Hazan Shenberger Sapir, Avrahami Idit
Department of Mechanical Engineering and Mechatronics, Ariel University, Ariel 40700, Israel.
Bioengineering (Basel). 2024 Feb 28;11(3):238. doi: 10.3390/bioengineering11030238.
Percutaneous mechanical circulatory support (MCS) devices are designed for short-term treatment in cases of acute decompensated heart failure as a bridge to transplant or recovery. Some of the known complications of MCS treatments are related to their hemodynamics in the aorta. The current study investigates the effect of MCS on the aortic flow. The study uses combined experimental and numerical methods to delineate complex flow structures. Particle image velocimetry (PIV) is used to capture the vortical and turbulent flow characteristics in a glass model of the human aorta. Computational fluid dynamics (CFD) analyses are used to complete the 3D flow in the aorta. Three specific MCS configurations are examined: a suction pump with a counterclockwise (CCW) rotating impeller, a suction pump with a clockwise (CW) rotating impeller, and a discharge pump with a straight jet. These models were examined under varying flow rates (1-2.5 L/min). The results show that the pump configuration strongly influences the flow in the thoracic aorta. The rotating impeller of the suction pump induces a dominant swirling flow in the aorta. The swirling flow distributes the incoming jet and reduces the turbulent intensity near the aortic valve and in the aorta. In addition, at high flow rates, the local vortices formed near the pump are washed downstream toward the aortic arch. Specifically, an MCS device with a CCW rotating impeller induces a non-physiological CCW helical flow in the descending aorta (which is opposite to the natural helical flow), while CW swirl combines better with the natural helical flow.
经皮机械循环支持（MCS）设备设计用于急性失代偿性心力衰竭的短期治疗，作为移植或恢复的桥梁。MCS治疗的一些已知并发症与其在主动脉中的血流动力学有关。本研究调查了MCS对主动脉血流的影响。该研究采用实验和数值相结合的方法来描绘复杂的流动结构。粒子图像测速技术（PIV）用于捕捉人体主动脉玻璃模型中的涡流和湍流特性。计算流体动力学（CFD）分析用于完成主动脉中的三维流动。研究了三种特定的MCS配置：带有逆时针（CCW）旋转叶轮的抽吸泵、带有顺时针（CW）旋转叶轮的抽吸泵以及带有直喷口的排出泵。这些模型在不同流速（1 - 2.5升/分钟）下进行了检查。结果表明，泵的配置对胸主动脉中的血流有强烈影响。抽吸泵的旋转叶轮在主动脉中诱导出占主导地位的旋流。旋流使进入的射流分布均匀，并降低了主动脉瓣附近和主动脉中的湍流强度。此外，在高流速下，泵附近形成的局部涡流被向下游冲向主动脉弓。具体而言，带有CCW旋转叶轮的MCS设备在降主动脉中诱导出非生理性的CCW螺旋流（与自然螺旋流相反），而CW旋流与自然螺旋流的结合更好。
