可植入式心室辅助装置动物模型的建立

目的探讨建立可植入式心室辅助装置研究的实验动物模型。方法选取体质量120-180 kg小公牛7只,常规全麻后左侧第4肋间开胸,建立体外循环,体外循环辅助下诱颤后,植入自主研发的国产可植入式心室辅助装置（DIVAD,domestic-made implantable ventricular assist device）,DIVAD机械性能参数接近国际同类产品,泵尺寸29.5mm×72 mm,重量158 g,体外转速可达9000 r/min,流量可达8 L/min,整合流量计,并可通过体外控制器监测控制。DIVAD连接左室及降主动脉,转速3500-8000 r/min左右,行左室辅助。术后撤除体外循环,持续监测动物生命体征及DIVAD运转情况。肝素静滴维持ACT在正常值1.5-2倍之间。结果7只小牛术后全部复跳,均能成功撤离体外循环辅助,最长存活时间超过93 h,最短存活时间0.5 h,平均存活时间20.28 h。结论小牛可以作为DIVAD研究的合适动物模型,其围手术期处理有相应特点,小牛DIVAD实验模型的建立对于进一步研究改进DIVAD有重要作用。

Establishment of an Animal Model for Implantable Ventricular Assist Device

Objective To establish an animal model for implantable ventricular assist device. Methods Seven male calves, body weight 120 to 180 kg, were anesthetized and underwent surgical implantation through a left thoracotomy at the 4th intercostal space. The domestic-made implantable ventricular assist device (DIVAD) was implanted after cardiopulmonary bypass and induction of ventricular fibrillation. The major indexes of mechanical properties of the DIVAD are similar to those of imported devices. The DIVAD was 29.5 mm × 72 mm, with a total weight of 158 g. The maximal pump speed was 9000 rpm and the maximal pump flow was 8 L/min in in vitro experiment. A flow meter was incorporated into the pump. The DIVAD was constructed with an external controller, and the pump can be monitored and adjusted through it. The inflow cannula was positioned into the left ventricle and the outflow cannula was sutured to the descending aorta. The pump was run at 3,500 to 8,000 rpm. The cardiopulmonary bypass was weaned. The pump output and animal condition was continuously monitored. Heparin was administered to maintain the activated clotting time at 1.5 to 2 times its baseline value. Results All the seven calves weaned from cardiopulmonary bypass. The mean survival time is 20.28 hours with a range from 0.5 to more than 93 hours. Conclusion Calf is the right animal model for NIVAD implantation and there are some characteristics in its perioperative treatment. The establishment of this animal model may play important role for further improvement of NIVAD.