A versatile intracorporeal ventricular assist device based on the ThoratecVAD system

Background. As patients are supported for longer durations with paracorpore al Thoratec left ventricular and biventricular assist devices (longest dura tions: 515 and 457 days, respectively), there is a need for implantable opt ions. Methods. We are developing a small, simple, and versatile intracorporeal ve ntricular assist device (IVAD) for left, right, or biventricular support as an alternative to the large, implantable, pulsatile left ventricular assis t device (LVAD) systems available today. The new device is based on the Tho ratec paracorporeal VAD that has been used in more than 1,400 patients weig hing from 17 to 144 kg and for durations exceeding 1 year including patient discharge (using the portable driver). Results. The IVAD has the same blood flow path and Thoralon polyurethane bl ood pumping sac as the paracorporeal VAD, but the housing is a smooth conto ured, polished titanium alloy. The IVAD has a new sensor to detect when the pump is full and empty, and is controlled with the Thoratec TI,C-II portab le VAD driver, which is a small, briefcase-sized, battery-powered, pneumati c control unit. A small flexible (9 mm OD) percutaneous pneumatic driveline for each VAD is tunneled out of the body from the LVAD or right VAD in a p re- or intraperitoneal position. Small size and simplicity are the major ad vantages of the new device. The IVAD weight (339 g) and implanted volume (2 52 mt) are approximately one-half that of the current implantable pulsatile electromechanical LVAD systems. Conclusions. The small size of the IVAD should not only allow support of a large range of patient sizes and body habitus, but also provide options for implantable left, right, or biventricular support. By implanting only the mechanically simple blood pump, the more complex control unit is external, where it can be serviced and replaced without surgery. The IVAD with the po rtable driver will be a viable alternative to large implanted electromechan ical systems and should address a larger segment of the physically diverse patient population. (C) 2001 by The Society of Thoracic Surgeons.