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背景:脑动脉瘤成为威胁人类生命的血管瘤之一,目前的治疗方法分别为血管内介入栓塞和开颅夹闭。但是这两种方法术后患者的复发率和死亡率普遍偏高。因此支架置入治疗脑动脉瘤的新思想被提出。目的:评估支架置入脑动脉瘤后对血流场特性参数的影响,为患者提供可行治疗方案。方法:回顾分析新疆医科大学附属医院的11例脑动脉瘤患者放射的CT影像数据,结合MIMICS软件,通过逆向工程建立脑动脉瘤柔性实体模型。将设计适配的支架模型置入脑动脉瘤中,并结合流体动力学理论及Fluent物理数值模型对脑动脉瘤进行双向流固耦合的血流场分析。最后对置入支架前后脑动脉瘤的动力学参数进行对比分析(壁面压力、血液速度矢量、血液流线、壁面剪切力、壁面变形量);在不同入口速度下分析置入支架后脑动脉瘤的血流场特性。结果与结论:(1)支架置入后脑动脉瘤最大壁面压力降低约为61.1%,支架周围血液流速及脑动脉瘤内部的血液速度明显减缓,设置2 000条血液流线的情况下进入脑动脉的流线数量减少约为75%,壁面最大剪切力降低79.3%左右,壁面最大变形量减少了一个数量等级;(2)设置血液入口流速分别为v1=0.1 m/s,v2=0.2 m/s,v3=0.3 m/s下,壁面压力呈现壁面剪切力上升趋势,壁面剪切力随着速度增加呈现逐渐增大状态,同时τzou(左侧瘤颈的剪切应力)<τzhong(脑动脉瘤处的剪切应力)<τyou(右侧瘤颈的剪切应力),血液流线主要集中在脑动脉瘤顶部,血液速度变化对壁面变形量的影响明显。(3)置入支架后脑动脉瘤的主要血流动力学参数均较未置入前得到明显改善;血流速度对脑动脉瘤的影响显著,在支架治疗过程中需要考虑在内。
Background: Cerebral aneurysms have become one of the hemangiomas that threaten human life. The current treatments are endovascular embolization and craniotomy occlusion. However, the postoperative recurrence and mortality of these two methods are generally high. Therefore, the new idea of stenting for the treatment of cerebral aneurysms has been proposed. OBJECTIVE: To evaluate the influence of stent implantation on cerebral arterial aneurysm and to provide feasible treatment for patients. Methods: CT images of 11 patients with cerebral aneurysm in Affiliated Hospital of Xinjiang Medical University were retrospectively analyzed. Combined with MIMICS software, a flexible solid model of cerebral aneurysm was established by reverse engineering. The designed scaffold model was placed into cerebral aneurysm, and the flow field analysis of cerebral aneurysm with two-way fluid-solid coupling was carried out based on the hydrodynamic theory and Fluent physical numerical model. Finally, the dynamic parameters of cerebral aneurysms before and after stent implantation were compared (wall pressure, blood velocity vector, blood streamline, wall shear force and wall deformation). At different entry velocities, Of the blood flow field characteristics. RESULTS AND CONCLUSION: (1) The maximal wall pressure of cerebral aneurysm was reduced by about 61.1% after stent implantation. The blood flow velocity around the stent and the blood velocity inside the cerebral aneurysm significantly slowed down. When 2 000 blood flow lines were set, the cerebral artery (2) Set the blood inlet velocity v1 = 0.1 m / s, v2 = 0.2 m, respectively. The flow rate of the blood is reduced by about 75%, the maximum shear force of the wall is reduced by 79.3%, and the maximum deformation of the wall is reduced by one order of magnitude. /s,v3=0.3 m / s, the wall pressure shows a rising trend of the wall shear force, and the wall shear force increases gradually with the increase of the velocity, and τzou (shear stress of the left neck) <τzhong ( Shear stress at the cerebral aneurysm) <τyou (shear stress of the right neck), blood flow mainly in the top of the cerebral aneurysm, blood velocity changes on the wall deformation significantly. (3) The major hemodynamic parameters of cerebral aneurysm after stent implantation were significantly improved compared with those before implantation. The blood flow velocity had a significant effect on cerebral aneurysm and should be considered in the treatment of stent.