【作者】 彭红梅； 赵洪明； 宋雨杰；

【Author】 PENG Hongmei;ZHAO Hongming;SONG Yujie;College of Mathematics and Physics,Inner Mongolia University for Nationalities;

【机构】 内蒙古民族大学数理学院；

【摘要】 目的通过建立的胸主动脉夹层模型,利用CFD方法进行血流动力学数值模拟,分析血流动力学因素对主动脉瘤及夹层病变的发生发展的影响。方法对从临床采集的患有主动脉瘤并发主动脉夹层患者的CT数据进行医学建模,经过光顺处理、网格划分及边界条件设置后,利用计算流体力学软件ANSYS FLUENT14.5计算一个心动周期内4个不同时刻主动脉病变内的血流速度、压强和壁面切应力的血流动力学变化情况。结果人体胸主动脉夹层破口处出现涡旋流动,随着血流入口速度的逐渐增大,胸主动脉夹层内的血液流速却始终保持接近零的速度,且破口位置的血液流动速度明显低于其周围的血液流速,主动脉夹层处的壁面切应力始终小于夹层周围的壁面切应力,且胸主动脉内侧壁面的压力低于外侧壁面。结论主动脉外侧壁面在较大压力作用下更易发生内膜破裂形成动脉瘤及并发夹层疾病,同时大的压力导致形成的动脉瘤直径不断变大,壁面不断变薄增加破裂风险,另外也将使夹层血管壁不断剥离沿降主动脉延伸。动脉瘤及夹层内较小的血流速度和切应力会导致血细胞及血液中脂肪粒的沉积,从而形成粥样硬化病变使血管壁失去弹性增加破裂风险。综上,血流动力学因素在主动脉夹层及动脉瘤疾病的发生、发展和破裂过程中起着非常重要的作用。更多还原

【Abstract】 Objective Through the established model of thoracic aortic dissection,CFD method was used to conduct hemodynamic numerical simulation to analyze the influence of hemodynamic factors on the occurrence and development of aortic aneurysm and dissection lesions.Methods The CT data of patients with aortic aneurysm complicated with aortic dissection collected from the clinic were modeled.After smoothing processing,meshing and boundary conditions setting,computational fluid dynamics software ANSYS FLUENT 14.5 was used to calculate the hemodynamic changes of blood flow velocity,pressure and wall shear stress in aortic diseases at four different moments in a cardiac cycle.Results Vortex flow appears at the breach of the thoracic aortic dissection in humans.With the gradual increase of the blood inlet velocity,the blood flow rate in the thoracic aortic dissection always keeps close to zero,and the blood flow velocity at the breach site is significantly lower regarding the blood flow rate around it,the wall shear stress at the aortic dissection is always smaller than the wall shear stress around the dissection,and the pressure on the inner wall surface of the thoracic aorta is lower than the outer wall surface.Conclusion Under the action of high pressure,the lateral wall of the aorta is more prone to intimal rupture,aneurysm formation and complicated dissection disease.At the same time,the large pressure leads to the continuous enlargement of the formed aneurysm,and the continuous thinning of the wall increases the risk of rupture.In addition,the dissection wall will continuously dissect and extend along the descending aorta.The blood flow velocity and shear stress in aneurysms and dissections are small,which can lead to the deposition of blood cells and fat particles deposited to form the atherosclerotic lesion,Make the blood vessel wall lose its elasticity and increase the risk of rupture.In conclusion,hemodynamic factors play a very important role in the occurrence,development and rupture of aortic dissection and aneurysm disease.更多还原