School of Medicine and Health Sciences,Tecnologico de Monterrey, Monterrey, México.
School of Engineering and Sciences, Tecnologico de Monterrey, Monterrey, México.
Vasc Endovascular Surg. 2024 Aug;58(6):595-601. doi: 10.1177/15385744241247272. Epub 2024 Apr 12.
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.
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.
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.
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.
本研究旨在通过使用准确的 3D 几何形状和真实的非线性弹性生物力学模型，利用计算机辅助软件 SolidWorks 创建鸟嘴效应模拟，研究不同程度胸主动脉支架移植物突出延伸的流动效应。
使用 SolidWorks 对来自真实患者 CT 扫描的主动脉弓进行 3D 分段。对三个模型进行参数分析：（A）无支架主动脉弓，（B）3mm 鸟嘴构型，（C）6.5mm 鸟嘴构型。评估了流速、压力、涡度、壁面切应力（WSS）和平均时间 WSS。
模型 A 中的流速在头臂动脉口区域相对保持恒定且较低，而在左锁骨下动脉中增加了一倍。相反，模型 B 和 C 显示左锁骨下动脉中的速度降低了 52.3%。此外，模型 B 在鸟嘴区域下方的速度下降了 82.7%，而模型 C 在此区域的速度下降了 80.9%。模型 B 和 C 中的超上分支内压力高于模型 A。在模型 A 中，涡度仅出现在降主动脉水平，而在主动脉弓中涡度较低或不存在。相比之下，模型 B 和 C 在鸟嘴区域内的平均涡度为 241.4Hz。关于 WSS，模型 A 和模型 B 在主动脉弓和鸟嘴区域的峰值收缩期具有相似的 WSS，而模型 C 在这些区域的平均 WSS 增加了 5Pa。
在本模拟中，较低的速度、较高的压力、涡度和 WSS 出现在鸟嘴区域、主动脉弓和超上血管周围。
