Have you reviewed the Technological Advancements offered by the On-X Valve (see
www.onxvalves.com)?
1- harder and smoother surfaces due to patented improvements to the Pyrolytic Carbon (reduces potential for Clot formation)
2- Leaflets open a full 90 degrees (vs. 75 to 85 degrees for older designs) resulting in Low or NO Turbulence (reduces potential for clot formation and improved hemodynamics)
3 - improved Pivot Design - reduces damage to Red Blood Cells (Hemolysis)
4 - Barrier to retard or prevent Pannus Tissue Growth
(only valve with this feature)
5- reported to have Low Contact Noise (two contact points)
Did you know that ALL of the currently popular mechanical Valves (in USA) were designed in large part by Jack Bokros, Ph.D. (and his associates), who developed Pyrolytic Carbon in 1963 for an application in Nuclear Power systems but realized it's benefit in blood-contact applications and has been designing Heart Valves ever since?
Jack Bokros worked with St. Jude to develop the Pyrolytic Carbon Bi-Leaflet Valve in 1976. He founded Carbomedics in 1979, holds the patents on Carbomedics and ATS Valves (1985).
Jack Bokros founded Medical Carbon Research Institute in 1994 which produced the On-X Valves beginning in 1996.
Approximately 70,000 On-X Valves have been implanted World Wide in ~64 countries as of 2008.
(from information supplied by On-X)