[Disadvantages of mechanical valve prostheses in the surgical treatment of mitral insufficiency].

Various disadvantages may be encountered with mechanical valve prostheses in the surgical management of mitral insufficiency; namely: 1) Early and secondary disinsertion; this is nearly always partial and is usually accompanied by haemolytic anaemial. 2) Infection with nil response to antibiotics. Death from septicaemia may be rapid. Replacement of the prosthesis is otherwise mandatory. 3) Thrombosis, usually partial, accompanied by one or more embolisms. Thrombo-embolism is more frequently noted in the first 6 months after implantation and becomes less common as time passes. 4) Deterioration of the movable part (ball variance) consisting of changes in colour and shape, with swelling and unevenness of the surface, breakage, pitting and loss of elasticity. 5) Low stroke volume syndrome. 6) Erosion of the septum and serious rhythm disturbances. 7) Proliferation of endothelial tissue leading to narrowing of the orifice. 8) Disturbed movement of the movable part, leading to intermittent or permanent blockage and loss of opening or closing play due to the interposition of fibrin and blood clots.