下肢截肢水平对主动脉血流动力学影响的数值研究

Effect of lower limb amputation level on aortic hemodynamics:a numerical study

已有研究发现,下肢截肢患者心血管疾病发病率显著高于正常人,但少有学者从血流动力学角度研究下肢截肢与心血管疾病之间的关系。本文采用数值仿真,通过改变外周阻抗和电容模拟不同截肢水平,研究截肢对主动脉血流动力学环境的影响。结果发现,截肢后主动脉血压升高,肾下腹主动脉时均壁面切应力降低,且左右侧壁振荡剪切指数呈不对称分布;截肢侧髂动脉时均壁面切应力降低且振荡剪切指数增大;同时随截肢水平提高,上述变化更加显著,增加了截肢者患动脉粥样硬化与腹主动脉瘤的风险。本文初步揭示了下肢截肢对心血管疾病的影响规律,为截肢后康复训练设计与心血管疾病治疗方案优化提供理论指导。

It has been found that the incidence of cardiovascular disease in patients with lower limb amputation is significantly higher than that in normal individuals,but the relationship between lower limb amputation and the episodes of cardiovascular disease has not been studied from the perspective of hemodynamics.In this paper,numerical simulation was used to study the effects of amputation on aortic hemodynamics by changing peripheral impedance and capacitance.The final results showed that after amputation,the aortic blood pressure increased,the time averaged wall shear stress of the infrarenal abdominal aorta decreased and the oscillatory shear index of the left and right sides was asymmetrically distributed,while the time averaged wall shear stress of the iliac artery decreased and the oscillatory shear index increased.The changes above were more significant with the increase of amputation level,which will result in a higher incidence of atherosclerosis and abdominal aortic aneurysm.These findings preliminarily revealed the influence of lower limb amputation on the occurrence of cardiovascular diseases,and provided theoretical guidance for the design of rehabilitation training and the optimization of cardiovascular diseases treatment.