Close-cell structured stent, a preparation method and use thereof

Abstract

Disclosed herein is a close-cell structured stent which is composed of curved struts that intersect at a crossing angle of 90 to 170 degrees in the longitudinal direction. Methods for making the stent, use of the stent as a vascular stent, an esophagus stent, an intestine stent, a bile conduct stent, or a urinary tract stent, and use of the stent in the manufacture of stent graft for the treatment of abdominal aortic aneurysms are also provided. The stent has both excellent longitudinal flexibility and radial strength.

1 . (canceled) 
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . A stent comprising:
 a plurality of struts coupled together to form a plurality of closed rings, wherein adjacent closed rings are coupled together to form a plurality of closed cells,
 wherein each closed cell comprises a plurality of curved struts coupled together, 
 wherein at least some of the plurality of curved struts intersect one another at an angle from 90 to 170 degrees in a longitudinal direction, 
 wherein at least some of the plurality of curved struts comprise a first curved strut comprising a first curved region, a second curved strut comprising a second curved region, a third curved strut comprising a third curved region, and a fourth curved strut comprising a fourth curved region, and 
 wherein the first curved region, the second curved region, the third curved region, and the fourth curved region deform and guide deformation of the plurality of struts during crimping of a stent into a crimped configuration. 
   
     
     
         5 . The stent of  claim 4 , wherein an inner portion of the first curved region comprises a first concave region facing inward toward a center of a first closed cell,
 wherein an outer portion of the second curved region comprises a second concave region facing outward away from the center of the first closed cell,   wherein an inner portion of the third curved region comprises a third concave region facing inward toward the center of the first closed cell, and   wherein an outer portion of the fourth curved region comprises a fourth concave region facing outward away from the center of the first closed cell.   
     
     
         6 . The stent of  claim 4 , wherein the first curved strut, the second curved strut, the third curved strut, and the fourth curved strut are arranged in a clockwise pattern with the first curved strut following the fourth curved strut, the second curved strut following the first curved strut, the third curved strut following the second curved strut, and the fourth curved strut following the third curved strut. 
     
     
         7 . The stent of  claim 4 , wherein the first curved strut has a first end and a second end, the second curved strut has a first end and a second end, the third curved strut has a first end and a second end, and the fourth strut has a first end and a second end, wherein
 the second end of the first curved strut is coupled to the first end of the second curved strut to form a first turn in the closed cell,   the second end of the second curved strut is coupled to the first of the third curved strut to form second turn in the closed cell,   the second end of the third curved strut is coupled to the first end of the fourth curved strut to form a third turn in the closed cell, and   the second end of the fourth curved strut is coupled to the first end of the first curved strut to form a fourth turn in the closed cell.   
     
     
         8 . The stent of  claim 4 , wherein the first curved strut has an outer portion with a first convex region facing outward away from the center of the first closed cell,
 wherein the second curved strut has an inner portion with a second convex region facing inward toward the center of the first closed cell,   wherein the third curved strut has an outer portion with a third convex region facing outward away from the center of the first closed cell, and   wherein the fourth curved strut has an inner portion with a fourth convex region facing inward toward the center of the first closed cell.   
     
     
         9 . The stent of  claim 4 , wherein the first curved strut is coupled directly to the second curved strut, the second curved strut is coupled directly to the third curved strut, the third curved strut is coupled directly to the fourth curved strut, and the fourth curved strut is coupled directly to the first curved strut. 
     
     
         10 . The stent of  claim 4 , wherein a radial strength of the stent increases when the angle increases. 
     
     
         11 . The stent of  claim 4 , wherein each closed cell has a first dimension in a circumferential direction and a second dimension extending along a longitudinal axis of the stent, and wherein the first dimension is larger than the second dimension when the stent is in an expanded configuration. 
     
     
         12 . The stent of  claim 11 , wherein a curvature of the curved struts is defined by a deviation of the curved struts a distance from the longitudinal axis and wherein the distance is in the range of 0.01 mm to 0.99 mm. 
     
