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.

What is claimed is:  
     
         1 . A stent structure comprising: 
 a plurality of radially expansible rings arranged along an axial line, wherein at least some of the axially adjacent rings are not connected and wherein at least some of the axially unconnected rings comprise axially extending elements which interleave with axially extending elements on an adjacent unconnected ring without interlocking with the adjacent unconnected ring.    
     
     
         2 . A stent structure as in  claim 1 , wherein at least some of the axially extending elements comprise expansible closed structures which open as the rings are expanded.  
     
     
         3 . A stent structure as in  claim 2 , wherein the expansible closed structures are selected from the group consisting of boxes, diamonds, rhomboids, ovals, and ellipses.  
     
     
         4 . A stent structure as in  claim 2 , wherein the closed cells are defined by a slot pattern selected from the group consisting of I-patterns, H-patterns, and J-patterns.  
     
     
         5 . A stent structure as in  claim 1 , wherein at least some of the axially extending elements comprise expansible open structures.  
     
     
         6 . A stent structure as in  claim 5 , wherein the expansible open structures are selected from the group consisting of serpentine structures, zigzag structures, and castellated structures.  
     
     
         7 . A stent structure as in  claim 1 , wherein at least some of the axially unconnected rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.  
     
     
         8 . A stent structure as in  claim 1 , wherein the axially unconnected rings are configured to axially shorten upon expansion.  
     
     
         9 . A stent structure as in  claim 1 , wherein the axially extending elements remain interleaved following expansion.  
     
     
         10 . A stent structure as in  claim 1 , wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.  
     
     
         11 . A stent structure as in  claim 10 , wherein the distance is in the range from 1 mm to 5 mm.  
     
     
         12 . A stent structure as in  claim 1 , wherein the rings have axial lengths in range from 1 mm to 10 mm, prior to radial expansion.  
     
     
         13 . A stent structure as in  claim 1 , consisting of from two to 50 expansible ring structures.  
     
     
         14 . A stent structure as in  claim 1 , wherein the radially expansible rings releasably carry a biologically active agent.  
     
     
         15 . A stent structure as in  claim 14 , wherein the biologically active agent inhibits hyperplasia.  
     
     
         16 . A stent structure as in  claim 15 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs, including paclitaxel, methotrexate, and batimastal; antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants including dexamethasone, and methyl prednisolone; nitric oxide sources including nitroprussides; estrogen; and estradiols.  
     
     
         17 . A stent deployment system comprising: 
 an elongated carrier having a central axis;    a plurality of radially expansible rings arranged over a surface of the elongated carrier, wherein at least some of the radially expansible rings comprise axially extending elements which interleave with axially extending elements on an adjacent unconnected ring without interlocking with the adjacent radially expansible ring.    
     
     
         18 . A stent deployment system as in  claim 17 , wherein the elongated carrier comprises a radially expansible balloon having an outer surface, wherein the radially expansible rings are disposed over the outer surface of the balloon.  
     
     
         19 . A stent deployment system as in  claim 18 , wherein the balloon consists of a single inflation chamber.  
     
     
         20 . A stent deployment system as in  claim 18 , wherein the balloon comprises a plurality of independent chambers wherein individual expansible rings are disposed over single independently inflatable chambers.  
     
     
         21 . A stent deployment system as in  claim 17 , wherein the elongated carrier comprises a carrier tube having an inner surface which constrains the radially expansible rings.  
     
     
         22 . A stent deployment system as in  claim 21 , further comprising a pusher tube arranged to axially advance the radially expansible rings from the carrier tube.  
     
     
         23 . A stent deployment system as in  claim 22 , wherein the radially expansible rings are resilient and radially constrained so that they expand when advanced distally from the carrier tube.  
     
     
         24 . A stent deployment system as in  claim 17 , wherein the radially expansible rings are deformable, said structure further comprising a balloon arranged to expand individual rings as said rings are advanced from the carrier tube.  
     
