Valve prosthesis for implantation in body channels

Abstract

A valve prosthesis which is especially useful in the case of aortic stenosis and capable of resisting the powerful recoil force and to stand the forceful balloon inflation performed to deploy the valve and to embed it in the aortic annulus, comprises a collapsible valvular structure and an expandable frame on which said valvular structure is mounted. The valvular structure is composed of physiologically compatible valvular tissue that is sufficiently supple and resistant to allow the valvular structure to be deformed from a closed state to an opened state. The valvular tissue forms a continuous surface and is provided with strut members that create stiffened zones which induce the valvular structure to follow a patterned movement in its expansion to its opened state and in its turning back to its closed state.

1 . A method for treating a native aortic valve in a human heart, comprising: 
 advancing an expandable member to a position within the native aortic valve, the native aortic valve having at least two valvular leaflets;    dilating the native aortic valve by expanding the expandable member to push aside the valvular leaflets of the native aortic valve;    collapsing the expandable member and withdrawing the expandable member from the native aortic valve;    advancing a prosthetic valve to a position within the dilated native aortic valve, the prosthetic valve being radially compressed during the advancement; and    radially expanding the prosthetic valve within the dilated aortic valve, wherein the expanded prosthetic valve maintains the native aortic valve in the dilated condition and replaces the valvular function of the native aortic valve.    
     
     
         2 . The method of  claim 1 , wherein the prosthetic valve is advanced percutaneously through the aorta in a retrograde direction.  
     
     
         3 . The method of  claim 1 , wherein the prosthetic valve comprises a metallic frame and a valvular structure coupled to the frame.  
     
     
         4 . The method of  claim 3 , wherein the valvular structure comprises biological tissue.  
     
     
         5 . The method of  claim 3 , wherein the metallic frame is viewed under fluoroscopy during advancement of the prosthetic valve toward the native aortic valve.  
     
     
         6 . The method of  claim 3 , wherein the metallic frame engages the valvular leaflets of the native aortic valve.  
     
     
         7 . The method of  claim 6 , wherein the prosthetic valve is positioned such that valvular leaflets provide a stable base for fixing the metallic frame within the native aortic valve.  
     
     
         8 . The method of  claim 7 , wherein the valvular leaflets recoil inward after dilatation to further contribute to the fixation of the metallic frame.  
     
     
         9 . The method of  claim 3 , wherein the metallic frame is made of steel.  
     
     
         10 . The method of  claim 3 , wherein the metallic frame has a height between about 10 and 15 millimeters in the radially expanded condition.  
     
     
         11 . The method of  claim 3 , wherein the metallic frame has a top end and a bottom end and wherein the top end of the frame is located below the coronary ostia after the prosthetic valve is expanded such that the coronary ostia remain free of obstruction from the prosthetic valve.  
     
     
         12 . The method of  claim 11 , wherein the bottom end of the frame is located above the mitral valve in the human heart after the prosthetic valve is expanded such that the mitral valve remains free of obstruction from the prosthetic valve.  
     
     
         13 . The method of  claim 1 , wherein the native aortic valve is dilated to a diameter of at least about 20 millimeters before advancing the prosthetic valve.  
     
     
         14 . A method for treating a native valve in a human heart, comprising: 
 advancing an expandable balloon to a position within the native valve, the native valve having at least two valvular leaflets;    dilating the native valve by inflating the balloon to push aside the valvular leaflets;    deflating the balloon and withdrawing the balloon from the native valve;    advancing an expandable prosthetic valve to a position within the dilated native valve, the prosthetic valve including a valvular structure coupled to an expandable frame; and    radially expanding the prosthetic valve within the dilated native valve, wherein an outer surface of the expandable prosthetic valve engages the leaflets of the native valve and the expandable prosthetic valve replaces the function of the native valve.    
     
     
         15 . The method of  claim 14 , wherein the valvular structure has a truncated shape.  
     
     
         16 . The method of  claim 15 , wherein the valvular structure has a hyperboloid shape.  
     
     
         17 . The method of  claim 14 , wherein the frame is manufactured in an expanded condition and the valvular structure is coupled to the frame while the frame is in the expanded condition and further comprising compressing the frame and valvular structure before advancement toward the dilated native valve.  
     
     
         18 . The method of  claim 14 , wherein the native valve is a mitral valve and the prosthetic valve is advanced percutaneously using a transseptal route.  
     
     
         19 . The method of  claim 18 , wherein the prosthetic valve has an expanded diameter of at least about 30 millimeters.  
     
     
         20 . A method of implanting a prosthetic valve in a heart for treating valvular aortic stenosis, comprising: 
 providing a first elongate catheter having an expandable balloon disposed along a distal end portion thereof;    positioning the balloon within an aortic valve by manipulation of the first elongate catheter;    expanding the balloon to dilate the aortic valve;    collapsing the balloon and withdrawing the first elongate catheter through the aorta;    providing a second elongate catheter having an expandable prosthetic valve disposed along a distal end portion thereof;    advancing the second elongate catheter through the aorta toward the dilated aortic valve;    deploying the prosthetic valve within the dilated aortic valve; and    withdrawing the second elongate catheter through the aorta.