Thoratec Corporation (NASDAQ: THOR) is engaged in the research, development, manufacturing and marketing of medical devices for circulatory support and vascular graft applications. The Thoratec™ VAD System is the only ventricular assist device that is approved for use both as a bridge to transplant and for recovery from open-heart surgery. The company is also a leader in the research, development and manufacture of implantable left ventricular assist systems (LVAS). Its air-driven and electric HeartMate™ heart assist devices, which are approved for sale in the U.S., Europe and Canada, are implanted alongside the natural heart and take over the pumping function of the left ventricle for patients whose hearts are too damaged or diseased to produce adequate blood flow. In addition, the company’s Vectra™ vascular access graft, which is used in patients undergoing hemodialysis, is approved for sale in the U.S., Europe and Japan and a number of other foreign countries.