Valve prosthesis

Abstract

The present disclosure relates to valve replacement devices that are foldable for catheter-based deployment to the site of implantation, as well as systems for the delivery of valve prostheses, including prostheses having the special characteristics of the disclosed valve replacement devices. The devices include highly effective adhering mechanisms for secure and enduring precision implantation. The adhering mechanisms may employ a unique sealing mechanism that includes a cuff that expands slowly whereby the device is not secured in place until the completion of the implantation procedure. The implanted device, optionally together with the cuff, prevents perivalvular leaks and incorporate an appropriate leaflet system for reliable functioning in situ.

1 .- 24 . (canceled) 
     
     
         25 . A mitral valve prosthesis comprising:
 a stent having an expanded and an unexpanded state and that includes
 a long axis; 
 a middle region having first and second ends and comprising a framework that defines inner and outer surfaces; 
 a lower flange portion at the first end of the middle region that comprises a plurality of flange elements, each of said elements having a first end that is attached to the middle region and an opposed second end that is spaced from the first end; 
   and,
 an upper flange portion at the second end of the middle region that comprises a plurality of flange elements, each of said elements having a first end that is attached to the middle region and an opposed second end that is spaced from the first end; 
   and,   a valve that is attached to the inner surface of the middle region of the stent,   wherein,   when said stent is in the unexpanded state, the upper and lower flange portions are oriented substantially along the long axis of the stent;   when said stent transitions from the unexpanded state to the expanded state, the lower flange portion transitions in space so that it is no longer oriented substantially along the long axis of the stent; and,   the lower flange portion grasps tissue at the ventricular side of the annulus by enfolding it between the lower flange portion and the outer surface of the middle region as the stent transitions from the unexpanded state to the expanded state.   
     
     
         26 . The valve prosthesis according to  claim 25  wherein the lower flange portion anchors the stent within the mitral annulus by grasping the subvalvular apparatus at the ventricular side of the annulus. 
     
     
         27 . The valve prosthesis according to  claim 25  wherein the lower flange portion grasps leaflets of the native mitral valve by enfolding the leaflets between the lower flange portion and the outer surface of the middle region in order to anchor the stent within the mitral annulus. 
     
     
         28 . The valve prosthesis according to  claim 25  wherein the lower flange portion anchors the stent within the mitral annulus by grasping chordea at the ventricular side of the annulus. 
     
     
         29 . The valve prosthesis according to  claim 25  wherein the lower flange portion anchors the stent within the mitral annulus by grasping a left ventricular wall. 
     
     
         30 . The valve prosthesis according to  claim 25  wherein the upper flange portion anchors the stent within the mitral annulus by grasping tissue between the upper flange portion and the outer surface of the middle region. 
     
     
         31 . The valve prosthesis according to  claim 25  wherein the upper flange portion anchors the stent within the mitral annulus by grasping left atrial tissue. 
     
     
         32 . The valve prosthesis according to  claim 25  wherein the lower flange portion is oriented at an oblique angle relative to the long axis of the stent when the stent is in the expanded state. 
     
     
         33 . The valve prosthesis according to  claim 25  wherein the lower flange portion is oriented substantially parallel relative to the long axis of the stent when the stent is in the unexpanded state. 
     
     
         34 . The valve prosthesis according to  claim 25  wherein said stent is self-expanding. 
     
     
         35 . The valve prosthesis according to  claim 25  wherein the stent comprises a wire weave. 
     
     
         36 . The valve prosthesis according to  claim 25  wherein the upper flange portion is oriented at an oblique angle relative to the long axis of the stent when the stent is in the expanded state. 
     
     
         37 . The valve prosthesis according to  claim 25  wherein the upper flange portion is oriented substantially parallel relative to the long axis of the stent when the stent is in the unexpanded state. 
     
     
         38 . The valve prosthesis according to  claim 25  wherein when said stent transitions from the unexpanded state to the expanded state, the upper flange portion transitions in space so that it is no longer oriented substantially along the long axis of the stent. 
     
     
         39 . The valve prosthesis according to  claim 38  wherein the upper flange portion grasps tissue at the atrial side of the annulus by enfolding it between the upper flange portion of the outer surface of the middle region as the stent transitions from the unexpanded state to the expanded state. 
     
     
         40 . The valve prosthesis according to  claim 25  wherein when said stent transitions from the unexpanded state to the expanded state, the second ends of the flange elements of the lower flange portion move towards the middle region of the stent. 
     
     
         41 . The valve prosthesis according to  claim 25  wherein when said stent transitions from the unexpanded state to the expanded state, the second ends of the flange elements of the upper flange portion move towards the middle region of the stent. 
     
     
         42 . The valve prosthesis according to  claim 25  wherein when said stent transitions from the unexpanded state to the expanded state, the second ends of the flange elements of the lower flange portion orient away from the longitudinal axis of the stent. 
     
     
         43 . The valve prosthesis according to  claim 25  wherein when said stent transitions from the unexpanded state to the expanded state, the second ends of the flange elements of the upper flange portion orient away from the longitudinal axis of the stent.