     
         25 . A stent deployment system as in  claim 17 , wherein at least some of the axially expanding elements comprise expansible closed structures.  
     
     
         26 . A stent deployment system as in  claim 25 , wherein the expansible closed structures are selected from the group consisting of boxes, rhomboids, ovals, ellipses, diamonds, and irregular polygons.  
     
     
         27 . A stent deployment structure as in  claim 25 , wherein the closed cells are defined by a slot pattern selected from the group consisting of I-patterns and H-patterns.  
     
     
         28 . A stent deployment structure as in  claim 17 , wherein at least some of the axially unconnected rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.  
     
     
         29 . A stent deployment system as in  claim 17 , wherein at least some of the axially extending elements comprise expansible open structures.  
     
     
         30 . A stent deployment system as in  claim 29 , wherein the expansible open structures are selected from the group consisting of expansible structures, zigzag structures, and castellated structures.  
     
     
         31 . A stent deployment structure as in  claim 17 , wherein the radially expansible rings are configured to axially shorten upon expansion.  
     
     
         32 . A stent deployment structure as in  claim 17 , wherein the axially extending elements remain interleaved following expansion.  
     
     
         33 . A stent deployment structure as in  claim 17 , wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.  
     
     
         34 . A stent deployment structure as in  claim 33 , wherein the distance is in the range from 1 mm to 5 mm.  
     
     
         35 . A stent deployment system as in  claim 17 , wherein the rings have axial lengths in range from 11 mm to 10 mm, prior to radial expansion.  
     
     
         36 . A stent deployment system as in  claim 35 , consisting of from two to 50 expansible ring structures.  
     
     
         37 . A stent deployment system as in  claim 17 , wherein the radially expansible rings releasably carry a biologically active agent.  
     
     
         38 . A stent deployment system as in  claim 37 , wherein the biologically active agent inhibits hyperplasia.  
     
     
         39 . A stent deployment system as in  claim 38 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs including paclitaxel, methotrexate, and batimastal; antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants including dexamethasone and methyl prednisolone; nitric oxide sources including nitroprussides; estrogen; and estradiols.  
     
     
         40 . A method for arranging multiple independent stent rings on a carrier of a catheter, said method comprising: 
 providing an elongated carrier structure;    mounting a plurality of radially expansible rings comprising axially extending elements on the carrier structure, wherein the axially extending elements on adjacent rings interleave when mounted on the carrier structure without interlocking.    
     
     
         41 . A method as in  claim 40 , wherein the number of rings mounted on the carrier structure is selected to provide a desired overall stent length.  
     
     
         42 . A method as in  claim 41 , wherein the number of rings is from two to 50 and the overall stent length is in the range from 2 mm to 200 mm.  
     
     
         43 . A method as in  claim 40 , wherein at least some of the axially extending elements comprise expansible closed structures.  
     
     
         44 . A method as in  claim 43 , wherein the expansible closed structures are selected from the group consisting of boxes, rhomboids, ovals, ellipses, diamonds, and irregular polygons.  
     
     
         45 . A method as in  claim 43 , wherein the expansible closed structures are defined by a slot pattern selected from the group consisting of I-patterns and H-patterns, and J-patterns.  
     
     
         46 . A method as in  claim 40 , wherein at least some of the axially extending elements comprise expansible open structures.  
     
     
         47 . A method as in  claim 46 , wherein the expansible open structures are selected from the group consisting of serpentine structures, zigzag structures, and castellated structures.  
     
     
         48 . A method as in  claim 40 , wherein at least some of the axially unconnected rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.  
     
     
         49 . A method as in  claim 40 , wherein the radially expansible rings are configured to axially shorten upon expansion.  
     
     
         50 . A method as in  claim 40 , wherein the axially extending elements remain interleaved following expansion.  
     
     
         51 . A method as in  claim 40 , wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.  
     
