Mitral Valve Prosthesis and Methods for Implantation

Abstract

Apparatus and methods are provided including a mitral valve prosthesis. The prosthesis includes an inner support structure having downstream and upstream sections, the upstream section having a cross-sectional area greater than the downstream section. The inner support structure is configured to be positioned on an atrial side of the native valve complex, and to prevent the prosthesis from being dislodged into the left ventricle. A prosthetic valve having prosthetic valve leaflets is coupled to the inner support structure. An outer support structure has engagement arms, downstream ends of the engagement arms being coupled to the inner support structure. The prosthesis is configured such that, upon implantation thereof: downstream ends of the native valve leaflets, downstream ends of the engagement arms, and downstream ends of the prosthetic leaflets, are disposed at a longitudinal distance from one another of less than 3 mm. Other embodiments are also described.

1 - 25 . (canceled) 
     
     
         26 . A mitral valve prosthesis for implantation at a native mitral valve complex of a subject, comprising:
 an inner support structure having a downstream section, and an upstream section, wherein the upstream section has a cross-sectional area greater than the downstream section, the inner support structure being configured to be positioned at least partially on an atrial side of the native valve complex, and to apply an axial force directed toward a left ventricle; and   an outer support structure having posterior and anterior engagement arms configured to be placed over native leaflets of the native mitral valve complex, wherein the engagement arms are coupled to the inner support structure,   the engagement arms being configured to define first configurations thereof during implantation of the prosthesis, and to change shape so as to define second configurations thereof, subsequent to being placed over the native leaflets of the native mitral valve complex, each of the engagement arms spanning a width of less than 12 mm in the first configuration thereof, and spanning a width of more than 15 mm when in the second configuration thereof.   
     
     
         27 . The mitral valve prosthesis according to  claim 26 , wherein, in the first configuration thereof, the engagement arms are configured to span a width of less than 8 mm. 
     
     
         28 . The mitral valve prosthesis according to  claim 26 , wherein, in the second configuration thereof, the engagement arms are configured to span a width of more than 35 mm. 
     
     
         29 . The mitral valve prosthesis according to  claim 26 , wherein, in the first configuration thereof, the engagement arms are configured to facilitate functioning of the native valve complex during implantation of the prosthesis. 
     
     
         30 . The mitral valve prosthesis according to  claim 26 , wherein, in the first configuration thereof, the engagement arms are configured to fit between papillary muscles of the native valve complex. 
     
     
         31 - 40 . (canceled) 
     
     
         41 . A heart valve prosthesis comprising:
 a frame comprising:
 an expandable inner support structure having a radially compressed configuration and a radially expanded configuration, the expandable inner support structure including an inflow section and an outflow section, wherein in the radially expanded configuration the inflow section is flared radially outward from the inflow section, wherein the inflow section in the radially expanded configuration is asymmetrically shaped such that the inflow portion includes a first portion and a second portion disposed radially opposite the first portion, wherein the first portion extends radially farther from a central longitudinal axis of the heart valve prosthesis than the second portion, and wherein a first length from an outflow end of the outflow section to the first portion is longer than a second length from the outflow end of the outflow section to the second portion, the first and second lengths being measured parallel to the central longitudinal axis; and 
 an outer support structure coupled to the inner support structure; and 
   a valve structure attached to the frame within an interior area of the inner support structure.   
     
     
         42 . The heart valve prosthesis of  claim 41 , wherein the inflow section comprises a plurality of cells. 
     
     
         43 . The heart valve prosthesis of  claim 42 , wherein the outflow section comprises a plurality of cells. 
     
     
         44 . The heart valve prosthesis of  claim 41 , wherein the outflow section has a circular cross-section. 
     
     
         45 . The heart valve prosthesis of  claim 41 , wherein the outflow section is configured to expand within and support against a native valve annulus. 
     
     
         46 . The heart valve prosthesis of  claim 41 , wherein the outer support structure includes first and second engagement arms configured to capture native valve leaflets between the first and second engagement arms and an outer surface of the inner support structure. 
     
     
         47 . The heart valve prosthesis of  claim 46 , wherein the outer support structure includes first and second commissure posts, wherein the first and second engagement arms are coupled to the first and second commissure posts. 
     
     
         48 . The heart valve prosthesis of  claim 41 , wherein the inflow section is configured to expand within and support against an atrium. 
     
     
         49 . The heart valve prosthesis of  claim 41 , wherein the frame further comprises fixation barbs attached to the inflow section. 
     
     
         50 . The heart valve prosthesis of  claim 41 , wherein in the radially expanded configuration the inflow section is D-shaped.