Osswald A, Karmonik C, Anderson J R, Rengier F, Karck M, Engelke J, Kallenbach K, Kotelis D, Partovi S, Böckler D, Ruhparwar A
Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany.
MRI Core, Houston Methodist Research Institute, Houston, TX, USA.
Eur J Vasc Endovasc Surg. 2017 Sep;54(3):324-330. doi: 10.1016/j.ejvs.2017.06.012. Epub 2017 Jul 14.
Retrograde aortic type A dissection (RTAD) is a known complication in patients with aortic type B dissection. The purpose of this computational fluid dynamics (CFD) study was to identify haemodynamic risk factors for the occurrence of RTAD.
Computed tomographic angiography (CTA) images of 10 patients with type B dissections, who subsequently developed a RTAD, were retrospectively analysed together with patients constituting a control group (n = 10) where no further vascular events after the initial type B dissection occurred. CFD simulations were conducted based on 3D surface models of the aortic lumen derived from CTA datasets. For both groups, pressures, velocity magnitudes and wall shear stress (WSS) were compared at the site of the future RTAD entry tear and the surrounding aortic wall.
WSS at the site of the future entry tear was significantly elevated compared with the surrounding wall (15.10 Pa vs. 5.15 Pa, p < .001) and was significantly higher in the RTAD group than in the control group (6.05 Pa, p < .002). Pressures and velocity magnitudes were not significantly elevated at the entry tear (3825.8 Pa, 0.63 m/s) compared with the aortic arch (3549.8 Pa, 0.50 m/s) or control group (3501.7 Pa, 0.62 m/s).
Increased WSS accompanies the occurrence of RTAD. The results merit the design for a prospective study to confirm whether WSS is a risk factor for the occurrence of RTAD.
逆行性A型主动脉夹层（RTAD）是B型主动脉夹层患者的一种已知并发症。本计算流体动力学（CFD）研究的目的是确定RTAD发生的血流动力学危险因素。
回顾性分析10例B型夹层患者的计算机断层血管造影（CTA）图像，这些患者随后发生了RTAD，并与一个对照组（n = 10）的患者一起进行分析，该对照组在初次B型夹层后未发生进一步的血管事件。基于从CTA数据集中导出的主动脉腔的3D表面模型进行CFD模拟。对两组患者，比较未来RTAD入口撕裂部位和周围主动脉壁处的压力、速度大小和壁面剪切应力（WSS）。
与周围壁相比，未来入口撕裂部位的WSS显著升高（15.10 Pa对5.15 Pa，p <.001），RTAD组显著高于对照组（6.05 Pa，p <.002）。与主动脉弓（3549.8 Pa，0.50 m/s）或对照组（3501.7 Pa，0.62 m/s）相比，入口撕裂处的压力和速度大小没有显著升高（3825.8 Pa，0.63 m/s）。
RTAD的发生伴随着WSS的增加。这些结果值得设计一项前瞻性研究，以确认WSS是否是RTAD发生的危险因素。
