Critical Influence of Framing Coil Orientation on Intra-Aneurysmal and Neck Region Hemodynamics in a Sidewall Aneurysm Model

Neurosurgery ◽  
2010 ◽  
Vol 67 (6) ◽  
pp. 1692-1702 ◽  
Author(s):  
Clemens M Schirmer ◽  
Adel M Malek
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Dynamic Analysis ◽  
Computational Fluid Dynamic ◽  
Rank Order ◽  
Fluid Dynamic ◽  
Parent Vessel ◽  
Computational Fluid Dynamic Analysis ◽  
Wall Shear

Abstract BACKGROUND: Although coiling of intracranial aneurysms is thought to rely on obstruction of blood flow into the aneurysm and induction of intra-aneurysmal thrombosis, little data exist regarding the effect of coil deployment on hemodynamics. OBJECTIVE: To evaluate the effects of simulated coiling of a model aneurysm on flow and wall shear stress in the dome and neck regions using computational fluid dynamic analysis. METHODS: A spherical sidewall aneurysm on a curved parent vessel underwent simulated embolization with 1 or more computer-designed helical coils. The coils' axes had parallel, orthogonal, or transverse orientation with respect to blood flow. Pulsatile laminar flow computational fluid dynamic analysis was performed on high-resolution conformal meshes of the aneurysm-coil complex using realistic non-Newtonian blood viscosity. RESULTS: Intra-aneurysmal flow and energy flux into the dome were significantly reduced by coil insertion, with little effect on pressure distribution. Coiling increased viscosity in the distal dome with progressive spread toward the neck with greater coil packing. Coiling also decreased wall shear stress and its gradient both in the inflow zone and the downstream parent vessel. These alterations were dependent on coil orientation, with effectiveness rank order of parallel > transverse > orthogonal. CONCLUSION: We successfully modeled the hemodynamic effects of aneurysm coil embolization and uncovered a framing coil orientation dependence of dome and parent vessel hemodynamics. In addition to suggesting a pathophysiological link among coil configuration, protection from rupture, and aneurysm regrowth, these results pave the way for the analysis of aneurysm-coil complex interactions on a patient lesion-specific basis.

Y-Stent Coiling of Basilar Bifurcation Aneurysms Induces a Dynamic Angular Vascular Remodeling With Alteration of the Apical Wall Shear Stress Pattern

Neurosurgery ◽  
2012 ◽  
Vol 72 (4) ◽  
pp. 617-629 ◽  
Author(s):  
Bulang Gao ◽  
Merih I. Baharoglu ◽  
Alex D. Cohen ◽  
Adel M. Malek
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Dynamic Analysis ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Cerebral Arteries ◽  
Patient Specific ◽  
Computational Fluid Dynamic Analysis ◽  
Hemodynamic Forces ◽  
Wall Shear

Abstract BACKGROUND: Although wide-necked basilar bifurcation aneurysms are treated with Y-stent coiling, the effect of this intervention on vessel configuration and hemodynamics is unknown. OBJECTIVE: To investigate the immediate and delayed effects of Y-stenting using self-expanding microstents on basilar bifurcation architecture and hemodynamics. METHODS: Fifteen patients underwent basilar Y-stent coiling and imaging with rotational angiography. Vascular angles were measured between proximal P1 segments of the posterior cerebral arteries (α) and between the basilar artery and each P1 segment (β1,2) in the anteroposterior and γ1,2 sagittal planes. Patient-specific computational fluid dynamic analysis was used to estimate wall shear stress (WSS) changes with treatment. RESULTS: In the anteroposterior plane, Y-stenting significantly decreased angle α and increased β angles immediately after stent coiling (P < .05 and P < .01, respectively) in a continued dynamic remodeling that progressed further in later months; sagittal γ angles also decreased (P < .0001). This novel stent-induced geometric progressive remodeling resulted in effective straightening and narrowing of the basilar bifurcation angle α (150.0 degrees vs 113 degrees, P < .0001) with significant correlation (r = 0.39, P < .05) between pretreatment proximal P1 angles and maximal angular change. Computational fluid dynamic analysis showed the angular remodeling led to significant narrowing of the WSS interpeak at the apex, redirecting high WSS away from the neck transition zone with native vessel toward the inert coil mass. CONCLUSION: Y-configuration stent coiling induced immediate and, more significantly, a previously undefined delayed cerebrovascular remodeling. This progressive stent-induced angular remodeling alters perianeurysmal hemodynamics, independent of the flow-diverting properties of stent struts, thus shifting the balance of hemodynamic forces affecting aneurysm development and evolution.

