基于个体化逆向工程和双向流固耦合模型的B型主动脉夹层数值模拟血流分析  

Numerical simulation study of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction

作　　者：张韬[1] 郭红斌[1] 李伟浩[1] 李伟[1] 张学民[1] 李清乐[1] 张小明[1] Zhang Tao;Guo Hongbin;Li Weihao;Li Wei;Zhang Xuemin;Li Qingle;Zhang Xiaoming(Department of Vascular Surgery, Peking University People′s Hospital, Beijing 100044, China)

机构地区：[1]北京大学人民医院血管外科,北京100044

出　　处：《中华医学杂志》2019年第2期142-147,共6页National Medical Journal of China

基　　金：北京市科技计划项目(Z151100004015142).

摘　　要：目的建立基于个体化逆向工程和双向流固耦合模型的B型主动脉夹层数值模拟模型,探讨计算流体力学技术在主动脉夹层重塑研究中的应用价值。方法获取北京大学人民医院血管外科B型主动脉夹层患者手术前、第一破口封堵后1周、第一破口封堵后6年和远端破口封堵后3个月的4次CT检查资料,使用Mimics逆向工程重建主动脉夹层三维模型,经Geomagic平滑化后运用ANSYS流体力学模块构建基于双向流固耦合模型进行主动脉夹层血流动力学数值模拟。分析血流动力学参数与主动脉夹层重塑之间的关系。结果成功建立基于个体化逆向工程和双向流固耦合模型的B型主动脉夹层数值模拟模型。主动脉弓远段与胸降主动脉连接处大弯侧存在血流压强峰值区。主动脉夹层假腔的壁应力远高于真腔,壁应力峰值分布在假腔的边缘处及破口附近。成功封堵第一破口后,夹层假腔流线明显减少,剩余腹主动脉下段残余假腔血流自左髂总动脉破口逆行向上灌注,并于假腔顶部形成涡流,有利于夹层血栓化重塑。第二破口位置残留假腔压力持续高于真腔,与动脉瘤形成相关。结论基于逆向工程个体化设计的双向流固耦合主动脉夹层数值模拟模型能够揭示B型主动脉夹层相对真实的血流动力和管壁应力特征。Objective To construct computational fluid model of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction, and evaluate the application of computational fluid model on aortic remodeling of type B aortic dissection. Methods Consecutive computed tomographic angiograph data was acquired from a patient with type B aortic dissection at initial diagnosis, 1 week and 6 years after endovascular repair of primary tear entry and 3 months after endovascular repair of distal tear erosion. Three-dimensional model of aortic dissection was reversely reconstructed by Mimics, and then the model was smoothened by Geomagic. Computational fluid dynamic numerical simulation was performed in ANSYS by the means of two-way fluid-structure interaction, and the relation between blood dynamic characteristic and thrombosed remodeling of type B aortic dissection was evaluated. Results The computational fluid model of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction method was successfully constructed. Local peak of blood pressure on the convex surface of junction at aortic arch and descending aorta was found. The wall stress was much higher at the false lumen than that at the true lumen, and the peak of wall stress converged on the edge and tear entry of false lumen. After the exclusion of proximal tear entry, the blood streamline was decreased significantly and flowed reversely. Blood flow in the remaining false lumen was retrograded from the entry at left iliac artery and formed turbulence at the top of false lumen, which was benefit for dissection thrombus remodeling. The higher pressure at the false lumen was associated with the new formation of aortic aneurysm at the distal tear. Conclusion The computational fluid model of aortic dissection based on patient-specific reverse engineering and fluid-structure interaction method can successfully reveal the relatively truly blood dynamic and wall pressure characteristic of type B aortic dissection

关 键 词：流体力学 动脉瘤 夹层 逆向工程 流固耦合 

分 类 号：R654.2[医药卫生—外科学]