中央分流术中血管弹性壁和刚性壁对血管中血流动力学的影响  

Hemodynamic comparison between elastic and rigid vessels for the central shunt

作　　者：王枫[1] 刘有军[1] 丁金立[1] 白帆[1] 赵夕[1] 任晓辰[1] 

机构地区：[1]北京工业大学生命科学与生物工程学院,北京100124

出　　处：《医用生物力学》2013年第6期622-628,共7页Journal of Medical Biomechanics

基　　金：国家自然科学基金资助项目(11172016;10872013);北京市自然科学基金资助项目(3092005);北京市自然科学基金重点项目(KZ201210005006);高等学校博士学科点专项科研基金资助课题(20111103110012)

摘　　要：目的通过数值模拟仿真研究中央分流手术(central shunt,CS)的血流动力学环境,并分别研究弹性与刚性血管壁条件对其血管内血流动力学参数分布的影响。方法建立两个理想化的CS搭桥模型,其中一个假设为刚性血管壁,另一个为弹性血管壁。利用有限元方法进行数值计算,其中弹性血管壁模型采用流固耦合方法。结果两个模型中的流速和压力分布总体大致相同。刚性血管壁模型中大约有68.9%血液从主动脉分流进入肺动脉中,弹性血管壁模型中该值增加到了70%。弹性模型和刚性模型中搭桥血管两端的压降分别为7.668 8 kPa和7.222 3 kPa。弹性模型中搭桥管各处的横截面积有一定变化,最大变化率约为2.2%,出现在近心端吻合口处。提取两个模型中的5个关键区域进行壁面切应力比较,其数值差别最多约为16.1%。结论总体来说两个模型的血液流动形态没有大的改变;血管的弹性因素轻微影响了流量的分布和搭桥管两端的压降;搭桥管上血管的弹性对近心段吻合口处的影响高于对远心端吻合口处的影响。在CS术治疗法洛四联症的数值模拟仿真中血管壁为刚性这一假设是可以接受的,而流固耦合的数值模拟将得到更为可信的仿真结果。Objective To study the hemodynamics of central shunt （CS） by numerical simulation and investigate the effects of the elastic and rigid vessel wall on distributions of hemodynamic parameters in the vessel. Methods Two idealized CS models were constructed, one with a rigid wall （the rigid model） and the other with an elastic wall （the elastic model）. Numerical calculation was conducted by the finite element method, and the elastic model adopted the fluid structure interaction. Results The distribution of flow velocity and pressure in both models were generally the same. About 68.9% of the aortic blood was directed into the pulmonary artery for the rigid model, as compared to 70% for the elastic model. The pressure drops within the shunt for the elastic model and rigid model were about 7.668 8 kPa and 7.222 3 kPa, respectively. The maximum variation in the average cross sections along the shunt was about 2.2% for the elastic model, appearing at the proximal end to side （ETS） anastomosis. The maximum difference of wall shear stress （WSS） between the two models at five key regions of each was about 16.1%. Conclusions Generally, the global flow structure in both the CS models remains unchanged; the elasticity of the vessel wall slightly influenced the flow distributions and pressure drop of the shunt; the effect from elasticity of the vessel wall on average cross sections along the shunt was higher at the proximal ETS anastomosis than that at the distal ETS anastomosis; the hypothesis that the vessel wall is rigid is acceptable in CS numerical simulations for the treatment of tetralogy of Fallot （TOF）. However, the coupling of flow dynamics and wall mechanics may lead to a more reliable simulation result in the CS.

关 键 词：法洛四联症 流固耦合 中央分流术 血流动力学 数值模拟 

分 类 号：R318.01[医药卫生—生物医学工程]