Mechanical valve prosthesis, tilting disk, CV182.jpg This is a mechanical valve prosthesis of the more modern tilting disk variety. Such mechanical prostheses will last indefinitely from a structural standpoint, but the patient requires continuing anticoagulation because of the exposed non-biologic surfaces. The superior aspect (here the left atrium) is seen at the left, while the outflow, with the two leaflets tilted outward toward the left ventricle, is at the right in this mitral valve prosthesis.