个性化主动脉夹层及其搭桥术的流固耦合数值模拟

Fluid-structure interaction simulation of patient-specific aortic dissection and its bypass grafting

目的研究不同搭桥方式对不同假腔型式的Debakey Ⅲ型主动脉夹层模型治疗效果的影响。方法依据主动脉夹层患者的CT图像,采用Mimics医学图像处理软件进行模型重建,并利用计算机辅助手段建立升-腹和锁-腹两种方式的旁路搭桥模型,进行流固耦合数值模拟计算,比较不同模型的血流动力学差异。结果实施两种方式的旁路搭桥转流术后,通腔型式模型的血液流量、血流平均与最大速度均有不同程度的降低。同时升-腹搭桥后血液最大压力和血管壁位移均减小,而锁-腹搭桥后却增加;盲腔型式模型的上述血流动力学参数在搭桥后均降低,且升-腹搭桥式模型的降幅更大。结论升-腹搭桥方式对通腔和盲腔两种假腔型式主动脉夹层有更好的治疗效果,借助数值模拟的结果可以更好地解释搭桥手术对主动脉夹层的影响,并确立搭桥手术的科学有效性和临床实用性。

Objective To investigate the effects of different bypass grafting for treating DeBakey Ⅲ aortic dissection.Methods The patient-specific models of DeBakey Ⅲ aortic dissection based on CT images were reconstructed by using Mimics software,and two bridge models of bypassing between ascending aorta and abdominal aorta （AA）,and between left subclavian artery and abdominal aorta （LA） were established by computer-aided method,respectively.Then numerical simulations were performed by using fluid-structure interaction （FSI） method to compare hemodynamic differences of these two models.Results After bypass surgery,the mass flow,mean and maximum velocities of the through lumen models were reduced to different degrees.Meanwhile,both the maximum blood pressures and displacements of the vessel walls of AA models were decreased,but those of LA models were increased.In contrast,all the above-mentioned hemodynamic parameters of the blind lumen models were decreased,especially for AA models.Conclusions The AA bypassing is a better treatment for DeBakey Ⅲ aortic dissection of through lumen and blind lumen.The therapeutic effects can be easily explained through simulation results,to ensure the scientific validity and clinical utility of bypassing.