LVAD use is increasing for both bridge and destination applications, but the need for right ventricular assist is apparent, even in patients selected to avoid this complication. These patients usually receive a temporary right ventricular assist device (RVAD) with a short-lived, external pump when the need becomes apparent, although the survival rate is superior with a pre-operatively planned biventricular implant. The difficulty is a paucity of good implantable systems for RVAD use. Existing implantable LVAD pumps adapted to this use bring with them significant compromises for right sided use. Perfusion Solutions has developed a passive magnetic bearing pump (the M2F) that has been demonstrated in multiple sizes. The most extensively developed 10 mm pump is well-suited as an implanted, long-term RVAD. It is very small but produces strong flow and pressure for the pulmonary circulation. The magnetic bearing is not speed sensitive so the pump can be set to slow speed if the ventricle recovers but remain functional if there is a renewed issue with pulmonary resistance or ventricular function. The geometry is compatible with flexible implant approaches per individual case constraints. Hemolysis is extraordinarily low, perhaps due to the large, low shear magnetic bearing clearances. The pump has shown multi-year durability. The innovation of this project is the provision of the first clinical implantable RVAD which does not require major compromises to adapt to the application. The technical issues with respect to conversion of the M2F LVAD for RVAD applications are not challenging. The feasibility issue is biocompatibility as an RVAD implant. Initial feasibility will be demonstrated by two calf implants without thrombus issues.
The specific aims for phase I are: (1) design of anatomically compatible and biocompatible RVAD inflow and outflow cannulae; (2) fabrication of two M2F RVAD pumps; (3) bench performance and hemolysis testing; and (4) two, 14-day in vivo RVAD implants. During Phase II, we will build 8 more systems. The database of bench testing will be increased. Longer duration implants will be performed as BiVAD's, combining the PSI system with a commercially available LVAD as appropriate at the time of the phase II proposal and award. This will demonstrate a first clinically usable product superior to anything now available or becoming available in the near future and lead into development of a fully integrated BiVAD system utilizing the clinical experience. PSI is a Cleveland Clinic spin-off company. In this project, it is teamed with the Clinic's Kaufman Heart Failure Center and Cardiovascular Dynamics Laboratory to meet the pressing need for a satisfactory RVAD system.
Left ventricular assist devices (LVADs) have proven to be a lifesaving treatment for end stage heart failure. However, many patients are excluded from this treatment because of obviously inadequate right ventricular function, while some LVAD recipients die or have poor quality of life because their right side function proves to be poorer than expected. Today only temporary right side assist pumps are available, which is inadequate for large number as of patients. This project will demonstrate a small and effective long term implantable pump more suitable for right side use than any technology on the horizon for these patients.