     
         13 . The stent of  claim 4 , wherein the angle is from 140 to 150 degrees. 
     
     
         14 . The stent of  claim 4 , further comprising a therapeutic agent carried by at least some of the plurality of rings. 
     
     
         15 . The stent of  claim 4 , further comprising a coating disposed on at least some of the curved struts. 
     
     
         16 . The stent of  claim 4 , further comprising a fabric coupled to at least some of the curved struts. 
     
     
         17 . A method of manufacturing a stent, the method comprising:
 forming a stent to comprise a plurality of struts, the stent comprising an expanded configuration and a collapsed configuration, wherein in the expanded configuration the plurality of struts are coupled together to form a plurality of closed rings, wherein adjacent closed rings are coupled together to form a plurality of closed cells,   wherein each closed cell comprises four or more curved struts coupled together, and   wherein at least some of the four or more curved struts intersect one another at an angle from 90 to 170 degrees in a longitudinal direction,   wherein at least some of the plurality of curved struts comprise a first curved strut comprising a first curved region, a second curved strut comprising of a second curved region, a third curved strut comprising of a third curved region, and a fourth curved strut comprising of a fourth curved region, and   wherein the first curved region, the second curved region, the third curved region, and the fourth curved region deform and guide deformation of the plurality of struts during crimping of the stent into a crimped configuration.   
     
     
         18 . The method of  claim 17 , further comprising applying a coating to at least some of the four curved struts. 
     
     
         19 . The method of  claim 17 , wherein the four or more curved struts comprise a first curved strut comprising a first curved region, a second curved strut comprising a second curved region, a third curved strut comprising a third curved region, and a fourth curved strut comprising a fourth curved region. 
     
     
         20 . The stent of  claim 19 , wherein the first curved strut has a first end and a second end, the second curved strut has a first end and a second end, the third curved strut has a first end and a second end, and the fourth strut has a first end and a second end, wherein
 the second end of the first curved strut is coupled to the first end of the second curved strut to form a first turn in the closed cell,   the second end of the second curved strut is coupled to the first of the third curved strut to form second turn in the closed cell,   the second end of the third curved strut is coupled to the first end of the fourth curved strut to form a third turn in the closed cell, and   the second end of the fourth curved strut is coupled to the first end of the first curved strut to form a fourth turn in the closed cell.   
     
     
         21 . The stent of  claim 19 , wherein the first curved strut has an outer portion with a first convex region facing outward away from the center of the first closed cell,
 wherein the second curved strut has an inner portion with a second convex region facing inward toward the center of the first closed cell,   wherein the third curved strut has an outer portion with a third convex region facing outward away from the center of the first closed cell, and   wherein the fourth curved strut has an inner portion with a fourth convex region facing inward toward the center of the first closed cell.   
     
     
         22 . The stent of  claim 19 , wherein the first curved strut is coupled directly to the second curved strut, the second curved strut is coupled directly to the third curved strut, the third curved strut is coupled directly to the fourth curved strut, and the fourth curved strut is coupled directly to the first curved strut. 
     
     
         23 . A method of crimping a stent, the method comprising:
 providing a stent comprising a plurality of struts coupled together to form a plurality of closed rings, wherein adjacent closed rings are coupled together to form a plurality of closed cells, and wherein each closed cell comprises a plurality of curved struts coupled together, wherein at least some of the curved struts intersect one another at an angle from 90 to 170 degrees in a longitudinal direction; and   crimping the stent onto a catheter by deforming at least some of the plurality of struts, wherein deforming the at least some of the plurality of struts occurs on a curved region of the curved struts.   
     
     
         24 . The method of  claim 23 , wherein crimping the stent comprises crimping the stent onto an expandable member. 
     
     
         25 . The method of  claim 23 , wherein longitudinal expansion of the stent is minimized during the crimping.