MEDICAL INSTRUMENT, RING PROSTHESIS, STENT AND STENTED VALVE

The present invention relates to a prosthesis for attachment in a passage surrounded by tissue.The prosthesis comprises a tubular element formed from memory material with a proximal and distal flange which extend around the tubular element. The distal and proximal flange have a radial position eith respect to the tubular element for clamping tissue surrounding the passage between the distal and proximal flange. The distal flange and proximal flange consist of distal flange feet respectively proximal flange feet, which are bendable from the radial position to an extended position, in which the distal and proximal flange feet extend in the longitudinal direction of the tubular element. The distal and/or proximal flange feet, at the ends attached to the tubular element, are provided on the side facing the proximal respectively distal flange with a filling which is designed, in the radial position of the distal and proximal flange, to increase the clamping force with which the distal and proximal flange clamp the tissue in situ. The distal and/or proximal flange feet, respectively, have a concave-curved part which follows on from the ends of the distal and/or proximal flange feet, respectively, being attached to the tubular element, the hollow side of the concave-curved part facing towards the proximal and/or distal flange, respectively, and the filling being provided in the hollow side of the concave-curved part.