1 but the specifics of hemodynamic insult contributing to this process are not understood. Despite other risk factors, IAs are predominantly found at locations associated with unique hemodynamic stress such as at the apices of arterial bifurcations or outer curves, prominent in high wall shear stress (WSS) and wall shear stress gradients (WSSG).2 Furthermore, it appears that increased flow at these locations is required to trigger the initiation of aneurysmal remodeling.3 We have previously shown that increasing flow in the rabbit basilar artery (BA), secondary to common carotid artery (CCA) ligation, resulted in nascent aneurysm development at the basilar terminus (BT).4 However, it is unclear if certain hemodynamic stress thresholds must be exceeded to trigger aneurysmal remodeling, and whether sustained insult is necessary.

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