Giridharan Guruprasad A, Koenig Steven C, Soucy Kevin G, Choi Young, Pirbodaghi Tohid, Bartoli Carlo R, Monreal Gretel, Sobieski Michael A, Schumer Erin, Cheng Allen, Slaughter Mark S
From the *Department of Bioengineering, Cardiovascular Innovation Institute, University of Louisville, Louisville, Kentucky 40292; †Department of Cardiovascular and Thoracic Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, Kentucky 40202; ‡Eidgenössische Technische Hochschule Hönggerberg, Zürich, Switzerland; and §Division of Cardiovascular Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104.
ASAIO J. 2015 May-Jun;61(3):282-91. doi: 10.1097/MAT.0000000000000200.
In the event of left ventricular assist device (LVAD) failure, we hypothesized that rotary blood pumps will experience significant retrograde flow and induce adverse physiologic responses. Catastrophic LVAD failure was investigated in computer simulation with pulsatile, axial, and centrifugal LVAD, mock flow loop with pulsatile (PVAD) and centrifugal (ROTAFLOW), and healthy and chronic ischemic heart failure bovine models with pulsatile (PVAD), axial (HeartMate II), and centrifugal (HVAD) pumps. Simulated conditions were LVAD "off" with outflow graft clamped (baseline), LVAD "off" with outflow graft unclamped (LVAD failure), and LVAD "on" (5 L/min). Hemodynamics (aortic and ventricular blood pressures, LVAD flow, and left ventricular volume), echocardiography (cardiac volumes), and end-organ perfusion (regional blood flow microspheres) were measured and analyzed. Retrograde flow was observed with axial and centrifugal rotary pumps during LVAD failure in computer simulation (axial = -3.4 L/min, centrifugal = -2.8 L/min), mock circulation (pulsatile = -0.1 L/min, centrifugal = -2.7 L/min), healthy (pulsatile = -1.2 ± 0.3 L/min, axial = -2.2 ± 0.2 L/min, centrifugal = -1.9 ± 0.3 L/min), and ischemic heart failure (centrifugal = 2.2 ± 0.7 L/min) bovine models for all test conditions (p < 0.05). Differences between axial and centrifugal LVAD were statistically indiscernible. Retrograde flow increased ventricular end-systolic and end-diastolic volumes and workload, and decreased myocardial and end-organ perfusion during LVAD failure compared with baseline, LVAD support, and pulsatile LVAD failure.
在左心室辅助装置（LVAD）发生故障的情况下，我们推测旋转血泵会出现显著的逆向血流，并引发不良的生理反应。我们通过计算机模拟、模拟血流回路以及健康和慢性缺血性心力衰竭牛模型，对LVAD灾难性故障进行了研究。计算机模拟中使用了搏动性、轴流和离心式LVAD；模拟血流回路中使用了搏动性（PVAD）和离心式（ROTAFLOW）血泵；在健康和慢性缺血性心力衰竭牛模型中分别使用了搏动性（PVAD）、轴流（HeartMate II）和离心式（HVAD）血泵。模拟条件包括：流出道移植物夹闭时LVAD“关闭”（基线）、流出道移植物未夹闭时LVAD“关闭”（LVAD故障）以及LVAD“开启”（5升/分钟）。测量并分析了血流动力学指标（主动脉和心室血压、LVAD流量以及左心室容积）、超声心动图指标（心脏容积）和终末器官灌注指标（局部血流微球）。在计算机模拟（轴流=-3.4升/分钟，离心=-2.8升/分钟）、模拟循环（搏动性=-0.1升/分钟，离心=-2.7升/分钟）、健康（搏动性=-1.2±0.3升/分钟，轴流=-2.2±0.2升/分钟，离心=-1.9±0.3升/分钟）以及缺血性心力衰竭（离心=2.2±0.7升/分钟）牛模型中，所有测试条件下均观察到LVAD故障期间轴流和离心旋转泵出现逆向血流（p<0.05）。轴流和离心式LVAD之间的差异在统计学上无明显区别。与基线、LVAD支持以及搏动性LVAD故障相比，LVAD故障期间逆向血流增加了心室收缩末期和舒张末期容积以及工作量，并减少了心肌和终末器官灌注。
