Oops...we missed the St. Jude Biocor, which has been in use in Europe for many years.
The following study article was written in 2005, which makes Biocor use at least 26 years old:
1Mykén P. Two Decades With The St Jude Med. Biocor Bioprosthesis. Third Biennial Meeting of the Society for Heart Valve Disease, 2005.
A researcher for Hancock II puts their relative 20-year-use freedom from reoperation for SVD (structural valve deterioration) at Hancock II (92%), CP Perimount (92%), and Biocor (76%). However, there are only a handful of of actual people combined in the entire category of those who've had their valves 20 years. This is largely due to the ripe age of most valve recipients (average 69 years old), which allows them to live a full, long, extended life, but still pass on before the 20 year mark. I was unable to locate an all-cause number for a percentage of living recipients who had reoperations for any reason. From:
Twenty-Year Results of the Hancock II Bioprosthesis Michael A. Borger, Joan Ivanov, Susan Armstrong, Debbie Christie-Hrybinsky, Christopher M. Feindel, Tirone E. David. Division of Cardiovascular Surgery, Toronto General Hospital, University Health Network, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
Note that the Myken document puts the Biocor 20-year-use freedom from reoperation for SVD at 86%. As such, researchers disagree. From:
Twenty-Year Experience With the St. Jude Medical Biocor Bioprosthesis in the Aortic Position,
Walter B. Eichinger, MD, Ina M. Hettich, MD, Daniel J. Ruzicka, MD, Klaus Holper, MD, Carolin Schricker, Sabine Bleiziffer, MD, and Ruediger Lange, MD. Department of Cardiovascular Surgery, German Heart Center Munich, Munich, Germany
Freedom from reoperation in our population was 84.0% 4.7% after 20 years. These results are comparable with published outcomes describing other bioprosthetic valves... For the Carpentier-Edwards pericardial valve Jamieson and colleagues published a freedom from valve-related reoperation of 62.3 3.5% at 18 years (mean age, 68.9 10.9 years).
The answer seems to be that the researchers tend to use what numbers they find for references, and they rarely seem to find the same sources as each other.
Best wishes,