Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran.
Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran.
World Neurosurg. 2024 May;185:e317-e341. doi: 10.1016/j.wneu.2024.01.159. Epub 2024 Feb 5.
Arteriovenous malformation is a disease of the vascular system that occurs mainly in the cerebral arteries and spine. Numerical simulation as a powerful method is used to investigate the Cerebral Arteriovenous Malformation hemodynamic after occlusion of the abnormality step by step by embolization.
The computed tomography (CT) Angiographic imaging data of 2 patients are used and a geometric model is extracted by the Mimics software. Numerical simulation of blood flow is performed in both Newtonian and non-Newtonian models. The Navier-Stokes and continuity governing equations are solved by a finite element method using the COMSOL Multiphysics software (the commercial computational fluid dynamics (CFD) simulation software). To validate the numerical results, the real data on blood flow rate in the feeding artery and draining veins are used, as well as angiographic images at different times.
Regarding the comparison of pressure contours for different occlusions of 0, 30, 50, and 90%, by increasing the amount of occlusion in the nidus, there is an increase in the blood pressure. Regarding the comparison of the blood flow velocity in the feeding artery, draining veins, and inside the AVM nidus for Newtonian and non-Newtonian models, there is a significant difference between these 2 simulations in vessels with smaller dimensions (such as vessels inside the nidus).
By increasing the amount of nidus occlusion, the blood pressure is increased, so the blood supply process is better. According to a significant difference between the Newtonian and non-Newtonian simulations in vessels with smaller dimensions (such as vessels inside the nidus), therefore, non-Newtonian simulation should be done for different occlusions of 30, 50, and 90%.
动静脉畸形是一种主要发生在脑动脉和脊柱的血管系统疾病。数值模拟作为一种强大的方法，用于通过逐步栓塞对异常的脑动静脉畸形进行闭塞后的血流动力学研究。
使用 2 名患者的计算机断层扫描（CT）血管造影成像数据，并使用 Mimics 软件提取几何模型。在牛顿和非牛顿模型中进行血流数值模拟。使用 COMSOL Multiphysics 软件（商业计算流体动力学（CFD）模拟软件）通过有限元方法求解纳维-斯托克斯和连续性控制方程。为了验证数值结果，使用了供血动脉和引流静脉中的真实血流率数据以及不同时间的血管造影图像。
关于不同闭塞程度（0、30、50 和 90%）的压力轮廓比较，随着病灶内闭塞量的增加，血压会升高。关于牛顿和非牛顿模型中供血动脉、引流静脉和动静脉畸形病灶内血流速度的比较，在较小尺寸的血管（如病灶内血管）中，这两种模拟之间存在显著差异。
随着病灶闭塞量的增加，血压升高，因此供血过程更好。根据较小尺寸血管（如病灶内血管）中牛顿和非牛顿模拟之间的显著差异，因此应该对 30、50 和 90%的不同闭塞程度进行非牛顿模拟。
