Establishment of an Animal Model for Implantable Ventricular Assist Device / 中国实验动物学报

ABSTRACT

@#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.