A permanent left ventricular-assist device: in vivo testing

Abstract

An electric-motor-driven left-ventricular-assist device has been under in vivo evaluation since 1984. The device has been implanted in twelve calves, the longest surviving 174 days and the average survival being 64 days. The device contains a brushless DC motor and a rollerscrew mechanism. The mechanism produces rectilinear motion of a pusher plate, which pushes on the segmented polyurethane blood sac. In three of the twelve animal experiments, a transcutaneous energy transmission system was utilized to transmit energy across the intact skin. The reasons for termination of the experiments were a variety of factors, including cracked polysulfone blood pump cases, inlet obstruction, a broken cable, and rust on components that were manufactured of an improper material. Thromboembolic complications were seen in only one of twelve animals. Average survival times increased from an annual average of 25 days in 1984 to over 74 days in 1987.