Two-part bi-leaflet heart valve prostheses

Abstract

A two-part heart valve prosthesis comprising a self-expanding valve cage stent and a bi-leaflet tissue valve secured thereto. A method for delivering a heart valve prosthesis to a native valve annulus comprises expanding an expandable frame at the native valve annulus and positioning a replacement heart valve within the expandable frame. The expandable frame preferably includes a first anchoring portion that is positioned on a first side of the native valve annulus and a second anchoring portion that is positioned on a second side of the native valve annulus. The first anchoring portion engages tissue on the first side of the native valve annulus and the second anchoring portion engages tissue on the second side of the native valve annulus for securing the expandable frame to the native valve annulus. The replacement heart valve comprises a plurality of leaflets for replacing the function of the native valve.

What is claimed is: 
     
         1 . A two-part heart valve prosthesis, comprising:
 a self-expanding valve cage stent including a series of struts configured to self-expand to a tubular expanded shape for engaging surrounding tissue; and   a bi-leaflet valve adapted for deployment within a lumen of the valve cage stent, the bi-leaflet valve formed by two leaflets supported by a compressible valve frame made from a memory metal, wherein the two leaflets are capable of rotating between open and closed positions for regulating blood flow through the lumen of the valve cage stent.   
     
     
         2 . The prosthesis of  claim 1 , wherein the leaflets are each defined by a semicircular frame part across which a tissue cover is secured. 
     
     
         3 . The prosthesis of  claim 2 , wherein the frame parts each defining a central slot aligned with a central aperture through a respective tissue cover, and the valve frame is connected to a pair of hinge arms that curve radially outward and pass through the slot and aperture in each leaflet so that the leaflets are hinged to move between the open and closed positions. 
     
     
         4 . The prosthesis of  claim 2 , wherein the tissue covers on the leaflets are connected to each other in a circular cover member having a central aperture through which a central stem of the valve frame passes, the central stem being fixed with respect to the valve cage stent, and the hinge arms are fixed with respect to the central stem. 
     
     
         5 . The prosthesis of  claim 2 , comprising a fabric cover over each tissue cover to provide additional support and minimize leaking. 
     
     
         6 . The prosthesis of  claim 1 , wherein the valve cage stent includes a valve mount suspended within the central lumen and connected to the expanded struts, and the valve frame attaches to the valve mount. 
     
     
         7 . The prosthesis of  claim 6 , wherein the valve frame has a central stem with a snap-on or screw-in mechanism configured to be received in a valve receptacle defined by the valve mount. 
     
     
         8 . The prosthesis of  claim 6 , wherein the valve mount is suspended across a superior rim of the valve cage stent such that the tissue valve is coupled to a superior end of the valve cage stent. 
     
     
         9 . The prosthesis of  claim 8 , wherein the valve mount is suspended by a pair of radial arms extending across the central lumen. 
     
     
         10 . The prosthesis of  claim 1 , further including a guide wire attached to the valve mount to assist in coupling the central stem of the valve frame to the valve mount. 
     
     
         11 . A two-part heart valve prosthesis, comprising:
 a self-expanding valve cage stent including a series of struts configured to self-expand to a tubular expanded shape and engage surrounding tissue, and a valve mount suspended by radial arms at a central axis of a lumen defined by the expanded struts; and   a bi-leaflet tissue valve adapted to connect to the valve mount and comprising an expandable and compressible valve frame made from a memory metal with a pair of leaflets each defined by a semicircular frame part across which a tissue cover is secured, wherein the two leaflets are capable of rotating between open and closed positions for regulating blood flow through the lumen of the valve cage stent.   
     
     
         12 . The prosthesis of  claim 11 , wherein the valve frame has a central stem with a snap-on or screw-in mechanism configured to be received in the valve mount. 
     
     
         13 . The prosthesis of  claim 12 , wherein the tissue covers on the leaflets are connected to each other in a circular cover member having a central aperture through which the central stem passes. 
     
     
         14 . The prosthesis of  claim 12 , wherein the valve frame connects to a pair of hinge arms that curve radially outward and pass through central points on the leaflets so that the leaflets are hinged to move between the open and closed positions. 
     
     
         15 . The prosthesis of  claim 14 , wherein the frame parts each define a central slot aligned with a central aperture through a respective tissue cover, and the hinge arms pass through the slots and apertures in the leaflets. 
     
     
         16 . The prosthesis of  claim 15 , wherein the frame parts each have a strut extending from a straight segment thereof and terminating in a circular eyelet that defines the central slot. 
     
     
         17 . The prosthesis of  claim 11 , wherein the tissue covers are bovine pericardium. 
     
     
         18 . The prosthesis of  claim 17 , comprising a fabric cover over each tissue cover to provide additional support and minimize leaking. 
     
     
         19 . The prosthesis of  claim 11 , wherein the tissue covers are sewn to the frame parts. 
     
     
         20 . The prosthesis of  claim 11 , wherein the valve cage stent further comprises fabric along at least a portion of an interior surface and an exterior surface.