Atraumatic stent with reduced deployment force, method for making the same and method and apparatus for deploying and positioning the stent

Abstract

An implantable stent includes a plurality of elongate wires braided to form a hollow tubular structure having a tubular wall to define an interior surface and an exterior surface and having opposed open first and second ends, wherein the opposed open first and second ends are atraumatic ends. The atraumatic ends of the stent are desirably free of any loose wire ends. The wires include composite wires to enhance visibility of the wires to provide improved external imaging of the wires in the body. The elongate composite wires of the stent may be metallic wires having an outer metallic portion including a first metal, such as nitinol, and an inner metallic core portion including a second metal, which is a radiopaque material, such as gold, barium sulfate, ferritic particles, platinum, platinum-tungsten, palladium, platinum-iridium, rhodium, tantalum or combinations thereof.

1 - 20 . (canceled) 
     
     
         21 . A method for making an implantable stent with at least one atraumatic end, comprising:
 providing a plurality of elongate wires; and   braiding said plurality of elongated wires to form a hollow tubular structure having a tubular wall to define an interior surface and an exterior surface and having opposed open first and second ends, wherein said opposed open first and second ends are atraumatic ends;   terminating said plurality of elongate wires at said second end;   shaping said plurality of elongate wires at said first end into a plurality of closed loops with each loop having an apex defined by a bend in one of said wires and having an opposed base;   arranging said plurality of closed loops into a series of closed loops, wherein said apex of adjacent closed loops are longitudinally offset from one and the other; and   crossing adjacent said plurality of elongate wires at said opposed base.   
     
     
         22 . The method of  claim 21 , wherein, wherein said elongate wires comprise composite wires to enhance visibility of the wires to provide improved external imaging of the wires in the body. 
     
     
         23 . The method of  claim 22 , wherein the enhanced visibility is enhanced radiopacity and the external imaging is fluoroscopic or x-ray visualization. 
     
     
         24 . The method of  claim 21 , further comprising:
 aligning said wires at said second end into a plurality of mated adjacent wires to define a plurality of juxtaposed regions; and   securably joining said mated adjacent wires to one and the other at said juxtaposed regions to define a closed loop at said second end, wherein each of said closed loop is spaced apart from said other closed loop.   
     
     
         25 . The method of  claim 24 , wherein the step of securably joining said wires includes welding said wires. 
     
     
         26 . A method for making an implantable stent comprising:
 providing a plurality of elongate wires;   braiding said wires to form a hollow tubular structure having a tubular wall to define an interior surface and an exterior surface and having opposed open first and second ends, wherein said opposed open first and second ends are atraumatic ends,   terminating said wires at said second end to form terminated wire ends;   aligning said wires at said second end into a plurality of mated adjacent wires to define a plurality of juxtaposed regions;   securably joining said mated adjacent wires to one and the other at said juxtaposed regions to define a plurality of securably joined regions;   shaping said plurality of elongate wires at said first end into a plurality of closed loops with each loop having an apex defined by a bend in one of said wires and having an opposed base;   arranging said plurality of closed loops into a series of closed loops, wherein said apex of adjacent closed loops are longitudinally offset from one and the other;   crossing adjacent said plurality of elongate wires at said opposed base; and   smoothing said terminated wire ends from said wire ends.   
     
     
         27 . The method of  claim 26 , wherein the step of securably joining said wires includes welding said wires, and further wherein said securably joined regions are welds. 
     
     
         28 . The method of  claim 26 , wherein said elongate wires comprise composite wires to enhance visibility of the wires to provide improved external imaging of the wires in the body. 
     
     
         29 . (canceled) 
     
     
         30 . The method of  claim 35 , wherein the step of securably joining said wires includes welding said wires, and further wherein said securably joined regions are welds. 
     
     
         31 . The method of  claim 35 , wherein said elongate wires comprise composite wires to enhance visibility of the wires to provide improved external imaging of the wires in the body. 
     
     
         32 . The method of  claim 26 , wherein the step of smoothing said wire ends includes diagonally cutting each of said wire ends. 
     
     
         33 . The method of  claim 26 , wherein the step of smoothing said wire ends includes chemically treating each of said wire ends. 
     
     
         34 . The method of  claim 26 , wherein the step of smoothing said wire ends includes each wire end having a radius of curvature. 
     
     
         35 . A method for making an implantable stent comprising:
 providing a plurality of elongate wires;   braiding said plurality of elongate wires to form a hollow tubular structure having a tubular wall to define an interior surface and an exterior surface and having opposed open first and second ends, wherein said opposed open first and second ends are atraumatic ends,   terminating said wires at said second end;   aligning said wires at said second end into a plurality of mated adjacent wires to define a plurality of juxtaposed regions;   extending at least one of said mated stent wires to provide an extended stent wire;   looping said extended stent wire so the extended end abuts a proximal pair of stent wires;   securably joining said mated adjacent wires to one and the other at said juxtaposed regions; and   securably joining said extended and looped wire to said proximal pair of wires with a pair of longitudinally offset securably joined regions, wherein said looped wire is spaced apart from an adjacent looped wire.   
     
     
         36 . The method of  claim 35 , further including the step of smoothing said terminated wire ends by removing sharp edges from said wire ends. 
     
     
         37 . The method of  claim 35 , wherein the step of smoothing said wire ends includes diagonally cutting each of said wire ends. 
     
     
         38 . The method of  claim 35 , wherein the step of smoothing said wire ends includes chemically treating each of said wire ends. 
     
     
         39 . An implantable stent comprising:
 a plurality of elongate wires braided to form a hollow tubular structure having a tubular wall to define an interior surface and an exterior surface and having opposed open first and second ends, wherein said opposed open first and second ends are atraumatic ends,   wherein said wires terminate at said second end defining terminating wire ends, said terminating wire ends have smooth ends devoid of sharp edges, said wires at said second end being aligned into a plurality of mated adjacent wires to define a plurality of juxtaposed regions; at least one of said mated stent wires extends to provide an extended stent wire; said extended stent wire is looped so the extended end abuts a proximal pair of stent wires; said mated adjacent wires is securably joined to one and the other at said juxtaposed regions; and said extended and looped wire are securably joined to said proximal pair of wires with a pair of longitudinally offset securably joined regions, wherein said looped wire is spaced apart from an adjacent looped wire; and   said wires at said first end are arranged in a series of closed loops with each loop having an apex defined by a bend in one of said wires and having an opposed base defined by crossing of adjacent wires, said apex of adjacent closed loops are longitudinally offset from one and the other.   
     
     
         40 . The stent of  claim 39 , wherein each of said smooth ends are chemically treated to provide said smooth ends. 
     
     
         41 . The method of  claim 39 , wherein the step of smoothing said wire ends includes diagonally cutting each of said wire ends. 
     
     
         42 . The stent of  claim 39 , wherein each of said smooth ends has a radius of curvature.