Expandable stent and method for delivery of same

Abstract

An expandable stent comprising a proximal end and a distal end in communication with one another and a tubular wall disposed between the proximal end and the distal end. The tubular wall has a longitudinal axis and a porous surface defined by a plurality of intersecting members comprising a series of longitudinal struts disposed substantially parallel to the longitudinal axis of the stent. Each longitudinal strut in the series comprises flexure means for substantially complementary extension and compression of a diametrically opposed pair of the longitudinal struts upon flexure of the stent. The stent is expandable from a first, contracted position to a second, expanded position upon the application of a radially outward force on the stent. The provision of such flexure means in the series of longitudinal struts leads to a very desirable balance of lateral flexibility of the unexpanded stent and radial rigidity of the expanded stent.

1 . A stent comprising:
 a series of undulating circumferential struts;   a plurality of longitudinal struts connecting said series of undulating circumferential struts to form a porous, cylindrical surface; and   flexure elements within said plurality of longitudinal struts, said plurality of longitudinal struts being arranged around said cylindrical surface such that the flexure elements in adjacent longitudinal portions are located at different distances from said circumferential struts.   
   
   
       2 . The stent of  claim 1 , wherein one or more of said plurality of longitudinal portions includes multiple flexure elements within the same longitudinal portion. 
   
   
       3 . The stent of  claim 2 , wherein all said multiple flexure elements within the same longitudinal portion have a same shape. 
   
   
       4 . The stent of  claim 2 , wherein all said multiple flexure elements within the same longitudinal portion have a different shape. 
   
   
       5 . The stent of  claim 2 , wherein all said multiple flexure elements within the same longitudinal portion have a first lateral section and a second lateral section, and wherein the first lateral section and the second lateral section are present on the same side of the longitudinal portion. 
   
   
       6 . The stent of  claim 2 , wherein all said multiple flexure elements within the same longitudinal portion have a first lateral section and a second lateral section, and wherein the first lateral section and the second lateral section are present on different sides of the longitudinal portion. 
   
   
       7 . The stent defined in  claim 1 , wherein a relative flexibility of the stent is variable in accordance with a thickness of at least one of the plurality of radially-expandable circumferential struts varying in the range of from about 0.0015 to about 0.0045 inches. 
   
   
       8 . The stent defined in  claim 1 , further comprising a medicinal coating disposed thereon. 
   
   
       9 . A stent system comprising a balloon catheter having an expandable portion, the expandable portion having disposed thereon the stent defined in  claim 8 . 
   
   
       10 . The stent defined in  claim 1 , wherein said multiple flexure elements within the same longitudinal strut have substantially the same shape and differing size. 
   
   
       11 . The stent defined in  claim 1 , wherein said multiple flexure elements within the same longitudinal strut have differing shape and size. 
   
   
       12 . The stent defined in  claim 1 , wherein the porous, cylindrical surface comprises a repeating pattern comprised of a polygon having a pair of side walls substantially parallel to a stent longitudinal axis, and wherein the flexure elements are disposed in each of the side walls. 
   
   
       13 . The stent defined in  claim 1 , wherein the longitudinal struts are aligned in a spaced relationship parallel to a stent longitudinal axis. 
   
   
       14 . The stent defined in  claim 1 , wherein the longitudinal struts are aligned in an interconnected relationship parallel to a stent longitudinal axis. 
   
   
       15 . The stent defined in  claim 1 , wherein the stent is constructed of stainless steel. 
   
   
       16 . The stent defined in  claim 1 , wherein the stent is constructed of a self-expanding material. 
   
   
       17 . The stent defined in  claim 16 , wherein the self-expanding material comprises nitinol. 
   
   
       18 . The stent defined in  claim 16 , wherein the self-expanding material expands at a temperature of greater than about 30° C. 
   
   
       19 . The stent defined in  claim 1 , wherein said flexure elements, in two dimensions, have a width less than a width of said undulating circumferential struts. 
   
   
       20 . The stent defined in  claim 1 , wherein adjacent undulating circumferential struts have substantially the same profile. 
   
   
       21 . The stent defined in  claim 1 , wherein adjacent undulating circumferential struts have substantially different profiles. 
   
   
       22 . A stent comprising:
 a series of undulating circumferential members;   a plurality of longitudinal members connecting said series of undulating circumferential members to form a porous, cylindrical surface; and   flexure members within said plurality of longitudinal members, the flexure members of adjacent longitudinal members having different shapes in an unbent form of the stent.   
   
   
       23 . The stent of  claim 22 , wherein one or more of said plurality of longitudinal members includes multiple flexure members within the same longitudinal member. 
   
   
       24 . The stent of  claim 23 , wherein said multiple flexure members within the same longitudinal member have a same shape. 
   
   
       25 . The stent of  claim 23 , wherein said multiple flexure members within the same longitudinal member have a different shape. 
   
   
       26 . The stent of  claim 23 , wherein said multiple flexure members within the same longitudinal member have a first lateral section and a second lateral section, and wherein the first lateral section and the second lateral section are present on the same side of the longitudinal member. 
   
   
       27 . The stent of  claim 23 , wherein said multiple flexure members within the same longitudinal member have a first lateral section and a second lateral section, and wherein the first lateral section and the second lateral section are present on different sides of the longitudinal member. 
   
   
       28 . The stent defined in  claim 22 , wherein a relative flexibility of the stent is variable in accordance with a thickness of at least one of the plurality of radially-expandable circumferential members varying in the range of from about 0.0015 to about 0.0045 inches. 
   
