The past half century has witnessed enormous advances in the development and refinement of implantable medical devices such as heart valves, joint replacements, and pacemakers/defibrillators. For the most part, these devices have improved the quality and, in some cases, the duration of human life. Unfortunately, occasional unexpected adverse events have and will continue to occur (e.g., the recently reported problems with hip replacements and cardiac pacemaker/ defibrillator leads), with the result that very careful monitoring of new devices is now recognized to be an essential component of the evaluation of health services and the protection of patients. Fracture of the outlet strut of the Björk-Shiley convexo-concave (BSCC) heart valve was one of the first and most catastrophic of these adverse events.
The B.S. valve, originally released in 1978,was approved by the Food and Drug Administration (FDA) in 1979, after which large numbers were distributed by Pfizer Inc., for implantation worldwide. During the next several years, multiple instances of catastrophic failure of the B.S. valve, often with patient death, were reported These reports resulted in numerous wrongful death lawsuits.