It was the genius of Gordon Murray in Toronto that introduced the use of allografts into cardiac surgery in the 1950s. Soon after this on opposite sides ofthe world, Sir Brian Barratt-Boyes in Auckland, New Zealand, and Mr. Donald Ross in London, undertook to use allografts for the replacement of diseased aortic valves. Since that time the global interest in allografts has been patchy, episodic, and without a con sensus. Nonetheless, for the last 20 years at least three groups in the world have steadfastly pursued the development of new and relevant information concerning the use of allograft...