Dynamics of Björk-Shiley Convexo-Concave mitral valves in sheep.

The outlet strut of Björk-Shiley (BSCC) Convexo-Concave heart valves has fractured in some implanted valves resulting in disc escape and emergency reoperation or death. The closing dynamics of BSCC heart valves was studied in situ to determine the forces acting on the outlet strut during valve closure. BSCC valves with strain gages attached to the outlet strut were implanted in the mitral position in sheep.