The history of the Björk-Shiley tilting disc valve.

After observing a high residual gradient and a high mortality in patients with a narrow aortic root undergoing aortic valve replacement with a small ball valve during the period 1962-1965, it was most gratifying to find a much smaller gradient in similar patients with the Wada-Cutter valve in 1968. A tilting disc valve seemed a solution, particularly for patients with narrow aortic root, but the disc had to rotate to eliminate localized wear in a hinge mechanism. Together with Donald P. Shiley, I tested a tilting disc valve with a rotating disc of Delrin, for wear and also in a pulse duplicator in 1968. Because the function was much better than that of the clinically popular Starr-Edwards ball valve prosthesis, the Björk-Shiley valve was first inserted in a patient on January 19, 1969. My clinical experience and judgement justified the omission of animal trial; such trial would have been irrelevant.