Zhang Jiafeng, Han Dong, Chen Zengsheng, Wang Shigang, Sun Wenji, Griffith Bartley P, Wu Zhongjun J
From the Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.
Fischell Department of Bioengineering, A. James Clark School of Engineering, University of Maryland, College Park, Maryland.
ASAIO J. 2024 Dec 1;70(12):1085-1093. doi: 10.1097/MAT.0000000000002242. Epub 2024 May 19.
Thrombotic and bleeding events are the most common hematologic complications in patients with mechanically assisted circulation and are closely related to device-induced platelet dysfunction. In this study, we sought to link computational fluid dynamics (CFD) modeling of blood pumps with device-induced platelet defects. Fresh human blood was circulated in circulatory loops with four pumps (CentriMag, HVAD, HeartMate II, and CH-VAD) operated under a total of six clinically representative conditions. Blood samples were collected and analyzed for glycoprotein (GP) IIb/IIIa activation and receptor shedding of GPIbα and GPVI. In parallel, CFD modeling was performed to characterize the blood flow in these pumps. Numerical indices of platelet defects were derived from CFD modeling incorporating previously derived power-law models under constant shear conditions. Numerical results were correlated with experimental results by regression analysis. The results suggested that a scalar shear stress of less than 75 Pa may have limited contribution to platelet damage. The platelet defect indices predicted by the CFD power-law models after excluding shear stress <75 Pa correlated excellently with experimentally measured indices. Although numerical prediction based on the power-law model cannot directly reproduce the experimental data. The power-law model has proven its effectiveness, especially for quantitative comparisons.
血栓形成和出血事件是机械辅助循环患者中最常见的血液学并发症，并且与装置诱导的血小板功能障碍密切相关。在本研究中，我们试图将血泵的计算流体动力学（CFD）建模与装置诱导的血小板缺陷联系起来。新鲜人血在带有四个泵（CentriMag、HVAD、HeartMate II和CH-VAD）的循环回路中循环，这些泵在总共六种具有临床代表性的条件下运行。采集血样并分析糖蛋白（GP）IIb/IIIa激活以及GPIbα和GPVI的受体脱落情况。同时，进行CFD建模以表征这些泵中的血流情况。血小板缺陷的数值指标源自CFD建模，该建模纳入了先前在恒定剪切条件下推导的幂律模型。通过回归分析将数值结果与实验结果相关联。结果表明，小于75 Pa的标量剪切应力对血小板损伤的影响可能有限。排除剪切应力<75 Pa后，CFD幂律模型预测的血小板缺陷指标与实验测量指标高度相关。虽然基于幂律模型的数值预测不能直接重现实验数据，但幂律模型已证明其有效性，特别是在定量比较方面。
