Impact of Stent Design on Intra-Aneurysmal Flow
Impact of Stent Design on Intra-Aneurysmal Flow
复制标题
支架设计对动脉瘤内血流的影响
DOI：
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发表时间：
2004
影响因子：
1.7
通讯作者：
D. A. Rüfenacht
中科院分区：
文献类型：
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作者：
Makoto Ohta;Miki Hirabayashi;S. Wetzel;P. Lylyk;H. Wata;Sadami Tsutsumi;D. A. Rüfenacht
除了为血管重建提供骨架外，用于脑动脉瘤治疗的支架植入还可以诱导血流重定向，从而降低动脉瘤腔内的涡流速度。此外，通过模拟模拟，支架的大小、孔隙率和细胞形状等特征会影响动脉瘤内血流的变化。这项计算机模拟研究的目的是在改变支架参数的情况下可视化侧壁动脉瘤整个颈部区域的血流模式。建立动脉瘤的三维计算机模型，载瘤动脉直径5 mm，动脉瘤直径10 mm。主动脉中线至动脉瘤中心点的距离为6.8 mm，颈长5 mm，宽3.6 mm，颈面积14mm2。在平均速度为290 mm/S、定常粘度为3.83cp、密度为1.0g/cm~3的定常流动中，求解了不可压缩的N-S方程。将两个平行的支架支架(尺寸：100μm，100μm，2.0 mm)置入动脉瘤颈平面。支架所占动脉瘤颈截面积的比例为2.83%。计算了三种不同选择的支架之间的分离，以及支架相对于血管轴线的两个方向(平行和垂直)中的每一个，通过动脉瘤颈部的速度分布。动脉瘤的血流模式是由远端颈动脉流入区和近端颈动脉流出区组成。在动脉瘤颈部放置支架后，动脉瘤的平均速度减慢。复位的程度和流经颈部的分布确实取决于支架支架的方向。当支架与载瘤血管轴线平行或垂直时，对穿过动脉瘤颈的平均速度有不同程度的影响。
In addition to providing a skeleton for vessel reconstruction, stent implantation as used for cerebral aneurysm treatment can induce flow redirection, thus reducing vortical flow velocities within the aneurysm cavity. Further, stent characteristics such as strut size, porosity and cell shape influence the changes in intra-aneurysmal flow by analog simulations. The purpose of this computer simulation study was to visualize the flow pattern over the entire neck area of a side wall aneurysm while changing the stent parameters. A 3-D computer model aneurysm was constructed to have a parent artery of 5 mm diameter and an aneurysm of 10 mm diameter. The distance between the midline of main artery and center point of the aneurysm was 6.8 mm, providing a neck length of 5 mm, a width of 3.6 mm, and a neck area of 14 mm 2. The simulations were carried out with a Finite Element Method based flow simulation package. The incompressible Navier -Stokes equation was solved for a steady flow with a mean speed of 290 mm/s, steady viscosity of 3.83 cp, and density of 1.0 g/cm3. Two parallel stent struts (dimensions: 100 μm m 100 μm m 2.0 mm) were introduced into the plane of the aneurysm neck. The fraction of the aneurysm neck cross-section occupied by the stent was 2.83% in all cases. The velocity distribution through the neck of the aneurysm was calculated for three different choices of separation between the struts for each of two orientations of the struts (parallel and perpendicular) relative to the vessel axis. The flow pattern in the aneurysm was composed of an inflow zone at the distal neck and of an outflow zone at the proximal neck. The placement of stent struts at the aneurysm neck resulted in a decrease in the mean speed in the aneurysm. The degree of reduction and the distribution of flow through the neck did depend on the orientation of the stent struts. The struts, when placed parallel or perpendicular to the parent vessel axis affected the mean speed through the aneurysm neck differently.