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The DexAide right ventricular assist device (RVAD) is an implantable centrifugal pump modified from the CorAide left ventricular assist device. As previously published, in vitro performance testing of the DexAide RVAD has met design criteria, and the nominal operating condition of 4 l/min and 20 mm Hg pressure rise was achieved at 2,000 rpm, with a power consumption of 1.9 watts. In vivo studies in 14 calves have demonstrated acceptable hemodynamic characteristics. The calf inflow cannula design is still evolving to minimize depositions on the cannula observed in most experiments. Fitting studies were performed in 5 cadavers and 2 patients to reconfigure the cannulae for use in humans. The design and development of external electronics have been completed for the stand-alone RVAD system, and verification tests are under way in preparation for preclinical tests. Work on the external electronics design for the biventricular assist system is ongoing. In conclusion, the initial in vitro and in vivo studies have demonstrated acceptable hemodynamic characteristics of the DexAide RVAD. The design and development of the external electronic components for the stand-alone RVAD system have been completed. The calf inflow cannula is being redesigned, and chronic in vivo tests are under way.

The Cleveland Clinic Foundation CPB/ECMO Initiative Forward Casualty Management System is an economical, compact, transportable, disposable system designed to permit a rapid expansion of trauma management services requiring cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) pulmonary support. The system, composed of a rotary blood pump, a pump motor driver, and an electronic control console as the blood pumping subsystem, also includes commonly used compatible commercial oxygenators, venous reservoirs, and cannulae. In vitro durability testing accumulated over 100 hours without failure. In vivo reliability was tested in 10 calves under general anesthesia during 6 hours of CPB and ECMO under full heparinization at nominal operating conditions of 4-5 l/min and 2-4 l/min blood flow respectively, and mean arterial pressures between 65 and 100 mm Hg. A mean time to failure of 57 hours was reached during the animal series. Results of these test series demonstrated that this system has the capability to reliably operate during a 6-hour conventional CPB or ECMO procedure, while providing flexibility and ease of use for the operator.

Despite the increasing use of left ventricular assist devices for patients with end-stage congestive heart failure, no implantable, centrifugal right ventricular assist devices (RVADs) are available for those patients with significant right ventricular failure. The DexAide RVAD was developed to provide an implantable RVAD option to surgeons. The aim of this study was to evaluate pump performance in an acute in vivo model. The DexAide RVAD, developed as a modified CorAide left ventricular assist device, was implanted between the right ventricle and the pulmonary artery in four healthy calves. Pump speed was varied from 1800 rpm to 3600 rpm. RVAD performance was analyzed acutely at baseline and under conditions of low circulating volume, high contractility, high pulmonary arterial pressure, vasodilation, and low contractility. Pump flow was well maintained even under conditions of high pulmonary arterial pressure and vasodilation, with the exception of low circulating volume. Under all conditions, pulmonary arterial pressures were not affected by changing pump speed. The DexAide RVAD demonstrated acceptable hemodynamic characteristics for use as an implantable RVAD in the initial acute studies. Further studies are ongoing to examine the biocompatibility of the pump under chronic conditions.

The purpose of this program is to design, develop, and clinically evaluate a new, implantable right ventricular assist device (RVAD) that can be used as a component of an implantable biventricular assist device for patients with severe biventricular heart failure. The initial phase of this program resulted in a prototype RVAD, named DexAide, a modified version of the CorAide left ventricular assist device. In vitro testing was performed in a stand-alone circuit and in a true RVAD mode to evaluate pump performance. Pump flow and power were measured under various afterload and pump speed conditions. The pump performance requirements of 2 to 6 l/min and a pressure rise of 20 to 60 mm Hg were successfully met with pump speeds between 1,800 and 3,200 rpm. The nominal design point of 4 l/min and 40 mm Hg pressure rise was achieved at 2,450 +/- 70 rpm with a power consumption of 3.0 +/- 0.2 W. The initial in vitro testing met the design criteria for the new DexAide RVAD. Initial in vivo testing is under way, which will be followed by preclinical readiness testing and a pilot clinical trial in this 5-year program.