Computational Fluid Dynamics Study of Bifurcation Aneurysms Treated with Pipeline Embolization Device: Side Branch Diameter Study.

Abraham Yik-Sau Tang,Kwok-Wing Chow,Gilberto Ka-Kit Leung,Anderson Chun-On Tsang,Alfred Cheuk-Hang Yu,Eric Tian-Yang Liu,Wai-Choi Chung,Jie-Qiong Qu,Kar-Ming Leung

doi:10.1007/s40846-015-0046-3

Abraham Yik-Sau Tang, Kwok-Wing Chow + Show 7 more

Open Access

https://doi.org/10.1007/s40846-015-0046-3

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Abstract

An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.

Highlights

An intracranial aneurysm is a severe cerebrovascular disorder where a portion of the artery wall becomes weakened and dilated
This study focuses on a case with a high aspect ratio, which may be associated with a higher risk of rupture [21]
Idealized Y-shaped models with various side branch diameters were utilized to study the hemodynamics of aneurysms near arterial bifurcations, both before and after flow diverter deployment

Summary

Introduction

An intracranial aneurysm is a severe cerebrovascular disorder where a portion of the artery wall becomes weakened and dilated. It commonly occurs near arterial bifurcations in the Circle of Willis [1, 2]. A popular endovascular treatment for intracranial aneurysms is coil embolization [4]. The underlying principle of this stent deployment mechanism is to divert blood flow from the aneurysm by covering the orifice. This action can disrupt the pulsatile blood flow within an aneurysm sac to the point of stagnation and obliteration, promoting the formation of thrombus.

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