Abstract: A heart valve replacement 12 is characterized by a two-part frame with ring-shaped parts 14, 15 and having cloth coverings 16, 17. At least one leaflet 18 is provided having a margin 18X passing between the two parts 14, 15 of the frame and secured by stitching 19 to the cloth covering 16 of one of the frame parts 14. The frame parts are secured together by stitching 20 between the cloth coverings 16, 17 on the outside of both parts whereby the flexure or hinging line 21 of the leaflet 18 is along the nip between the two cloth-covered frame parts 14, 15. Thus, the line 21 is intermediate the main body of the leaflet 18 and the stitching 19, 20, thereby completely eliminating any possibility of tearing between stitch holes.

Abstract: A bioprosthetic mitral valve replacement comprises a flexible frame (1) having a ring-shaped base (2) and at least a pair of upstanding posts (3), which divide the base into at least two portions (2A, 2B) of varying flexibility, together with animal tissue leaflets (4) each having a periphery consisting of a free portion (4A) extending between the tips (3X) of posts (3) and a fixed portion (4B) secured and sealed to corresponding sides of the posts and the adjacent portion of the base. A bicuspid mitral valve replacement has a pair of posts (3) disposed at opposite ends of a diameter of the undistorted base (2), or displaced therefrom towards the portion (2A) of lesser flexibility to accommodate leaflets (4) of unequal size. The frame (1) is formed of Delrin covered with Dacron cloth, the Delrin having differing thicknesses to either side of the posts (3) which merge into the base (2) by way of a continuous curve (6) on each side.