1.四川大学 力学系;2.北京航空航天大学;3.四川大学 华西医院;4.四川文化产业职业学院
R 318. 01
摘要：目的 基于血流动力学分析，探究一例B型主动脉夹层腔内修复术(Thoracic endovascular aortic repair, TEVAR)后发生新发破口的原因。方法对1位B型主动脉夹层患者在TEVAR术后1月、6月、12月、24月定期复查主动脉CT血管造影检查(Computed tomography angiography，CTA)。基于各时期CTA影像，重建三维模型，进行形态学和血流动力学数值模拟分析。结果相比于术后1月，术后12月真腔直径增大了1.8倍，且主动脉整体扭曲度增大了16.67%；术后1、6、12月，在心脏收缩期新发破口处最大血流速度分别高于支架远端锚定区平均流速69.6%、33.7%、92.1%，最大壁面剪切应力分别为平均剪切力的2.52、2.32、3.52倍；此外，时均壁面切应力(Time-averaged wall shear stress,TAWSS)在术后1、6、12月最大值分别为平均时均壁面剪切应力的1.88、2.53、3.62倍。结论TEVAR术后新发破口处主动脉真腔直径存在明显突变，且持续增大，导致该处主动脉血流流速加快，内膜长期承受高壁面剪切应力，进而引起了新发破口。
Abstract: Objective Based on hemodynamic analysis, to investigate the cause of distal tear in Stanford type B aortic dissection after Thoracic endovascular aortic repair （TEVAR）. Methods A patient with type B aortic dissection was reexamined regularly with CTA at 1 month, 6 months, 12 months and 24 months after TEVAR. Based on the CTA images of four periods, four three-dimensional aorta models were reconstructed to perform morphological analysis and hemodynamic simulation. Results Compared with that at 1 month after TEVAR, the diameter of true lumen at 12 months after TEVAR increased by 1.8 times and the global distortion of aorta increased by 16.67%. At postoperative 1, 6 and 12 months, the maximum blood velocities at the new tear at systolic were 69.6%, 33.7% and 92.1% higher than the average ones at the distal landing zone, and the maximum wall shear stresses (WSSs) were 2.52,2.32 and 3.52 times of the average values respectively. In addition, the maximum time-averaged WSS (TAWSS) at 1, 6 and 12 months after TEVAR were 1.88, 2.53 and 3.62 times of the mean values respectively. Conclusions The morphology of the aorta remodeled following TEVAR, and a sudden change in the diameter of the true lumen occurred at the distal anchoring zone. As a result, the blood flow velocity in this area accelerated, and the intima was continuously exposed to high WSS, leading to a new distal tear.