Radiopaque super-elastic intravascular stent

Abstract

The intravascular stent is formed from a composite wire includes an inner core of radiopaque metal, a polymer layer coaxially disposed about the inner core, and an outer metal layer coaxially disposed about the polymer layer. The intermediary polymer layer acts as a barrier material between the inner core and the outer sheath, so that the inner core and outer sheath may be made of dissimilar metallic layers, and the intermediary polymer layer will prevent a galvanic reaction between the inner core and the peripheral metal layer. The intravascular stent has ends flared radially outwardly to prevent radially and longitudinally inward deformation of the ends of the stent when the stent is disposed in a desired location in a patient's vasculature.

1 . A composite wire, comprising:
 an elongated inner core having a selected length and formed from a radiopaque metal;   an outer metal layer disposed around said elongated inner core along the length of said elongated inner core, wherein said elongated inner core and said outer metal layer are made of dissimilar metals; and   a continuous intermediate polymer layer disposed between said outer metal layer and said elongated inner core, said continuous intermediate polymer layer being configured to insulate said elongated inner core and said outer metal layer from galvanic corrosion between said elongated inner core and said outer metal layer.   
     
     
         2 . The composite wire of  claim 1 , wherein the radiopaque metal is selected from the group consisting of platinum, tantalum, gold, and combinations thereof. 
     
     
         3 . The composite wire of  claim 1 , wherein the inner core is cylindrical. 
     
     
         4 . The composite wire of  claim 1 , wherein the inner core is disposed centrally along a longitudinal axis of the composite wire. 
     
     
         5 . The composite wire of  claim 1 , wherein the outer metal layer is formed of a superelastic alloy. 
     
     
         6 . The composite wire of  claim 1 , wherein the outer metal layer is formed of a nickel-titanium alloy. 
     
     
         7 . The composite wire of  claim 1 , wherein the composite wire is formed as a cylindrical wire.