Computational fluid dynamic measures of wall shear stress are related to coronary lesion characteristics

Heart ◽  
2016 ◽  
Vol 102 (20) ◽  
pp. 1655-1661 ◽  
Author(s):  
Jun-Bean Park ◽  
Gilwoo Choi ◽  
Eun Ju Chun ◽  
Hyun Jin Kim ◽  
Jonghanne Park ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Coronary Lesion ◽  
Wall Shear ◽  
Dynamic Measures

Computational fluid dynamic-derived wall shear stress of non-significant left main bifurcation disease may predict acute vessel thrombosis at 3-year follow-up

2019 ◽  
Vol 35 (3) ◽  
pp. 297-306 ◽  
Author(s):  
Marco Zuin ◽  
Gianluca Rigatelli ◽  
Dobrin Vassilev ◽  
Federico Ronco ◽  
Alberto Rigatelli ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Left Main ◽  
Wall Shear ◽  
Vessel Thrombosis

Effects of blood flow characteristics on rupture of cerebral aneurysm: Computational study

2021 ◽  
pp. 2150143
Author(s):  
Xiao-Yong Shen ◽  
M. Barzegar Gerdroodbary ◽  
Amin Poozesh ◽  
Amir Musa Abazari ◽  
S. Misagh Imani
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
High Risk ◽  
Wall Shear Stress ◽  
Flow Pattern ◽  
Cerebral Aneurysm ◽  
Computational Study ◽  
Fluid Dynamic ◽  
Aneurysm Wall ◽  
Wall Shear

In recent decades, cardiovascular disease and stroke are recognized as the most important reason for the high death rate. Irregular bloodstream and the circulatory system are the main reason for this issue. In this paper, Computational Fluid dynamic method is employed to study the impacts of the flow pattern inside the cerebral aneurysm for detection of the hemorrhage of the aneurysm. To achieve a reliable outcome, blood flow is considered as a non-Newtonian fluid with a power-law model. In this study, the influence of the blood viscosity and velocity on the pressure distribution and average wall shear stress (AWSS) are comprehensively studied. Moreover, the flow pattern inside the aneurysm is investigated to obtain the high-risk regions for the rupture of the aneurysm. Our results indicate that the wall shear stress (WSS) increases with increasing blood flow velocity. Furthermore, the risk of aneurysm rupture is considerably increased when the AWSS increases more than 0.6. Indeed, the blood flow with high viscosity expands the high-risk region on the wall of the aneurysm. Blood flow indicates that the angle of the incoming bloodstream is substantially effective in the high-risk region on the aneurysm wall. The augmentation of the blood velocity and vortices considerably increases the risk of hemorrhage of the aneurysm.

scholarly journals Computational Fluid Dynamic Simulations of Maternal Circulation: Wall Shear Stress in the Human Placenta and Its Biological Implications

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0147262 ◽  
Author(s):  
E. Lecarpentier ◽  
M. Bhatt ◽  
G. I. Bertin ◽  
B. Deloison ◽  
L. J. Salomon ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Computational Fluid Dynamic ◽  
Human Placenta ◽  
Fluid Dynamic ◽  
Maternal Circulation ◽  
Dynamic Simulations ◽  
Wall Shear

Angular Remodeling in Single Stent-Assisted Coiling Displaces and Attenuates the Flow Impingement Zone at the Neck of Intracranial Bifurcation Aneurysms

Neurosurgery ◽  
2013 ◽  
Vol 72 (5) ◽  
pp. 739-748 ◽  
Author(s):  
Bulang Gao ◽  
Merih I. Baharoglu ◽  
Adel M. Malek
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Bifurcation Angle ◽  
Impingement Zone ◽  
Wall Shear ◽  
And Migration ◽  
The Impact

Abstract BACKGROUND: Self-expanding intracranial stent-assisted coiling of bifurcation aneurysms has recently been shown to straighten target cerebral vessels, a phenomenon with unknown hemodynamic effect. OBJECTIVE: To investigate the impact of angular remodeling in aneurysms treated with single stent-assisted coiling with the use of computational fluid dynamic techniques. METHODS: Fourteen patients (7 women, mean age 55) who underwent stent coiling of 14 wide-necked bifurcation aneurysms were included based on the availability of high-resolution 3-dimensional rotational angiography. Pretreatment data sets underwent virtual aneurysm removal to isolate the effect of stenting. Wall shear stress and pressure profiles obtained from constant flow input computational fluid dynamic analysis were analyzed for apical hemodynamic changes. RESULTS: Stenting increased the bifurcation angle with significant straightening immediately after treatment and at follow-up (107.3° vs 144.9°, P < .001). The increased stented angle at follow-up led to decreased pressure drop at the bifurcation apex (12.2 vs 9.9 Pa, P < .003) and migration of the flow impingement zone (FIZ) toward the contralateral nonstented daughter branch by a mean of 1.48 ± 0.2 mm. Stent-induced angular remodeling decreased FIZ width separating peak apical wall shear stress (3.4 vs 2.5 mm, P < .004). Analysis of FIZ distance measured from the parent vessel centerline showed it to be linearly (r = .58, P < .002) and FIZ width inversely correlated (r = .46, P < .02) to vessel bifurcation angle. CONCLUSION: Stent-induced angular remodeling significantly altered bifurcation apex hemodynamics in a favorable direction by blunting apical pressure and inducing the narrowing and migration of the FIZ, a novel response to intracranial stenting that should be added to intimal hyperplasia and flow diversion.

P 1 Computational fluid dynamic simulations of maternal circulation – Wall shear stress in the human placenta and its biological implications

2017 ◽  
Vol 9 ◽  
pp. 36-37
Author(s):  
Edouard Lecarpentier ◽  
Mrugank Bhatt ◽  
Gwladys Bertin ◽  
Benjamin Deloison ◽  
Laurent Salomon ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Computational Fluid Dynamic ◽  
Human Placenta ◽  
Fluid Dynamic ◽  
Maternal Circulation ◽  
Dynamic Simulations ◽  
Wall Shear
Sign in / Sign up

Export Citation Format

Share Document