Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Pauwelsstr. 20, 52074, Aachen, Germany.
Clinic for Diagnostic and Interventional Neuroradiology, University Hospital Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
Cardiovasc Eng Technol. 2023 Jun;14(3):393-403. doi: 10.1007/s13239-023-00660-8. Epub 2023 Feb 22.
Acute ischemic stroke is a life-threatening emergency caused by an occlusion of a cerebral artery through a blood clot. Aspiration thrombectomy is an endovascular therapy for the removal of vessel occlusions. However, open questions regarding the hemodynamics during the intervention remain, motivating investigations of blood flow within cerebral arteries. In this study, we present a combined experimental and numerical approach to analyze hemodynamics during endovascular aspiration.
We have developed an in vitro setup for investigations of hemodynamic changes during endovascular aspiration within a compliant model of patient-specific cerebral arteries. Pressures, flows, and locally resolved velocities were obtained. In addition, we established a computational fluid dynamics (CFD) model and compared the simulations during physiological conditions and in two aspiration scenarios with different occlusions.
Flow redistribution within cerebral arteries after ischemic stroke is strongly dependent on the severity of the occlusion and on the volume flow extracted by endovascular aspiration. Numerical simulations exhibit an excellent correlation of R = 0.92 for flow rates and a good correlation of R = 0.73 for pressures. Further on, the local velocity field inside the basilar artery had a good agreement between CFD model and particle image velocimetry (PIV) data.
The presented setup allows for in vitro investigations of artery occlusions and endovascular aspiration techniques on arbitrary patient-specific cerebrovascular anatomies. The in silico model provides consistent predictions of flows and pressures in several aspiration scenarios.
急性缺血性脑卒中是一种危及生命的紧急情况，由大脑动脉中的血栓阻塞引起。抽吸血栓切除术是一种血管内治疗方法，用于清除血管阻塞。然而，介入过程中的血流动力学仍存在一些悬而未决的问题，这促使我们对大脑动脉内的血流进行研究。在本研究中，我们采用了一种结合实验和数值的方法来分析血管内抽吸过程中的血液动力学。
我们开发了一种体外装置，用于研究在符合患者特定大脑动脉模型的血管内抽吸过程中血液动力学的变化。获得了压力、流量和局部分辨率的速度。此外，我们建立了一个计算流体动力学（CFD）模型，并比较了生理条件下和两种不同闭塞情况下的抽吸模拟。
缺血性脑卒中后大脑动脉内的血流重新分配强烈依赖于闭塞的严重程度和血管内抽吸提取的血流量。数值模拟显示，流量的相关系数 R=0.92，压力的相关系数 R=0.73。此外，基底动脉内的局部速度场在 CFD 模型和粒子图像测速（PIV）数据之间具有很好的一致性。
所提出的装置允许在体外研究动脉阻塞和血管内抽吸技术在任意患者特定的脑血管解剖结构上的应用。该计算机模型在几种抽吸情况下提供了一致的流量和压力预测。
