Implantable valve prosthesis and method for manufacturing such a valve

Abstract

The invention relates to an implantable valve prosthesis, optionally comprising a support structure and at least one valve leaflet. The valve prosthesis comprises a material structure of unidirectional reinforcing elements of drawn ultra high molecular weight polyolefin, extending in at least two directions, wherein the modulus of elasticity of the polyolefin reinforcing elements is at least 60 GPa. The invention furthermore relates to a method for manufacturing such an implantable valve. The valve is easily manufactured and has an improved durability.

1 . Implantable valve prosthesis ( 40 ), comprising at least one valve leaflet ( 44 ) and made of a material structure of unidirectional reinforcing elements of drawn ultra high molecular weight polyolefin ( 11 ,  110 ,  111 ), extending in at least two directions, wherein the modulus of elasticity of the polyolefin reinforcing elements is at least 60 GPa. 
     
     
         2 . Valve prosthesis according to  claim 1 , further comprising a support structure ( 31 ,  43 ) for the at least one valve leaflet. 
     
     
         3 . Valve prosthesis according to  claim 1 , wherein the thickness of the reinforcing elements ( 11 ,  110 ,  111 ) is less than 40 micrometer, more preferably less than 30 micrometer and most preferably less than 20 micrometer. 
     
     
         4 . Valve prosthesis according to  claim 1 , wherein the material structure comprises at least one woven fabric or knitted braid ( 11 ) of the reinforcing elements ( 110 ,  111 ) of drawn ultra high molecular weight polyolefin, preferably the material structure consist of one woven fabric or knitted braid ( 11 ) of the reinforcing elements ( 110 ,  111 ) of drawn ultra high molecular weight polyolefin. 
     
     
         5 . Valve prosthesis according to  claim 1 , wherein the material structure comprises a plurality of superimposed multilayered material sheets ( 11 ), the sheets comprising a consolidated stack of monolayers of the reinforcing elements of drawn ultra high molecular weight polyolefin, whereby the draw direction of two subsequent monolayers in the stack differs. 
     
     
         6 . Valve prosthesis according to  claim 1 , wherein the reinforcing elements ( 110 ,  111 ) comprise fibers and/or tapes. 
     
     
         7 . Valve prosthesis according to  claim 1 , wherein the valve prosthesis is essentially free of matrix binder. 
     
     
         8 . Valve prosthesis according to  claim 1 , wherein the material structure ( 11 ) comprises a plurality of reinforcing elements ( 110 ,  111 ) embedded in a matrix binder. 
     
     
         9 . Valve prosthesis according to  claim 1 , wherein the polyolefin comprises polyethylene, preferably the polyolefin comprises UHMWPE and more preferably the polyolefin is substantially UHMWPE. 
     
     
         10 . Valve prosthesis according to  claim 1 , wherein the thickness of the material structure is between 50 and 500 micrometer, preferably between 80 and 400 micrometer and most preferably between 150 and 250 micrometer. 
     
     
         11 . Valve prosthesis according to  claim 1 , wherein the at least one valve leaflet ( 44 ) is integrally formed with at least a part of the support structure ( 31 ,  43 ). 
     
     
         12 . Valve prosthesis according to  claim 1 , wherein the support structure ( 43 ) is at least partly made from shape memory alloy, or from superelastic alloy. 
     
     
         13 . Method of manufacturing an implantable valve prosthesis ( 40 ), comprising the steps of:
 providing a material structure ( 11 ) of unidirectional reinforcing elements ( 110 ,  111 ) of drawn ultra high molecular weight polyolefin, extending in at least two directions, wherein the modulus of elasticity of the polyolefin reinforcing elements is at least 60 GPa;   shaping the material structure ( 11 ) in the form of at least a part of the valve prosthesis ( 40 ); and   consolidating the material structure under elevated temperature and pressure.   
     
     
         14 . Method according to  claim 14 , wherein a matrix binder is applied onto the material structure and consolidated with it under elevated temperature and pressure. 
     
     
         15 . Valve prosthesis according to  claim 1 , the valve prosthesis being a heart valve prosthesis.