The role of wall shear stress in the parent artery as an independent variable in the formation status of anterior communicating artery aneurysms

2018 ◽  
Vol 29 (2) ◽  
pp. 689-698 ◽  
Author(s):  
Xin Zhang ◽  
Zhi-Qiang Yao ◽  
Tamrakar Karuna ◽  
Xu-Ying He ◽  
Xue-Min Wang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Anterior Communicating Artery ◽  
Parent Artery ◽  
Anterior Communicating Artery Aneurysms ◽  
Independent Variable ◽  
Wall Shear

scholarly journals Hemodynamics Modeling and Simulation of Anterior Communicating Artery Aneurysms

2014 ◽  
Vol 6 ◽  
pp. 908357 ◽  
Author(s):  
Jianjun Li ◽  
Shengzhang Wang ◽  
Gang Lu ◽  
Xiaolong Zhang
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Cerebral Aneurysms ◽  
Artery Aneurysm ◽  
Oscillatory Shear ◽  
Anterior Communicating Artery ◽  
Rupture Risk ◽  
Oscillatory Shear Index ◽  
Anterior Communicating Artery Aneurysms ◽  
Wall Shear

It is a general agreement that hemodynamics plays very important role in the initiation, growth, and rupture of cerebral aneurysms and hemodynamics in the anterior communicating artery aneurysms is considered the most complex in all cerebral aneurysms and it is difficult to find some reasonable relationship between the hemodynamics parameters and the rupture risk. In this paper, the 3D geometries of four anterior communicating artery aneurysms were generated from the CTA data and the computational models with bilateral feeding arteries for the four aneurysms were constructed. The blood flow was simulated by computational fluid dynamics software and the hemodynamics parameters such as velocity, wall shear stress, and oscillatory shear index were calculated. The following results were observed: one of the four models only needs the left feeding artery; the max normalized wall shear stress locates at the aneurysmal neck of the largest aneurysm; the max oscillatory shear index locates at the aneurysmal sac of the largest aneurysm. The conclusion was drawn that the anterior communicating artery aneurysm has higher rupture risk from the hemodynamics viewpoint if the max wall shear stress locates at the neck and the max oscillatory shear index locates at the dome.

scholarly journals Piezo1 mediates angiogenesis through activation of MT1-MMP signaling

2019 ◽  
Vol 316 (1) ◽  
pp. C92-C103 ◽  
Author(s):  
Hojin Kang ◽  
Zhigang Hong ◽  
Ming Zhong ◽  
Jennifer Klomp ◽  
Kayla J. Bayless ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Matrix Metalloproteinase ◽  
Matrix Metalloproteinase 2 ◽  
Sprouting Angiogenesis ◽  
Sphingosine 1 Phosphate ◽  
Wall Shear ◽  
Membrane Type

Angiogenesis is initiated in response to a variety of external cues, including mechanical and biochemical stimuli; however, the underlying signaling mechanisms remain unclear. Here, we investigated the proangiogenic role of the endothelial mechanosensor Piezo1. Genetic deletion and pharmacological inhibition of Piezo1 reduced endothelial sprouting and lumen formation induced by wall shear stress and proangiogenic mediator sphingosine 1-phosphate, whereas Piezo1 activation by selective Piezo1 activator Yoda1 enhanced sprouting angiogenesis. Similarly to wall shear stress, sphingosine 1-phosphate functioned by activating the Ca2+ gating function of Piezo1, which in turn signaled the activation of the matrix metalloproteinase-2 and membrane type 1 matrix metalloproteinase during sprouting angiogenesis. Studies in mice in which Piezo1 was conditionally deleted in endothelial cells demonstrated the requisite role of sphingosine 1-phosphate-dependent activation of Piezo1 in mediating angiogenesis in vivo. These results taken together suggest that both mechanical and biochemical stimuli trigger Piezo1-mediated Ca2+ influx and thereby activate matrix metalloproteinase-2 and membrane type 1 matrix metalloproteinase and synergistically facilitate sprouting angiogenesis.

scholarly journals The Role of Wall Shear Stress in the Assessment of Right Ventricle Hydraulic Workload

2015 ◽  
Vol 5 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Vitaly Kheyfets ◽  
Mirunalini Thirugnanasambandam ◽  
Lourdes Rios ◽  
Daniel Evans ◽  
Triston Smith ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Right Ventricle ◽  
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.

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

Morphological Effect on Wall Shear Stress in Intracranial Aneurysms

2017 ◽  
Vol 79 (02) ◽  
pp. 108-115 ◽  
Author(s):  
Tian-Lun Qiu ◽  
Guo-Liang Jin ◽  
Hai-Tao Lu ◽  
Wu-Qiao Bao
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Intracranial Aneurysms ◽  
Multivariable Analysis ◽  
Morphological Characteristics ◽  
Parent Artery ◽  
Parent Vessel ◽  
Morphological Effect ◽  
Neck Width ◽  
Wall Shear

Background and Study Aims Both high and low wall shear stress (WSS) play important roles in the development and rupture of intracranial aneurysms (IAs). This study aimed to determine the morphological factors that affect WSS in the IA and the parent artery. Material and Methods We studied a total of 66 IAs with three-dimensional imaging. Computational fluid dynamics (CFD) models were constructed and used to characterize the hemodynamics quantitatively. Aneurysms were grouped according to the mean neck width. The associations among hemodynamics and morphology were analyzed. Results Aspect ratio was correlated to lowest WSS (r = − 0.576), aneurysm-to-parent vessel (A-P) WSS ratio (r = − 0.500), and lowest-parent vessel (L-P) WSS ratio (r = − 0.575). Height-to-width ratio and height were correlated to WSS. Mean aneurysm WSS (p = 0.023), lowest WSS (p < 0.0001), highest-to-lowest WSS ratio (p = 0.004), L-P WSS ratio (p < 0.0001), highest-parent vessel (H-P) WSS ratio (p = 0.008), A-P WSS ratio (p < 0.001), and height (p < 0.001) were different between the two groups of aneurysms that were divided by the relationship between the diameters of the aneurysms and the necks. Multivariable analysis showed that the lowest WSS (p = 0.028) and A-P WSS ratio (p = 0.001) were independently associated with neck width. Conclusion Morphological characteristics are associated with IA and parent vessel WSS. Aneurysms with different neck widths have different hemodynamics. These results could help in understanding the progression of IA and in building predictive models for IA rupture.

Wall Shear Stress in Development Process of Aneurysm Around Anterior Communicating Artery

2004 ◽  
Author(s):  
Kenichi Umezawa ◽  
Akihiro Torisu ◽  
Susumu Kudo ◽  
Ryuhei Yamaguchi
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Steady Flow ◽  
Flow Rate ◽  
Development Process ◽  
Anterior Cerebral Artery ◽  
High Flow ◽  
Anterior Communicating Artery ◽  
Wall Shear ◽  
Small Aneurysm

In the present paper, the distribution of the wall shear stress around the apex of the anterior communicating artery (ACoA) in the development process of aneurysm has been studied in laminar steady flow. The anterior communicating artery composing the circle of Willis is one of the predilection sites where the cerebral aneurysm occurs frequently. Once the small aneurysm initiates around the apex in one anterior cerebral artery (ACA) with high flow rate, the distribution of the wall shear stress abruptly changes around the initial aneurysm. With the development of the aneurysm, the wall shear stress distinctly changes along the concaved surface of the aneurysm. The distribution of the wall shear stress in the development process of the aneurysm is physiologically discussed from the viewpoint of hemodynamics.

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