Multiple independent nested stent structures and methods for their preparation and deployment

Abstract

Blood vessels and other body lumens are stented using stent structures comprising a plurality of radially expansible rings where at least some of the rings comprise axially extending elements which interleave with axially extending elements on adjacent unconnected rings. The ring structures may be open cell structures or closed cell structures, and the axially extending elements will typically be formed as part of the open cell or closed cell structure.

1 . A prosthesis comprising:
 a plurality of rings axially arranged, the rings radially expandable from a contracted configuration to an expanded configuration, wherein in the expanded configuration the rings are suitable for supporting a wall of a lumen, and   wherein at least some of the rings comprise axially extending elements which interleave with axially extending elements on an adjacent ring when the rings are in the contracted configuration and the expanded configuration without interlocking the adjacent rings thereby allowing axial separation of the adjacent rings.   
   
   
       2 . A prosthesis according to  claim 1 , wherein the axially extending elements interleave over a distance of at least 0.1 mm while the rings are in the contracted configuration. 
   
   
       3 . A prosthesis according to  claim 1 , wherein the axially extending elements interleave over a distance in the range from 1 mm to 5 mm while the rings are in the contracted configuration. 
   
   
       4 . A prosthesis according to  claim 1 , wherein the axially extending elements interleave over a distance in the range from about 0.1 mm to 0.5 mm while the rings are in the expanded configuration. 
   
   
       5 . A prosthesis according to  claim 1 , wherein the rings releasably carry a biologically active agent. 
   
   
       6 . A prosthesis according to  claim 5 , wherein the biologically active agent inhibits restenosis. 
   
   
       7 . A prosthesis according to  claim 1 , wherein the rings comprise a plurality of closed cell structures. 
   
   
       8 . A prosthesis according to  claim 1 , wherein the rings comprise a plurality of open cell structures. 
   
   
       9 . A prosthesis according to  claim 1 , wherein at least some of the axially extending elements comprise expansible open structures. 
   
   
       10 . A prosthesis according to  claim 9 , wherein the expansible open structures are selected from the group consisting of serpentine, zigzag and castellated structures. 
   
   
       11 . A prosthesis according to  claim 1 , wherein the rings have axial lengths in the range from 1 mm to 10 mm prior to radial expansion. 
   
   
       12 . A prosthesis according to  claim 1 , wherein the plurality of rings consists of from 2 to 50 rings. 
   
   
       13 . A prosthesis according to  claim 1 , wherein overall prosthesis length is in the range from 2 mm to 200 mm. 
   
   
       14 . A prosthesis according to  claim 1 , wherein the rings are balloon expandable. 
   
   
       15 . A prosthesis according to  claim 1 , further comprising at least one radiopaque marker coupled with at least one of the rings. 
   
   
       16 . A method for delivering a prosthesis to a treatment site in a body lumen, said method comprising:
 advancing a delivery catheter to the treatment site, the delivery catheter carrying a plurality of separable rings near a distal end thereof, the rings axially arranged thereover,   wherein at least some of the rings comprise axially extending elements which interleave with axially extending elements on an adjacent separable ring when the rings are in the contracted configuration without interlocking the adjacent separable rings thereby allowing axial movement therebetween;   selecting a number of the plurality of rings for deployment; and   radially expanding the selected number of rings from the contracted configuration to an expanded configuration, wherein in the expanded configuration the rings support a wall of the lumen and axially extending elements interleave between at least some of the selected number of rings without interlocking the selected number of rings thereby allowing axial movement therebetween.   
   
   
       17 . A method according to  claim 16 , wherein the axially extending elements interleave over a distance of at least 0.1 mm while the segments are in the contracted configuration. 
   
   
       18 . A method according to  claim 16 , wherein the axially extending elements interleave over a distance in the range from 1 mm to 5 mm while the segments are in the contracted configuration. 
   
   
       19 . A method according to  claim 16 , wherein the axially extending elements interleave over a distance in the range from about 0.1 mm to 0.5 mm while the segments are in the expanded configuration. 
   
   
       20 . A method according to  claim 16 , further comprising releasing a biologically active agent carried by the segments. 
   
   
       21 . A method according to  claim 20 , wherein the agent inhibits restenosis. 
   
   
       22 . A method according to  claim 16 , wherein the body lumen is a blood vessel. 
   
   
       23 . A method according to  claim 16 , wherein radially expanding comprises inflating a balloon disposed near the distal end of the delivery catheter. 
   
   
       24 . A method according to  claim 16 , wherein radially expanding comprises simultaneously expanding the selected number of rings. 
   
   
       25 . A method according to  claim 16 , wherein the plurality of rings consists of from 2 to 50 rings. 
   
   
       26 . A method according to  claim 16 , wherein the wherein the rings have axial lengths in the range from 1 mm to 10 mm prior to radial expansion. 
   
   
       27 . A method according to  claim 16 , wherein overall prosthesis length is in the range from 2 mm to 200 mm. 
   
   
       28 . A method according to  claim 16 , wherein adjacent rings are axially separable from one another in the contracted configuration. 
   
   
       29 . A method according to  claim 16 , wherein the rings comprise a plurality of closed cell structures. 
   
   
       30 . A method according to  claim 16 , wherein the rings comprise a plurality of open cell structures. 
   
   
       31 . A method according to  claim 16 , wherein at least some of the axially extending elements comprise expansible open structures. 
   
   
       32 . A method according to  claim 31 , wherein the expansible open structures are selected from the group consisting of serpentine, zigzag and castellated structures.