Design Rationale and Preclinical Evaluation of the HeartMate 3 Left Ventricular Assist System for Hemocompatibility
Design Rationale and Preclinical Evaluation of the HeartMate 3 Left Ventricular Assist System for Hemocompatibility
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DOI：
10.1097/mat.0000000000000388
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发表时间：
2016-07-01
期刊：
影响因子：
4.2
通讯作者：
Burke, Edward
中科院分区：
文献类型：
--
作者：
Bourque, Kevin;Cotter, Christopher;Burke, Edward
HeartMate 3（HM 3）左心室辅助装置（LVAD）旨在支持晚期心力衰竭患者。该离心泵具有磁悬浮转子、人工脉冲、纹理化血液接触表面、优化的流体动力学、大血流间隙和低剪切应力。进行临床前试验以评估血液相容性。采用计算流体动力学（CFD）模型指导设计，实现低剪切应力和充分清洗。对6台泵进行了溶血试验。将血浆游离血红蛋白（PfHb）和改良溶血指数（MIH）与HeartMate II（HM II）进行比较。计算流体动力学（CFD）显示二次流路径停留时间在27 - 798 min之间，与主流停留时间在118 - 587 min之间相当;在泵体积内，HM 3与HM II剪切应力暴露在150 Pa以上分别为3.3与11 mm（3），在表面上分别为134与604 mm（2）。在2、5和10 L/min的体外溶血试验中，试验开始后6小时的平均pfHb为58、74和157 mg/dl，而HM II为112、123和353 mg/dl。在2、5和10 L/min时，平均MIH的HM 3/HM II比值分别为0.29、0.36和0.22。对8个60天牛植入物进行了试验，平均流速为5.6 - 6.4 L/min，无器械失效、血栓形成或溶血。结果支持将HM 3推进临床试验。
The HeartMate 3 (HM3) left ventricular assist device (LVAD) is designed to support advanced heart failure patients. This centrifugal flow pump has a magnetically levitated rotor, artificial pulse, textured blood-contacting surfaces, optimized fluid dynamics, large blood-flow gaps, and low shear stress. Preclinical tests were conducted to assess hemocompatibility. A computational fluid dynamics (CFD) model guided design for low shear stress and sufficient washing. Hemolysis testing was conducted on six pumps. Plasma-free hemoglobin (PfHb) and modified index of hemolysis (MIH) were compared with HeartMate II (HMII). CFD showed secondary flow path residence times between 27 and 798 min, comparable with main flow residence times between 118 and 587 min; HM3 vs. HMII shear stress exposure above 150 Pa was 3.3 vs. 11 mm(3) within the pump volume and 134 vs. 604 mm(2) on surfaces. In in vitro hemolysis tests at 2, 5, and 10 L/min, average pfHb 6 hours after test initiation was 58, 74, and 157 mg/dl, compared with 112, 123, and 353 mg/dl for HMII. The HM3/HMII ratio of average MIH at 2, 5, and 10 L/min was 0.29, 0.36, and 0.22. Eight 60 day bovine implants were tested with average flow rates from 5.6 to 6.4 L/min with no device failures, thrombosis, or hemolysis. Results support advancing HM3 to clinical trials.