目的:本研究的目的是通过使用精确的3D几何形状和逼真的,创建鸟嘴效应模拟来研究不同程度的胸主动脉支架移植物突出延伸中的血流效应,非线性,使用计算机辅助软件SolidWorks的弹性生物力学模型。
方法:使用SolidWorks对真实患者的计算机断层扫描(CT)扫描对主动脉弓进行3D分割。对三个模型进行了参数分析:(A)无支架的主动脉弓,(B)3毫米鸟嘴配置,和(C)6.5毫米鸟嘴配置。流速,压力,涡度,壁面剪应力(WSS),和时间平均WSS进行了评估。
结果:模型A中的流速在头臂动脉口区域保持相对恒定且较低,在左锁骨下动脉增加了一倍。相反,模型B和C显示左锁骨下动脉的速度降低52.3%。此外,模型B显示在鸟喙区域以下的速度下降了82.7%,而模型C在该区域显示下降80.9%。与模型A相比,模型B和C中的主动脉上分支内的压力更高。涡度仅出现在降主动脉的水平,主动脉弓有低至无涡度。相比之下,模型B和C在鸟喙区域内的平均涡度为241.4Hz。关于WSS,模型A,模型B在收缩期高峰期共享相似的WSS,在主动脉弓,和鸟喙区,而在这些区域,模型C的WSS平均增加了5Pa。
结论:在目前的模拟中,较低的速度,更高的压力,旋涡,在鸟喙区周围观察到WSS,主动脉弓,和主动脉上血管。
OBJECTIVE: The objective of this study was to investigate the flow effects in different degrees of thoracic aortic stent graft protrusion extension by creating bird beak effect simulations using accurate 3D geometry and a realistic, nonlinear, elastic biomechanical model using computer-aided software SolidWorks.
METHODS: Segmentation in 3D of an aortic arch from a computed tomography (CT) scan of a real-life patient was performed using SolidWorks. A parametric analysis of three models was performed: (A) Aortic arch with no stent, (B) 3 mm bird-beak configuration, and (C) 6.5 mm bird-beak configuration. Flow velocity, pressure, vorticity, wall shear stress (WSS), and time average WSS were assessed.
RESULTS: The flow velocity in Model A remained relatively constant and low in the area of the ostium of the brachiocephalic artery and doubled in the left subclavian artery. On the contrary, Models B and C showed a decrease in velocity of 52.3 % in the left subclavian artery. Furthermore, Model B showed a drop in velocity of 82.7% below the bird-beak area, whereas Model C showed a decline of 80.9% in this area. The pressure inside the supra-aortic branches was higher in Model B and C compared with Model A. In Model A, vorticity only appeared at the level of the descending aorta, with low to non-vorticity in the aortic arch. In contrast, Models B and C had an average vorticity of 241.4 Hz within the bird beak area. Regarding WSS, Model A, and Model B shared similar WSS in the peak systolic phase, in the aortic arch, and the bird beak area, whereas Model C had an increased WSS by 5 Pa on average at these zones.
CONCLUSIONS: In the present simulations\' lower velocities, higher pressures, vortices, and WSS were observed around the bird beak zone, the aortic arch, and the supra-aortic vessels.