The investigation of closed left heart bypass.

The present hospital mortality rate for myocardial infarction is reported as 47%, and when shock occurs it is said to be above 85% regardless of the type of therapy. Most of these patients die in left heart failure. It is obvious that present treatment of myocardial infarction is inadequate and a new approach is required. The answer appears to lie in some type of support to the heart which could adequately maintain systemic and coronary circulation, while the damaged myocardium recovers from its injury. With such assisted circulation surgical correction could be accomplished in isolated lesions and collateral circulation might develop in diffuse disease

HeartSaver VAD: A Totally Implantable Ventricular Assist Device. Results of In Vivo Studies

Currently, the most widely utilized ventricular assist devices (VADs) require percutaneous connections and are located either externally (e.g., Thoratec, Abiomed) or intra-abdominally (e.g., Novacor, TCI). These attributes have been implicated in a variety of complications (infection, thromboembolic, gastrointestinal, etc.). To address these concerns, a totally implantable VAD that requires no percutaneous connections and can be implanted in the left hemi-thorax has been developed. The developed device has undergone in vivo evaluation as part of the design and development process. A total of 43 implants in the bovine model, with 5 device versions, have been conducted between July 1992 and February 2000. These studies successfully have demonstrated several important aspects of the developed device, including 1) feasibility of a totally implantable system; 2) capability of the device to support a dysfunctional heart; and 3) ability of the device to provide flows up to 10 L/min in a physiological setting. The studies to date have played a vital role in the design and development process as well as demonstrating the feasibility of a totally implantable intrathoracic VAD. Based on these studies, design optimization was conducted, resulting in the development of the pre-clinical version of the device in preparation for clinical trials