Moulakakis Konstantinos G, Kakisis John, Gonidaki Eleni, Lazaris Andreas M, Tsangaris Sokrates, Geroulakos George, Manopoulos Christos
1 Department of Vascular Surgery, Medical School, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece.
2 Biofluid Mechanics and Biomedical Engineering Laboratory, Fluids Section, School of Mechanical Engineering, National Technical University of Athens, Greece.
Vasc Endovascular Surg. 2019 Oct;53(7):572-582. doi: 10.1177/1538574419867531. Epub 2019 Aug 5.
BACKGROUND-AIM: Limited data exist concerning the fluid dynamic changes induced by endovascular aortic repair with fenestrated and chimney graft modalities in pararenal aneurysms. We aimed to investigate and compare the wall shear stress (WSS) and flow dynamics for the branch vessels before and after endovascular aortic repair with fenestrated and chimney techniques.
Modeling was done for patient specific pararenal aortic aneurysms employing fenestrated and chimney grafts (Materialise Mimics 10.0) before and after the endovascular procedure, using computed tomography scans of patients. Surface and spatial grids were created using the ANSYS CFD meshing software 2019 R2. Assessment of blood flow, streamlines, and WSS before and after aneurysm repair was performed.
The endovascular repair with chimney grafts leaded to a 43% to 53% reduction in perfusion in renal arteries. In fenestrated reconstruction, we observed a 15% reduced perfusion in both renal arteries. In both cases, we observed a decrease in the recirculation phenomena of the aorta after endovascular repair. Concerning the grafts of the renal arteries, we observed in both the transverse and longitudinal axes low WSS regions with simultaneous recirculation of the flow 1 cm distal to the ostium sites in both aortic graft models. High WSS regions appeared in the sites of ostium.
We observed reduced renal perfusion in chimney grafts compared to fenestrated grafts, probably caused by the long and kinked characteristics of these devices.
背景-目的：关于采用开窗和烟囱式移植物进行肾周动脉瘤血管内主动脉修复所引起的流体动力学变化的数据有限。我们旨在研究和比较采用开窗和烟囱技术进行血管内主动脉修复前后分支血管的壁面剪应力（WSS）和血流动力学。
利用患者的计算机断层扫描，对采用开窗和烟囱式移植物的患者特异性肾周主动脉瘤在血管内手术前后进行建模（Materialise Mimics 10.0）。使用ANSYS CFD网格划分软件2019 R2创建表面和空间网格。对动脉瘤修复前后的血流、流线和WSS进行评估。
采用烟囱式移植物进行血管内修复导致肾动脉灌注减少43%至53%。在开窗重建中，我们观察到双侧肾动脉灌注减少15%。在这两种情况下，我们都观察到血管内修复后主动脉的再循环现象减少。关于肾动脉移植物，在两种主动脉移植物模型中，我们在肾动脉开口处远端1 cm处的横向和纵向轴上均观察到低WSS区域，同时伴有血流再循环。高WSS区域出现在开口部位。
与开窗式移植物相比，我们观察到烟囱式移植物的肾灌注减少，这可能是由这些装置的长而弯曲的特性所致。
