[Experimental study of a new circular semiprosthesis for mitral and tricuspid valve replacement]

The experimental behaviour of a new semiprosthesis for mitral and tricuspid ring plasty is studied. The tolerance of the materials of which the ring is composed was realized by inserting it into the right atrium with hypothermia and occlusion of the cavas, in dogs which were permitted to live 6 months. It was shown that the ring was covered by a very thin, white membrane, with uniform characteristics and strongly attached. The histologic and the ultrastructural study with the electronic microscope, showed proliferation of conjunctive tissue with abundant collaginous fibers. The free border of this covering presented endotheliazation with flat endothelial cells. The prosthetic material behaves as an inert body when there is no evidence of lymphocytes or polymorfonuclears.