Mechanical valve prosthesis, ball cage, CV183.jpg This is a mechanical valve prosthesis of the older ball and cage 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 is at the right into the left ventricle in this mitral valve prosthesis.
A variety of problems can complicate prosthetic heart valves:
  • Thrombosis: this is a major potential problem with mechanical heart valves, requiring that the patient remain on anticoagulant therapy, though this will not entirely prevent thrombosis and subsequent embolization.
  • Infection: vegetations of infective endocarditis can develop on or around the prosthesis, and septic embolization can subsequently occur
  • Structural failure: this is a major problem with bioprostheses, because the leaflets tend to become stiff and calcify.
  • Dehiscence: seen mainly in the immediate postoperative period, dehiscence is separation of the prosthetic valve suture line from the heart, leading to paravalvular leakage
  • Disproportion: the prosthetic valve may not fit well in the heart, so that blood flow is not optimal.