Selmi Matteo, Chiu Wei-Che, Chivukula Venkat Keshav, Melisurgo Giulio, Beckman Jennifer Ann, Mahr Claudius, Aliseda Alberto, Votta Emiliano, Redaelli Alberto, Slepian Marvin J, Bluestein Danny, Pappalardo Federico, Consolo Filippo
1 Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy.
2 Department of Surgery, Division of Cardiac Surgery, Università di Verona, Verona, Italy.
Int J Artif Organs. 2019 Mar;42(3):113-124. doi: 10.1177/0391398818806162. Epub 2018 Oct 24.
: Despite significant technical advancements in the design and manufacture of Left Ventricular Assist Devices, post-implant thrombotic and thromboembolic complications continue to affect long-term outcomes. Previous efforts, aimed at optimizing pump design as a means of reducing supraphysiologic shear stresses generated within the pump and associated prothrombotic shear-mediated platelet injury, have only partially altered the device hemocompatibility.
: We examined hemodynamic mechanisms that synergize with hypershear within the pump to contribute to the thrombogenic potential of the overall Left Ventricular Assist Device system.
: Numerical simulations of blood flow in differing regions of the Left Ventricular Assist Device system, that is the diseased native left ventricle, the pump inflow cannula, the impeller, the outflow graft and the anastomosed downstream aorta, reveal that prothrombotic hemodynamic conditions might occur at these specific sites. Furthermore, we show that beyond hypershear, additional hemodynamic abnormalities exist within the pump, which may elicit platelet activation, such as recirculation zones and stagnant platelet trajectories. We also provide evidences that particular Left Ventricular Assist Device implantation configurations and specific post-implant patient management strategies, such as those allowing aortic valve opening, are more hemodynamically favorable and reduce the thrombotic risk.
: We extend the perspective of pump thrombosis secondary to the supraphysiologic shear stress environment of the pump to one of Left Ventricular Assist Device system thrombosis, raising the importance of comprehensive characterization of the different prothrombotic risk factors of the total system as the target to achieve enhanced hemocompatibility and improved clinical outcomes.
尽管左心室辅助装置的设计和制造在技术上取得了重大进展，但植入后的血栓形成和血栓栓塞并发症仍然影响着长期预后。以往旨在优化泵的设计以减少泵内产生的超生理剪切应力及相关的促血栓形成的剪切介导的血小板损伤的努力，仅部分改变了装置的血液相容性。
我们研究了与泵内高剪切协同作用以促成整个左心室辅助装置系统血栓形成潜力的血流动力学机制。
对左心室辅助装置系统不同区域（即患病的天然左心室、泵流入插管、叶轮、流出移植物和吻合的下游主动脉）的血流进行数值模拟，结果显示在这些特定部位可能出现促血栓形成的血流动力学状况。此外，我们表明除了高剪切之外，泵内还存在其他血流动力学异常，这可能引发血小板活化，例如再循环区域和停滞的血小板轨迹。我们还提供证据表明，特定的左心室辅助装置植入配置和特定的植入后患者管理策略，如那些允许主动脉瓣开放的策略，在血流动力学上更有利，并降低了血栓形成风险。
我们将泵的超生理剪切应力环境继发的泵血栓形成观点扩展到左心室辅助装置系统血栓形成观点，提高了全面表征整个系统不同促血栓形成危险因素的重要性，将其作为实现增强血液相容性和改善临床结果的目标。
