Development of implantable right ventricular assist device

Implantable ventricular assist devices (VADs) are indicated for long waiting periods before transplantation and also as a destination therapy. Meanwhile, right ventricular failure (RVF) is one of the four major complications observed in patients after left VAD (LVAD) implantation, with an incidence of approximately 20%. Preoperative prediction of the complication remains difficult, and the mortality is very high. To date, no implantable right VAD (RVAD) is available for the clinical situation. The possibility of realizing an implantable RVAD with Gyro centrifugal pump (PI-710 pump) was investigated. Eleven chronic animal experiments with LVAD and RVAD implantation were performed. Right heart bypass was established between right outflow and pulmonary trunk, and the pump was implanted in the preperitoneal space. The anatomic fit was good. The mean term of the experiments was 59 days, with excellent pump performance. Stable pulmonary hemodynamics and respiratory function were maintained during all of the experimental terms. No specific abnormal histologic findings of the lung were confirmed; however, tunica media hypertrophy was recognized in some cases. The PI-710 pump is feasible as a clinically implantable RVAD, but further study of histologic and pulmonary vascular changes after RVAD implantation is needed.