Development of a carbon-coated, central-hinging, bileaflet valve.

Between April 1963 and January 1966, 86 patients at the University of Wisconsin Hospital underwent aortic or mitral valve replacement, or both, with a carbon-coated, central-hinging, bileaflet valve. A 25-year follow-up has been obtained on 43 of these patients discharged with an aortic prosthesis, 13 patients discharged with a mitral prosthesis, and 2 patients discharged with double prostheses. The mean implantation time was 7.2 years, 9.0 years, and 9.5 years, respectively. The longest aortic valve implantation time was 24.2 years in a patient who had her bileaflet valve prophylactically replaced, and the longest mitral implantation time is 24 years in a patient who is doing well with her original prosthesis. We are not aware of any patient among the approximately 700 receiving this valve around the world who has developed fatigue-failure of the silicone-impregnated Teflon fabric leaflet. This valve has demonstrated unexpected durability and has provided some design and biomaterial concepts that are used in a number of current prosthetic valves.