Journal of Artificial Organs

, Volume 14, Issue 1, pp 74–79

A novel counterpulse drive mode of continuous-flow left ventricular assist devices can minimize intracircuit backward flow during pump weaning

Authors

    • Department of Artificial OrganNational Cardiovascular Center Research Institute
    • Department of Cardiothoracic SurgeryThe University of Tokyo
  • Takashi Nishimura
    • Department of Therapeutic Strategy for Heart FailureThe University of Tokyo
  • Yoshiaki Takewa
    • Department of Artificial OrganNational Cardiovascular Center Research Institute
  • Daisuke Ogawa
    • Sun Medical Technology Research Corporation
  • Kenji Yamazaki
    • Department of Cardiovascular SurgeryTokyo Women’s Medical University
  • Koichi Kashiwa
    • Department of Medical EngineeringThe University of Tokyo Hospital
  • Shunei Kyo
    • Department of Therapeutic Strategy for Heart FailureThe University of Tokyo
  • Minoru Ono
    • Department of Cardiothoracic SurgeryThe University of Tokyo
  • Yoshiyuki Taenaka
    • Department of Artificial OrganNational Cardiovascular Center Research Institute
  • Eisuke Tatsumi
    • Department of Artificial OrganNational Cardiovascular Center Research Institute
Brief Communication

DOI: 10.1007/s10047-010-0544-6

Cite this article as:
Ando, M., Nishimura, T., Takewa, Y. et al. J Artif Organs (2011) 14: 74. doi:10.1007/s10047-010-0544-6

Abstract

Recent developments in adjunct therapeutic options for end-stage heart failure have enabled us to remove implanted left ventricular assist devices (LVADs) from more patients than before. However, a safe and proper protocol for pump-off trials is yet to be established, because diastolic backward flow in a pump circuit turns up when it is driven at low-flow conditions. We have developed a novel drive mode of centrifugal pumps that can change its rotational speed in synchronization with the cardiac cycle of the native heart. The purpose of this study was to test-drive this novel system of a centrifugal pump in a mock circulation and to evaluate the effect of the counterpulse mode, which increases pump speed just in diastole, on the amount of this nonphysiological intracircuit retrograde flow. A rotary pump (EVAHEART, Sun Medical Technology Research Corporation) was connected to the mock circulation by left ventricular uptake and ascending aortic return. We drove it in the following four conditions: (A) continuous mode at 1500 rpm, (B) counterpulse mode (systolic 1500 rpm, diastolic 2500 rpm), (C) continuous mode at 2000 rpm, and (D) counterpulse mode (systolic 2000 rpm, diastolic 2500 rpm). Data concerning the rotation speed, pump flow, left ventricular pressure, aortic pressure, and pressure head (i.e., aortic pressure-left ventricular pressure) in each condition were collected. After data collection, we analyzed pump flow, and calculated its forward and backward flow. Counterpulse mode decreased the amounts of pump backward flow compared with the continuous mode [mean backward flow, −4, −1, −0.5, 0 l/min, in (A), (B), (C), and (D) conditions, respectively]. The actual amounts of mean backward flow can be different from those in clinical situations; however, this novel drive mode for rotary pumps can relatively decrease pump backward flow during pump weaning and can be beneficial for safe and proper pump-off trials. Further investigations in in vivo settings are currently ongoing.

Keywords

Left ventricular assist deviceBridge to recoveryMock circulation

Copyright information

© The Japanese Society for Artificial Organs 2011