   
       29 . The stent defined in  claim 22 , further comprising a medicinal coating disposed thereon. 
   
   
       30 . A stent system comprising a balloon catheter having an expandable portion, the expandable portion having disposed thereon the stent defined in  claim 22 . 
   
   
       31 . The stent defined in  claim 23 , wherein said multiple flexure members within the same longitudinal member have substantially the same shape and differing size. 
   
   
       32 . The stent defined in  claim 23 , wherein said multiple flexure members within the same longitudinal member have differing shape and size. 
   
   
       33 . The stent defined in  claim 22 , wherein the porous, cylindrical surface comprises a repeating pattern comprised of a polygon having a pair of side walls substantially parallel to a stent longitudinal axis, and wherein the flexure members are disposed in each of the side walls. 
   
   
       34 . The stent defined in  claim 22 , wherein the longitudinal members are aligned in a spaced relationship parallel to a stent longitudinal axis. 
   
   
       35 . The stent defined in  claim 22 , wherein the longitudinal members are aligned in an interconnected relationship parallel to a stent longitudinal axis. 
   
   
       36 . The stent defined in  claim 22 , wherein the stent is constructed of stainless steel. 
   
   
       37 . The stent defined in  claim 22 , wherein the stent is constructed of a self-expanding material. 
   
   
       38 . The stent defined in  claim 37 , wherein the self-expanding material comprises nitinol. 
   
   
       39 . The stent defined in  claim 37 , wherein the self-expanding material expands at a temperature of greater than about 30° C. 
   
   
       40 . The stent defined in  claim 22 , wherein said flexure members, in two dimensions, having a width less than a width of said undulating circumferential members. 
   
   
       41 . The stent defined in  claim 22 , wherein adjacent undulating circumferential members have substantially the same profile. 
   
   
       42 . The stent defined in  claim 22 , wherein adjacent undulating circumferential members have substantially different profiles. 
   
   
       43 . An expandable stent comprising:
 a series of undulating circumferential portions;   a plurality of longitudinal portions connecting said series of undulating circumferential portions to form a porous, cylindrical surface; and   flexure structure that confers lateral flexibility to said unexpanded stent, said flexure structure being located within said plurality of longitudinal portions, said plurality of longitudinal portions being arranged around said cylindrical surface such that the flexure structures in adjacent longitudinal portions are located at different distances from said circumferential portions, and wherein the flexure structures of adjacent longitudinal portions have different shapes.   
   
   
       44 . The stent of  claim 43 , wherein one or more of said plurality of longitudinal portions includes multiple flexure structures within the same longitudinal portion. 
   
   
       45 . The stent of  claim 44 , wherein said multiple flexure structures within the same longitudinal portion have a same shape. 
   
   
       46 . The stent of  claim 44 , wherein said multiple flexure structures within the same longitudinal portion have a different shape. 
   
   
       47 . The stent of  claim 44 , wherein said multiple flexure structures within the same longitudinal portion have a first lateral section and a second lateral section, and wherein the first lateral section and the second lateral are present on the same side of the longitudinal portion. 
   
   
       48 . The stent of  claim 44 , wherein said multiple flexure structures within the same longitudinal portion have a first lateral section and a second lateral section, and wherein the first lateral section and the second lateral section are present on different sides of the longitudinal portion. 
   
   
       49 . The stent defined in  claim 43 , wherein a relative flexibility of the stent is variable in accordance with a thickness of at least one of the plurality of radially-expandable circumferential struts varying in the range of from about 0.0015 to about 0.0045 inches. 
   
   
       50 . The stent defined in  claim 43 , further comprising a medicinal coating disposed thereon. 
   
   
       51 . A stent system comprising a balloon catheter having an expandable portion, the expandable portion having disposed thereon the stent defined in  claim 43 . 
   
   
       52 . The stent defined in  claim 44 , wherein said multiple flexure structures within the same longitudinal portion have substantially the same shape and differing size. 
   
   
       53 . The stent defined in  claim 44 , wherein said multiple flexure structures within the same longitudinal portion have differing shape and size. 
   
   
       54 . The stent defined in  claim 43 , wherein the porous, cylindrical surface comprises a repeating pattern comprised of a polygon having a pair of side walls substantially parallel to a stent longitudinal axis, and wherein the flexure structures are disposed in each of the side walls. 
   
   
       55 . The stent defined in  claim 43 , wherein the longitudinal portions are aligned in a spaced relationship parallel to a stent longitudinal axis. 
   
   
       56 . The stent defined in  claim 43 , wherein the longitudinal portions are aligned in an interconnected relationship parallel to a stent longitudinal axis. 
   
   
       57 . The stent defined in  claim 43 , wherein the stent is constructed of stainless steel. 
   
   
       58 . The stent defined in  claim 43 , wherein the stent is constructed of a self-expanding material. 
   
   
       59 . The stent defined in  claim 43 , wherein the self-expanding material comprises nitinol. 
   
   
       60 . The stent defined in  claim 43 , wherein the self-expanding material expands at a temperature of greater than about 30° C. 
   
   
       61 . The stent defined in  claim 43 , wherein said flexure structure, in two dimensions, has a width less than a width of said undulating circumferential portions. 
   
   
       62 . The stent defined in  claim 43 , wherein adjacent undulating circumferential portions have substantially the same profile. 
   
   
       63 . The stent defined in  claim 43 , wherein adjacent undulating circumferential portions have substantially different profiles.