     
         52 . A method as in  claim 51 , wherein the distance is in the range from 1 mm to 5 mm.  
     
     
         53 . A method as in  claim 40 , wherein the rings have axial lengths in range from 1 mm to 10 mm, prior to radial expansion.  
     
     
         54 . A method as in  claim 53 , wherein the rings have axial lengths in the range from 0.9 mm to 9 mm after radial expansion.  
     
     
         55 . A method as in  claim 54 , consisting of from two to 50 expansible ring structures.  
     
     
         56 . A method as in  claim 40 , wherein the radially expansible rings releasably carry a biologically active agent.  
     
     
         57 . A method as in  claim 56 , wherein the biologically active agent inhibits hyperplasia.  
     
     
         58 . A method as in  claim 57 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs including paclitaxel, methotrexate and batimastal; antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants including dexamethasone and methyl prednisolone; nitric oxide sources including nitroprussides; estrogen; and estradiols.  
     
     
         59 . A method for stenting a body lumen, said method comprising: 
 delivering to the body lumen a stent structure having a plurality of radially expansible rings arranged along an axial line, wherein at least some of the axially adjacent rings are not connected and wherein at least some of the axially unconnected rings comprise axially extending elements which interleave with axially extending elements on an adjacent unconnected ring without interlocking with the adjacent unconnected ring; and    expanding at least some of the rings within the body lumen so that the axially extending elements open and axially move apart from each other.    
     
     
         60 . A method as in  claim 59 , wherein the body lumen is a blood vessel.  
     
     
         61 . A method as in  claim 60 , wherein the blood vessel is an artery.  
     
     
         62 . A method as in  claim 59 , wherein two to 50 rings are delivered over a luminal length in the range from 2 mm to 200 mm.  
     
     
         63 . A method as in  claim 59 , wherein at least some of the axially extending elements comprise expansible closed structures which circumferentially expand as the rings are expanded.  
     
     
         64 . A method as in  claim 63 , wherein the expansible closed structures are selected from the group consisting of boxes, rhomboids, ovals, ellipses, diamonds, and irregular polygons.  
     
     
         65 . A method as in  claim 63 , wherein the closed cells are defined by a slot pattern selected from the group consisting of I-patterns, H-patterns, and J-patterns.  
     
     
         66 . A method as in  claim 59 , wherein at least some of the axially extending elements comprise expansible open structures which circumferentially expand as the rings are expanded.  
     
     
         67 . A method as in  claim 66 , wherein the expansible open structures are selected from the group consisting of serpentine structure, zigzag structures, and castellated structures.  
     
     
         68 . A method as in  claim 59 , wherein at least some of the axially unconnected rings further comprise spacers which engage the axially extending elements on adjacent rings to provide a preselected spacing between adjacent rings upon radial expansion.  
     
     
         69 . A method as in  claim 59 , wherein the axially extending elements remain interleaved following expansion.  
     
     
         70 . A method as in  claim 59  wherein the radially expansible rings are configured to axially shorten upon expansion.  
     
     
         71 . A method as in  claim 59 , wherein the axially extending elements axially interleave over a distance of at least 0.1 mm prior to stent expansion.  
     
     
         72 . A method as in  claim 71 , wherein the distance is in the range from 1 mm to 5 mm.  
     
     
         73 . A method as in  claim 59 , wherein the radially expansible rings carry a biologically active agent which is released in the body lumen after the rings are expanded.  
     
     
         74 . A method as in  claim 73 , wherein the biologically active agent inhibits hyperplasia.  
     
     
         75 . A method as in  claim 74 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs including paclitaxel, methotrexate and batimastal; antibiotics including doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants including dexamethasone and methyl prednisolone; 
 nitric oxide sources including nitroprussides; estrogen; and estradiols.    
     
     
         76 . A method as in  claim 59 , wherein the body lumen is curved, and wherein the axially extending members remain interleaved after expansion of the stent is performed.