中国组织工程研究

中国组织工程研究 ›› 2016, Vol. 20 ›› Issue (38): 5722-5729.doi: 10.3969/j.issn.2095-4344.2016.38.015

• 材料生物相容性 material biocompatibility • 上一篇    下一篇

支架置入前脑动脉瘤血流场的特性分析

刘小月1，木合塔尔•克力木1，2，巨  刚1，王  晨1，李  卉1，孙海霞1
  

  1. 1新疆大学机械工程学院，新疆维吾尔自治区乌鲁木齐市  830047；2新疆医科大学附属医院，新疆维吾尔自治区乌鲁木齐市  830054
  • 收稿日期:2016-08-12 出版日期:2016-09-16 发布日期:2016-09-16
  • 通讯作者: 木合塔尔?克力木，硕士生导师，新疆大学机械工程学院，新疆维吾尔自治区乌鲁木齐市 830047
  • 作者简介:刘小月，女，1990年生，陕西省咸阳市人，汉族，新疆大学机械工程学院在读硕士，主要从生物流体力学方面的研究。
  • 基金资助:
    新疆维吾尔自治区自然科学基金(2013211A020)

Blood flow field characteristics of cerebral aneurysm before stent implantation

Liu Xiao-yue1, Muhetaer Kelimu1, 2, Ju Gang1, Wang Chen1, Li Hui1, Sun Hai-xia1
  

  1. 1School of Mechanical Engineering, Xinjiang University, Urumqi 830047, Xinjiang Uygur Autonomous Region, China; 2Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
  • Received:2016-08-12 Online:2016-09-16 Published:2016-09-16
  • Contact: Muhetaer Kelimu, Master’s supervisor, School of Mechanical Engineering, Xinjiang University, Urumqi 830047, Xinjiang Uygur Autonomous Region, China; Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
  • About author:Liu Xiao-yue, Studying for master’s degree, School of Mechanical Engineering, Xinjiang University, Urumqi 830047, Xinjiang Uygur Autonomous Region, China
  • Supported by:
    the Natural Science Foundation of Xinjiang Uygur Autonomous Region, No. 2013211A020

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238

被引次数

2

摘要：

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文题释义：
支架置入后血管再狭窄：再狭窄问题主要由于作为异物的支架置入人体血管并撑开后，对血管内壁细胞造成了一定的损伤，触发人体自愈功能，血管内壁的大量平滑肌再次从新组织朝损伤部位移动，同时支架置入一定时间后，血液内的血小板在支架表面汇聚并释放相应的因子，导致了支架置入血管后再狭窄问题的出现。
剪切应力：物体由于载荷、温度变化而变形，在它内部任一剪切面的两个方向出现的相互作用力，称为“内力”。内力的集度，即单位面积上受到的内力称为“应力”。应力可分解为垂直于截面(剪切面)的分量，称为“正应力”或“法向应力”；相切于截面(剪切面)的分量，称为“剪切应力”。

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。

关键词: 生物材料, 材料相容性, 脑动脉瘤, CT 影像, 血管内支架, 血流动力学, 流固耦合, 新疆维吾尔自治区自然科学基金

Abstract:

BACKGROUND: Cerebral aneurysm is a kind of mortal hemangioma, and its treatments such as endovascular embolization and clipping both cause high postoperative recurrence rate and mortality. So the stent implantation for cerebral aneurysm is coming into being.
OBJECTTVE: To evaluate the hemodynamic parameters after stent implantation into cerebral aneurysm and to provide a novel feasible strategy for clinical treatment.
METHODS: A retrospective analysis was preformed based on the CT image data of 11 patients with cerebral aneurysm from the Affiliated Hospital of Xinjiang Medical University. Firstly, the flexible and solid model of cerebral aneurysm was established by the MIMICS and reverse engineering. Secondly, the matching stent model was implanted into the cerebral aneurysm, and then the blood flow structure of cerebral aneurysm was analyzed by the fluid dynamics theory and the Fluent with the method of two-way flow solid coupling. Finally, comparative analysis of the kinetic parameters of cerebral aneurysm before and after implantation, including wall pressure, blood velocity, path line of the blood flow, wall shear stress, wall deformation was conducted, and blood flow characteristics after stent implantation were analyzed under different entrance velocity.
RESULTS AND CONCLUSION: After implantation, the wall surface pressure was reduced about 61.1%; the blood flow velocity around the stent and the inside of the cerebral aneurysm was decelerated obviously; under setting 2 000 lines of blood flow, the number of path line of blood flow into the cerebral aneurysm reduced about 75.0%, the maximum wall shear stress decreased about 79.3%, and the maximum wall deformation reduced to a lower level. The entrance velocity was respectively v1=0.1 m/s, v2=0.2 m/s, v3=0.3 m/s and the wall pressure was in a gradient ascent; the wall shear stress increased with the velocity, meanwhile, τzou (left neck of aneurysm) <τzhong (aneurysm )< τyou (right neck of aneurysm). The path lines of blood flow mainly concentrated in the top of the aneurysm, and the blood velocity markedly affected the surface deformation. These results indicate that main hemodynamic parameters are obviously improved after stent implantation into cerebral aneurysm, and the blood velocity should never be neglectful in the treatment process.

Key words: Hemangioma, Stents, Blood Flow Velocity, Hemodynamics, Tissue Engineering

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