Ⅱ型轴流泵左心辅助装置的动物体内植入实验

摘要

目的:通过动物体内植入实验,观察改进后的“Ⅱ型”轴流泵的生理效果及工作特性.方法:普通家猪6只,体质量60～70 kg,全麻后于左侧第4-5肋间开胸,将“Ⅱ型”轴流泵植入动物胸腔内,泵入口引流管经心尖插入左心室腔,出口用人造血管与降主动脉行“端-侧”吻合,将心室血液转流至降主动脉.由左心房插入细导管经二尖瓣进入左心室测定心室压,经右股动脉插管入升主动脉测定主动脉压.结果:“Ⅱ型”轴流泵可完全植入动物胸腔内,平均心室收缩压为(137±23) mmHg(1 mmHg=0.133 kPa),开启轴流泵后可见心室收缩压降低,且随泵转速增加逐步下降.在转速为10 000 r/min时平均心室收缩压可降低至(32±14) mmHg,而平均动脉压仍然维持在(122±28)mmHg的正常范围,此结果显示“Ⅱ型”轴流泵可在充分降低心脏负荷的同时维持正常的外周循环.结论:“Ⅱ型”轴流泵有较好的解剖相容性和可植入性,血液动力学特性基本满足左心辅助要求.%Objective To evaluate in vivo performance and physiological effects of recently meliorated type Ⅱ axial flow pump by animal experiments.Methods Six swine,with the weights of 60-70 kg,were anesthetized intravenously and maintained with a volume-limited ventilator via a tracheotomy tube.The left chest was entered through a posterolateral thoracotomy at the fifth costal space.Then,type Ⅱ axial flow pump was placed into the thorax,bypassing the left ventricle,through an apex cut by a cannula for inflow,to the descending thoracic aorta by a side-to-end anastomosis with a artificial vessel for outflow.Two thincatheters were respectively inserted into the aortic arch via the right femoral artery for aortic pressure record and into the leftventricular via the left atrium for left ventricular pressure inspection.Results Type Ⅱ axial flow pump could be totally implanted into the thorax without difficulty.Normally,the left ventricular systolic pressure measured (137 ± 23)mmHg.Significant change in the left ventricular pressure could be induced by the start of pump.The left ventricular systolic pressure was instantly decreased with the increase of pump rotational speed,while the aortic pressure remained normal.Typically,the left ventricular systolic pressure was lowered to (32 ± 14) mmHg at the pump speed of 10 000 r/min while the aortic pressure maintained at (122 ± 28) mmHg.The results indicated that type Ⅱ axial pump could effectively unload the ventricle and sustain the normalcirculation at the same time.Conclusion Type Ⅱ axial flow pump has a good anatomic fit,and the hemodynamic feature is eligible for using as a LVAD and promises to be used in the clinical practice in near future.