ABSTRACT
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.