In vitro pulsatility analysis of axial-flow and centrifugal-flow left ventricular assist devices.
In vitro pulsatility analysis of axial-flow and centrifugal-flow left ventricular assist devices.
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DOI：
10.1115/1.4023525
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
J. R. Stanfield;C. Selzman
中科院分区：
文献类型：
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作者：
J. R. Stanfield;C. Selzman
最近，连续流心室辅助装置（CF-VAD）已经取代了较旧的脉动流泵，用于治疗晚期心力衰竭患者。尽管新一代器械的结果很好，但长期丧失脉动性的影响仍然未知。本研究的目的是比较轴流式和离心式连续流泵在不同生理条件下固有地改变脉动性的能力。四个VAD，两个轴向和两个离心流，进行了评价模拟循环流系统。每个VAD在三种假设的心脏条件下以恒定的叶轮速度运行：血压正常、高血压和水肿。在每种条件下比较每种器械的脉动指数（PI）。旋流装置比轴流泵具有更高的PI。在正常张力下，轴向组和离心组的血流PI分别为0.98 ± 0.03和1.50 ± 0.02（p < 0.01）。在高血压下，轴流式和离心泵的流量PI分别为1.90 ± 0.16和4.21 ± 0.29（p = 0.01）。在低血压下，轴向组和离心组的PI分别为0.73 ± 0.02和0.78 ± 0.02（p = 0.13）。当与我们的模拟心室并联连接时，所有测试的CF-VAD都能够保持一定的脉动流。从PI的基础上得出离心式流量装置在试验条件下性能优于轴流泵的结论。
Recently, continuous-flow ventricular assist devices (CF-VADs) have supplanted older, pulsatile-flow pumps, for treating patients with advanced heart failure. Despite the excellent results of the newer generation devices, the effects of long-term loss of pulsatility remain unknown. The aim of this study is to compare the ability of both axial and centrifugal continuous-flow pumps to intrinsically modify pulsatility when placed under physiologically diverse conditions. Four VADs, two axial- and two centrifugal-flow, were evaluated on a mock circulatory flow system. Each VAD was operated at a constant impeller speed over three hypothetical cardiac conditions: normo-tensive, hypertensive, and hypotensive. Pulsatility index (PI) was compared for each device under each condition. Centrifugal-flow devices had a higher PI than that of axial-flow pumps. Under normo-tension, flow PI was 0.98 ± 0.03 and 1.50 ± 0.02 for the axial and centrifugal groups, respectively (p < 0.01). Under hypertension, flow PI was 1.90 ± 0.16 and 4.21 ± 0.29 for the axial and centrifugal pumps, respectively (p = 0.01). Under hypotension, PI was 0.73 ± 0.02 and 0.78 ± 0.02 for the axial and centrifugal groups, respectively (p = 0.13). All tested CF-VADs were capable of maintaining some pulsatile-flow when connected in parallel with our mock ventricle. We conclude that centrifugal-flow devices outperform the axial pumps from the basis of PI under tested conditions.