Development of a totally implantable, electrically actuated left ventricular assist system

A totally implantable left ventricular assist system has been under development at Stanford since 1972. The system fabricated for clinical use employs a highly efficient, electrically powered solenoid drive system coupled to a dual pusher-plate blood pump with xenograft inflow and outflow valves. The system is of suitable size for implantation either within the anterior abdominal wall or anterolateral within the peritoneal cavity, with pump inflow and outflow cannulas from the left ventricular apex and to the supraceliac aorta, respectively. Thus, the system is well suited for short-term cardiac support after cardiac surgical procedures, being easily explantable due to its superficial location. In addition, long-term support, with the possibility of subsequent cardiac transplantation, is feasible when intrinsic myocardial dysfunction is irreversible, in contrast to existing pneumatically powered systems which require percutaneous drive-lines and compressed air sources. Although the integrated clinical left ventricular assist system described has not been extensively tested in vivo, more than 6,500 hours of operation in calves has been accumulated with a related system; the maximum duration of continuous left ventricular assist using this system in vivo has been 129 days, the longest reported successful operation of such an electrically driven system. These experimental studies have demonstrated the capability of the device to provide total systemic circulatory support for a prolonged period in the context of a severely failing left ventricle.