背景：动脉瘤中置入支架后血液流动状态的改变，为研究支架置入后再狭窄的发生提供了前提和条件，而数值模拟分析是一种很好的技术手段。 目的：探究支架置入对个体化颅内动脉瘤血液动力学的影响，以及支架表面剪切应力的分布特征。 方法：依据1例颅内动脉瘤患者的CT影像数据，进行数据的提取、优化，建立个体化颅内动脉瘤实体化模型；设计矩形截面螺旋形支架的三维模型，并通过布尔运算，得到带有支架的动脉瘤模型，并通过对该模型支架表面剪切应力的分布情况来分析再狭窄发生的可能。 结果与结论：通过探究不同血流速度与血液黏度对支架表面剪切应力的影响发现，在同一个时刻中支架表面大于40 Pa的剪切应力区域，随血流速度和血液黏度的增大而增大；而剪切应力不足0.5 Pa的区域，随血液黏度的增大有所减小，当速度为0时分布最大。该支架对于动脉瘤的生长或破裂起到了抑制作用，但发生再狭窄的区域很大，需要对支架进行优化或从新选型，以使支架的剪切应力保持在0.5-40 Pa的理想范围之中，并保证在心动周期的不同时刻里剪切应力的脉动变化尽可能减小，以达到防止支架置入后发生血管内部的再狭窄目的。%BACKGROUND:Numerical stimulation technology is a good method to analyze blood flow changes after intracranial aneurysm stenting that oftenresult in restenosis. OBJECTIVE:To explore the hemodynamic effect of stent implantation on patient-specific intracranial aneurysm and the distribution of the wal shear stress on the stent surface. METHODS:Brain CT data from a patient with intracranial aneurysm were extracted and optimized to establish a patient-specific intracranial aneurysm materialization model. Meanwhile, a three-dimensional model of rectangular section spiral stent was designed to develop an aneurysm model with the stent by the method of boolean operation. Then, the possibility of restenosis was analyzed based on the distribution of wal shear stress on the surface of stent model. RESULTS AND CONCLUSION:The wal shear stress on the stent surface which was more than 40 Pa increasedalong with the increase of blood velocity and blood viscosity at the same moment. However, the wal shear stress on the stent surface which was less than 0.5 Pa decreased along with the increase of blood viscosity, and its distribution was the largest when the blood velocity was 0. This stent provides a new insight into the controling of the aneurysm growth and rupture, but the restenosis area is too large. In order to prevent restenosis, the stent need to be optimized or reselected to keep the desired shear stress values of 0.5 to 40 Pa, and meanwhile to minimize the pulsating change of wal shear stress during a cardiac cycle.
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