Beyond implantable first generation cardiac prostheses for treatment of end-stage cardiac patients with clinical results in a multicenter.

After 30 years of research and development effort for both ventricular assist device (VAD) and total artificial heart (TAH) in the United States, they have been demonstrating effectiveness in the bridge to transplantation and destination therapy. Smaller size, long-term durable second generation and third generation blood pumps are now being tested in animals and moving to clinical applications. These are now combined with genetic engineering, tissue engineering and regenerative medical therapy techniques to provide newer treatment methodologies for end-stage cardiac patients. In Japan, heart transplantation was restarted in 1999, but to date only 13 transplants have been performed. Shortage in donor hearts is hindering the prevalence of heart transplantation. Over a dozen of end-stage cardiac patients are waiting for heart transplantation in hospital with a paracorporeal pneumatic VAD. Although implantable VADs have been imported from the USA, they have not acquired a wide clinical use yet because of their large size and high cost. There is a great need for development of a compact, low cost, totally implantable VAD and TAH in Japan to improve the quality of life of end-stage cardiac patients. This paper reviews the current status of the first generation pulsatile VAD and TAH as a bridge to transplantation and destination therapy around the world, followed with a review of the second and third generation blood pumps beyond the limitations of the first generation systems. Future recommendations are also discussed to improve the systems in Japan.