轴向磁力卸载微型心脏轴流泵的动物实验

A hemodynamic and hemolysis study of the axial pump with hydrodynamic-magnetically levitated impeller in swine

目的 使用自主知识产权轴向磁力卸载微型植入式心脏轴流泵进行动物实验,研究轴流泵的血流动力学表现、心室去负荷效果和血液相容性.方法 实验用猪5只,体质量（40.0±5.2）kg.全麻后于左侧第5肋间开胸,植入辅助泵,泵入口引流管经心尖插入左心室,出口用人工血管与降主动脉行端侧吻合,留置左心室测压管.结果 辅助泵完全植入动物胸腔内,手术成功率100％.手术后5只实验猪均存活1周以上.辅助泵的转速与辅助效果呈正相关性.平均心室收缩压（131.6 ±28.0）mmHg（1 mmHg =0.133 kPa）,辅助时左心室舒张末期压力降低,心室内平均压随之减低.外周血流动力学稳定,辅助前、后外周循环血压无明显差异.术后1周内实验猪尿量稳定.实验猪血浆中游离血红蛋白在手术日轻微升高,术后第1天至1周逐渐恢复至术前水平.华法林3 mg/天口服抗凝,INR值维持在2.0～2.5,标本检查未发现泵内血栓形成.结论 自主知识产权轴向磁力卸载微型植入式心脏轴流泵应用于实验猪的血流动力学稳定,心脏压力去负荷效果良好,能维持良好的外周循环灌注,且具良好的血液相容性.

Objective To explore the in-vivo hemodynamic and hemolysis effect of a newly designed axial continuousflow ventricular assist device（VAD） in swine.Methods Under general anesthesia,each of 5 swine [weight （40.0 ± 5.2）kg] was implanted with the axial continuous-flow VAD into the apex of left heart ventricle,and the outflow graft was anastomosised to descending aorta.Results All of the axial continuous-flow VAD were implanted successfully with post-operative survival rate 100%.All 5 animals survived over one week.There was a positive correlation between pump speed and assistance effect.The mean left ventricular systolic pressure was （131.6 ± 28.0） mmHg（1 mmHg =0.133 kPa）.While the axial continuous-flow VAD was working,left ventricular end diastolic pressure decreased,along with mean intraventricular pressure declined.Peripheral hemodynamics was stable and peripheral blood pressure was not remarkably different from the pressure preoperation.Daily urine volume was in normal range within 1 week post operation.Free hemoglobin in plasma was slightly elevated on the surgery day,and gradually dropped to normal level within 1 week.International Normalized Ratio（INR） was maintained between 2.0-2.5 with oral adminiatration of warfarin of 3 mg/day.There was no thrombosis existing in VAD at autopsy.Conclusion The application of the axial pump with hydrodynamic-magnetically levitated impeller in animal experiment can provide stable hemodynamics,advanced heart unloaded effect,favorable peripheral perfusion,and blood compatibility is satisfactory.