装置引起的血液损伤有助于溶血,心室辅助装置(VAD)支持的患者血栓形成和出血并发症。这项研究旨在使用多指标方法来了解设备如何导致血液损伤,并确定VAD中血液损伤的“热点”。
选择计算流体动力学(CFD)方法来研究五种临床VAD的血流动力学特征(Impella5.0,UltraMag,CHVAD,HVAD,和HeartMateII)在相同的临床支持条件下(流速为4.5L/min,压头约75mmHg)。一种包括血流动力学参数的多指标综合评价方法,溶血模型,使用血栓形成电位模型和出血概率模型分析这些VAD的血液损伤并评估其血液动力学性能和血液相容性.
模拟结果表明,50Pa至100Pa的剪切应力在Impella5.0,UltraMag和CHVAD的血液损伤中起主要作用,而HVAD和HeartMateII的血液损伤主要是由大于100Pa的剪切应力引起的。在Impella5.0中,停留时间不是血液损伤的主要因素,并且在UltraMag和CHVAD中也对血液损伤的贡献有限,而它在提高HVAD和HeartMateII的血栓形成潜力方面起着关键作用。所有这些VAD的高溶血风险和高出血概率区域的分布相似,而高血栓潜在区域的分布部分重叠。对于Impella5.0,存在高溶血和出血风险的区域主要在叶尖间隙和扩散器区域。高血栓潜在区域几乎不存在.对于UltraMag,高溶血区域,在进气管的两个角落发现了出血和血栓形成的可能性,次级流动通道,和叶轮的眼睛。对于CHVAD,溶血的高危区域,出血和血栓形成主要在二级流道的内侧和叶轮通道的中间区域。狭窄的流体动力间隙和叶轮通道有很高的溶血和出血风险,转子和导向锥之间的间隙和流体动力间隙具有很高的血栓形成潜力。对于HeartMateII,在矫直机的近壁区域发现了高溶血风险和出血概率的区域,叶尖间隙和扩散器域。入口和出口管的角落以及矫直器和扩散器区域具有高血栓形成潜力。
溶血的风险,这五个VAD的出血和血栓形成,以递增的顺序,是Impella5.0,UltraMag,CHVAD,HVAD,《心灵伴侣II》转子机械运动引起的流动损失,混乱的流动和狭窄的间隙增加了所有这些VAD的血液损伤。多指标分析可以对VAD性能进行综合评价,提高了CFD的评价精度。
Device-induced blood damage contributes the hemolysis, thrombosis and bleeding complications in patients supported with ventricular assist device (VAD). This study aims to use a multi-indicator method to understand how devices causes blood damage and identify the \"hot spots\" of blood trauma within VADs.
Computational fluid dynamics (CFD) methods were chosen to investigate the hemodynamic features of five clinical VADs (Impella 5.0, UltraMag, CHVAD, HVAD, and HeartMate II) under the same clinical support condition (flow rate of 4.5L/min, pressure head around 75 mmHg). A comprehensive multi-indicator evaluation method including hemodynamic parameters, hemolysis model, thrombotic potential model and bleeding probability model was used to analyze blood damage and assess the hemodynamic performance and hemocompatibility of these VADs.
Simulation results show that shear stress from 50 Pa to 100 Pa plays a major role in blood damage in Impella 5.0, UltraMag and CHVAD, while blood damage in HVAD and HeartMate II is mainly caused by shear stress greater than 100 Pa. Residence time was not the main factor for blood damage in Impella 5.0, and also makes a limited contribution to blood trauma in UltraMag and CHVAD, while it takes a critical role in elevating thrombotic potential in HVAD and HeartMate II. The distribution of regions of high hemolysis risk and high bleeding probability was similar for all these VADs and partially overlapped for high thrombotic potential regions. For Impella 5.0, regions with high hemolysis and bleeding risk were found mainly in the blade tip clearance and diffuser domains, high thrombotic potential regions were almost absent. For UltraMag, regions with high hemolysis, bleeding and thrombosis potential were found in two corners of the inlet pipe, the secondary flow passage, and the impeller eye. For CHVAD, the high-risk regions for hemolysis, bleeding and thrombosis are mainly in the inner side of the secondary flow passage and the middle region of the impeller passage. The narrow hydrodynamic clearance and impeller passage had a high risk of hemolysis and bleeding, and the clearance between the rotor and guide cone and the hydrodynamic clearance had high thrombotic potential. For HeartMate II, regions of high hemolysis risk and bleeding probability were found in the near-wall region of the straightener, the blade tip clearance and the diffuser domain. The corners of the inlet and outlet pipe and the straightener and diffuser regions had high thrombotic potential.
The risk of hemolysis, bleeding and thrombosis for these five VADs, in increasing order, was Impella 5.0, UltraMag, CHVAD, HVAD, and HeartMate II. Flow losses caused by the rotor mechanical movement, chaotic flow and narrow clearances increase the blood damage for all these VADs. The multi-indicator analysis can comprehensively evaluate the VAD performance with improved assessment accuracy of CFD.