Background. The AB-180 circulatory support system is a small, durable, efficient centrifugal pump with low thrombogenic potential. The device was designed to provide a fully implantable, left ventricular assist system for short-term support to address the issues of systemic anticoagulation, thrombus formation, infection, and cost. Methods. Extensive bench and animal studies were performed to validate the mechanical integrity of the device and its functionality as an implant. Results. These studies demonstrated anticoagulation requirements, established operating guidelines, incorporated safety systems, and demonstrated safety and efficacy. Conclusions. The AB-180 fulfills the stated goals on initial evaluation. A phase I human trial is underway. (C) 1999 by The Society of Thoracic Surgeons.