检索结果-南通市图书馆

A joint computational-experimental study of intracranial aneurysms:Importance of the aspect ratio

Journal of Hydrodynamics 2016年第3期28卷 462-472页

作者： Simon Sui-Man LAI abraham yik-sau tang Anderson Chun-On TSANG Gilberto Ka-Kit LEUNG Alfred Cheuk-Hang YU Kwok Wing CHOW Department of Electrical and Electronic Engineering University of Hong Kong Hong Kong China Department of Mechanical Engineering University of Hong Kong Hong Kong China Department of Surgery Li Ka Shing Faculty of Medicine University of Hong Kong Hong Kong China Department of Electrical and Computer Engineering University of Waterloo Ontario Canada

Rupture of a cerebral aneurysm （abnormal swelling of blood vessel in the brain） will cause subarachnoid hemorrhage, and will result in an alarming rate of mortality and morbidity. A joint computational-experimental study is conducted to assess the importance of the aspect ratio in the dynamics of blood flow. The aspect ratio is defined here to be the ratio of the height of the aneurysm to the linear dimension of the neck. Idealized models of such aneurysms located near a bifurcation point were investigated. Numerical simulations for hemodynamic properties like shear stress and flow rate were performed. The computational results were verified experimentally with specially fabricated phantoms, blood mimicking fluid and Doppler ultrasound imaging. Excellent agreements were obtained. Two features are highlighted, providing information in the intensely debated link between rupture risk and geometric factors. On increasing the aspect ratios, firstly, a jet impinging on the distal part of the neck can be observed, and secondly, a region of positive shear stress gradient can be found there. Furthermore, computational analyses for four patient-specific models were conducted to correlate with the results of idealized models and to provide further clinical insight.

关键词： intracranial aneurysms aspect ratio Doppler ultrasound

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of the aspect ratio on the endovascular treatment of intracranial aneurysms: A computational investigation

引用

Journal of Biomedical Science and Engineering 2012年第8期5卷 422-431页

作者： abraham yik-sau tang Siu-Kai Lai Kar-Ming Leung Gilberto Ka-Kit Leung Kwok-Wing Chow Department of Mechanical Engineering University of Hong Kong Pokfulam Hong Kong Department of Neurosurgery Kwong Wah Hospital Hong Kong Division of Neurosurgery Department of Surgery Li Ka Shing Faculty of Medicine University of Hong Kong Queen Mary

Intracranial aneurysm, a localized dilation of arterial blood vessels in the Circle of Willis and its branches, is potentially life threatening, due to massive bleeding in the subarachnoid space upon rupture. In clinical practice, one minimally invasive surgical procedure is the implantation of a metallic stent to cover the aneurysm neck. This flow diverting device can reduce the flow into the aneurysm and enhance the prospect of thrombosis, a condition expected to reduce the risk of growth and rupture. The biomechanical and haemo-dynamic factors in stented and nonstented situations are studied by computational fluid dynamics. Unlike earlier models with straight or curved parent blood vessels, the aneurysm is now located near an arterial bifurcation. The influence of the aspect (depth to neck) ratio of the aneurysm on the flow dynamics will be emphasized, especially in the post-operation stages. More precisely, the maximum flow velocity, the variations of wall shear stress, the risk of stent migration and volumetric flow rate after endovascular treatment will be studied. Aneurysms with larger aspect ratios (i.e. smaller neck sizes for constant depth) generally pose a greater risk in terms of these flow parameters. These results will assist the applications and design of stents in future neurosurgical therapy. The approach is limited to a nonelastic model, without taking into account of questions like stent expansion and interaction with tissue.

关键词： Intracranial Aneurysm Endovascular Treatment Stent Aspect Ratio Computational Fluid Dynamics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The effects of stent porosity on the endovascular treatment of intracranial aneurysms located near a bifurcation

引用

Journal of Biomedical Science and Engineering 2013年第8期6卷 812-822页

作者： abraham yik-sau tang Hiu-Ning Chan Anderson Chun-On Tsang Gilberto Ka-Kit Leung Kar-Ming Leung Alfred Cheuk-Hang Yu Kwok-Wing Chow Department of Mechanical Engineering University of Hong Kong Hong Kong China Department of Neurosurgery Kwong Wah Hospital Hong Kong China Division of Neurosurgery Department of Surgery Li Ka Shing Faculty of Medicine University of Hong Kong Queen Mary Hos-pital Hong Kong China Medical Engineering Program Department of Electrical and Electronic Engineering University of Hong Kong Hong Kong China

Intracranial aneurysm occurs when a cerebral artery develops an abnormal sac-like dilatation, and will cause massive bleeding in the subarachnoid space upon rupture. Endovascular stenting is a minimally invasive procedure in which a flow-diverting stent is deployed to cover the aneurysm neck, thereby restricting blood from entering the aneurysm and reducing the risk of rupture. The stent porosity, a crucial factor determining the intra-aneurysmal hemodynamics following treatment, is investigated by computational fluid dynamics techniques. Based on the computational results, a low porosity stent will dramatically reduce the flow velocity and the flow rate inside the side branch vessel. Conversely, a high porosity stent may not provide adequate flow reduction inside the aneurysm, possibly causing treatment failure. An advisable range of optimal stent porosity would be 60% to 75%, which can drastically reduce the flow rate into the aneurysm while preserving enough blood flow for the side branch vessel. Clinically, deployment of two or more flow-diverting stents may not increase treatment efficacy but can potentially lead to adverse effects due to side-branch hypoperfusion. The present quantitative analysis can also provide practical insight for future stent design.

关键词： Intracranial aneurysm Endovascular Treatment Stent Stent Porosity Computational Fluid Dynamics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：