Starr-Edward (S-E) Silastic Ball Valve Prosthesis : This was introduced in 1961 by Albert Stm and has different models for mitral and aortic positions. It is a cage and ball valve with the cage made of stellite alloy and ball 111ade of silicone rubber containing barium sulphate. The haemodynamics of any mechanical valve depends on the effective orifice area (EOA). Starr-Edward (S-E) has one of the lowest effective orifice areas (EOA). These valves need life long anticoagulation and antibiotic prophylaxis against prosthetic valve endoearditis. Mechanical failure is unreported.