Small Diameter, High Output, Durable Transapical LVAD

Perfusion Solutions, Inc., South Euclid OH

Investigators

Abstract

? DESCRIPTION (provided by applicant): Ventricular assist devices (VAD's) clearly have a role in cardiac medicine; how to precisely define that role is still subject to research and debate, considering the possibilities of destination therapy, bridge to transplant, bridge to recovery, bridge to definitive therapy and possibly other variants one might specify. Certain VAD features are emerging as required: sufficient output to truly make a difference to the patient, reliability through the period of use, however long that might turn out to be after support is instituted; ease of use; and minimal morbidities associated with use. Major medical problems associated with VAD employment have included infection, bleeding and thromboembolic events. Cardiopulmonary bypass, significant incisions to implant VAD's and extensive tissue/organ displacement further weaken already very ill patients, provide pathways for bacterial and fungal ingress, and result in adhesions impeding later surgeries. Serous fluid-filled pockets around pumps are bacterial breeding grounds, and extensive foreign body surfaces are opportunities for adhesive, antibiotic resisting bacterial colonies to form. Shear stresses can shorten red cell life and disturb both platelet and leukocyte function. Thrombosis on the foreign surfaces of the pump can form and later embolize, and/or systemic coagulation pathologies occur. Aggressive pump anticoagulation protocols limit a clinician's ability to respond to other patient issues. Perfusion Solutions, Inc. (PSI) technology addresses these issues. Utilizing passive magnetic bearings, durability over 4 years has been demonstrated. Flows of 5 LPM at significant pressure differential are possible. These bearings enable much larger, lower shear gaps than hydrodynamic bearings, and an earlier prototype of this technology, using the same motor and bearings, demonstrated low bench hemolysis and baseline free hemoglobin in 30-day lamb implants. Based on the discussions of clinical needs and the characteristics of the PSI technology with thought leaders in the mechanical circulatory support field, we will next develop this for minimally invasive, transapical implant. This concept is not new, but our pump holds particular virtues for this implementation. A polymer outflow sleeve will carry flow through the aortic valve. There are two feasibility issues during phase I; (1) Does the apical pump prototype have hydraulic and hemolysis performance matching the characteristics of the existing PSI prototypes; and, (2) Will two 14-day calf implants match the bench hydraulic characteristics, show hematology and biochemistry results in the normal range, have no thromboembolic events, and at autopsy show no short term significant damage to the valve leaflets, the papillary muscles, the chordae, or other cardiac structures? The performance to be matched will be described. During phase II, new pump prototypes will be built and used for 30, 60 and 90 day studies extending the in vivo demonstration beyond the phase I data, while the Phase I pumps will join other PSI pump prototypes on long term endurance testing.