In vitro hemolysis test of a novel left ventricular assist device

    XU Xueª²Zeng, YI Dingª²Hua, LIU Jinª²Cheng, YU Shiª²Qiang, CHEN Wenª²Sheng, YANG Jian, DUAN Weiª²Xun

    Centre of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To observe the hemolysis changes in our selfª²made left ventricular assist device in an in vitro circulation system and to investigate the effects of the flow of fluid, and the frequencies, the pressure and the systolic percentage of the device on erythrocytes. METHODS: Fresh blood samples were obtained from healthy dogs and the activated clotting time (ACT) was maintained over 450 s with heparitin. Blood samples were infused in vitro circulation system equipped with a left ventricular assist pump, and the changes of plasmaª²free hemoglobin(FHb)and fibrinogen(Fib)with different frequency, pressure and systolic percentage were observed. RESULTS: With the same flow of fluid, the higher the pressure, the higher the level of FHb and the lower the level of Fib. With the same pressure and the range of systolic time percentage from 0.25 to 0.45, relatively lower level of FHb and higher level of Fib were observed when systolic time percentage was 0.38. With the same frequency, pressure or systolic time percentage, the higher the flow volume, the higher level of FHb and the lower level of Fib. CONCLUSION: With the same flow of fluid, the pressure is positively correlated to the severity of the erythrocyte damage. The lowest efficient pressure and the systolic time percentage of 0.38 cause the least damage to erythrocytes. ......