The influence of the angle of confluence on the flow in a vertebro-basilar junction model
The influence of the angle of confluence on the flow in a vertebro-basilar junction model
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DOI：
10.1016/0021-9290(95)00064-x
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发表时间：
1996-03-01
影响因子：
2.4
通讯作者：
Hoogstraten, HW
中科院分区：
文献类型：
--
作者：
Ravensbergen, J;Krijger, JKB;Hoogstraten, HW
在早期的工作中，已经证明椎基底关节模型中的弓形是高度三维的，其几何形状对血流动力学有很强的影响。椎基底关节的形态在个体之间是非常不同的。在一项对85个人类椎基底动脉连接的研究中，椎动脉之间的角度在10到160度之间变化。为了确定该几何参数对流动的影响，采用激光多普勒测速法对弓形结构进行了实验研究，并采用有限元软件包进行了数值研究。一系列的结模型被用于一系列合流角（45度、85度和125度）。可见合流角对二次流场的结构和强度有很大的影响。次级速度持续在下游很远的地方。此外，在顶部附近，存在一个低速区域。合流角越大，该区域越大，甚至可能发生回流。此外，研究了85个人椎基底动脉连接处动脉粥样硬化斑块的发生。只发现了一个优先位置：顶点，其他斑块似乎是随机分布的。尖角结的汇合角大小对尖头斑块的发生有显著影响（p = 0.006）。显然，大的汇流角是动脉粥样硬化的几何危险因素。
In earlier work, it was demonstrated that the Bow in models of the vertebro-basilar junction is highly three-dimensional and the geometry exerts a strong influence on the hemodynamics. The morphology of the vertebro-basilar junction is very variable amongst individuals. In a study of 85 human vertebro-basilar junctions, the angle between the vertebral arteries varied between 10 and 160 degrees.To determine how the flow is influenced by this geometrical parameter, the Bow is studied both experimentally, with laser Doppler velocimetry, and numerically, with a finite element package. A series of junction models is used with a range of confluence angles (45, 85 and 125 degrees). It appears that the angle of confluence has a strong influence on the structure and strength of the secondary flow field. The secondary velocities persist far downstream. Furthermore, near the apex, a region with low velocities is present. The larger the confluence angle is, the larger this region is, and even backflow may occur. In addition, the occurrence of atherosclerotic plaques in 85 human vertebrobasilar junctions is studied. Only one preferential location was found: the apex, the other plaques seem to be randomly distributed. The magnitude of the confluence angle of junctions with sharp-edged apices has a significant influence (p = 0.006) on the occurrence of a plaque at the apex. Apparently, a large confluence angle is a geometrical risk factor for atherosclerosis.