Itkin George P, Bychnev Alexander S, Kuleshov Arkady P, Drobyshev Alexander A
Laboratory of Biotechnical Systems, Federal State Budgetary Institution 'Academician V.I. Shumakov Federal Research Center of Transplantology and Artificial Organs', Ministry of Health of the Russian Federation, Moscow, Russian Federation.
Int J Artif Organs. 2020 Mar;43(3):157-164. doi: 10.1177/0391398819879939. Epub 2019 Oct 11.
Continuous-flow ventricular-assist devices are widely used to support patients with advanced heart failure, because continuous-flow ventricular-assist devices are more durable, have smaller sizes and have better survival rates for patients compared to the pulsatile-flow ventricular-assist devices. Nevertheless, continuous-flow ventricular-assist devices often cause complications such as gastrointestinal bleeding, haemorrhagic stroke, and aortic insufficiency and have a negative impact on the microcirculation for both long-time implantable and short-time extracorporeal systems. The aim of this study is the evaluation of the pulsatile-flow generation method in continuous-flow ventricular-assist device without pump speed changes. The method may be used for short-time extracorporeal continuous-flow mechanical circulatory support and long-time implantable mechanical circulatory support. A shunt with a controlled adjustable valve, that clamps periodically, is connected in parallel to the continuous-flow ventricular-assist device. We compared the continuous-flow ventricular-assist device operating with and without the shunt on the mock circulation loop. The continuous-flow ventricular-assist device-shunt system was connected according to the left ventricle-aorta circuit and worked in phase with the ventricle. Heart failure was simulated on the mock circulation circuit. Rotaflow (Maquet Inc.) was used as the continuous-flow pump. Haemolysis studies of the system for generating a pulse flow were carried out at a flow rate of 5 L/min and a pressure drop of 100 mm Hg. To compare the haemodynamic efficiency, we used the aortic pulsation index , the equivalent energy pressure and the surplus haemodynamic energy. These indexes were higher in the pulsatile mode ( - 4 times, equivalent energy pressure by 7.36% and surplus haemodynamic energy - 10 times), while haemolysis was the same. The normalised index of haemolysis was 0.0015 ± 0.001. The results demonstrate the efficiency of the pulsatile-flow generation method for continuous-flow ventricular-assist devices without impeller rotation rate changes.
连续流心室辅助装置被广泛用于支持晚期心力衰竭患者，因为与搏动流心室辅助装置相比，连续流心室辅助装置更耐用、尺寸更小且患者生存率更高。然而，连续流心室辅助装置常引发诸如胃肠道出血、出血性中风和主动脉瓣关闭不全等并发症，并且对长期植入式和短期体外系统的微循环均有负面影响。本研究的目的是评估在不改变泵速的情况下，连续流心室辅助装置中的搏动流产生方法。该方法可用于短期体外连续流机械循环支持和长期植入式机械循环支持。一个带有可控调节阀且能周期性夹闭的分流器与连续流心室辅助装置并联连接。我们在模拟循环回路上比较了有分流器和无分流器运行的连续流心室辅助装置。连续流心室辅助装置 - 分流器系统按照左心室 - 主动脉回路连接，并与心室同步工作。在模拟循环回路上模拟心力衰竭。使用Rotaflow（马奎特公司）作为连续流泵。在流速为5升/分钟和压降为100毫米汞柱的条件下，对产生脉冲流的系统进行溶血研究。为比较血流动力学效率，我们使用了主动脉搏动指数、等效能量压力和剩余血流动力学能量。这些指标在搏动模式下更高（主动脉搏动指数高4倍，等效能量压力高7.36%，剩余血流动力学能量高10倍），而溶血情况相同。溶血的标准化指数为0.0015±0.001。结果证明了在不改变叶轮转速的情况下，连续流心室辅助装置的搏动流产生方法的有效性。
