Apparatus and methods for delivery of multiple distributed stents

Abstract

Blood vessels and other body lumens are stented using multiple, discreet stent structures. Stent structures may be balloon expandable or self-expanding and are delivered by a delivery catheter which is repositioned to spaced-apart delivery sights. By coating the stents with particular biologically active substances, hyperplasia within and between the implanted stents can be inhibited. An exemplary delivery catheter comprises a catheter body having both a pusher rod for advancing the stents relative to a sheath and a reciprocatable delivery catheter for implanting the stents.

What is claimed is:  
     
         1 . A method for stenting extended lengths of a body lumen, said method comprising: 
 introducing a catheter carrying a plurality of radially expansible prostheses to a target site within said body lumen, wherein said prostheses are arranged end-to-end and covered by a sheath;    retracting the sheath by a first preselected distance to uncover a first predetermined number of the prostheses; and    said first predetermined number of uncovered prostheses radially expanding at a first location within said target site.    
     
     
         2 . A method as in  claim 1 , further comprising inflating a balloon within said prostheses to effect expansion.  
     
     
         3 . A method as in  claim 2 , wherein inflating comprises inflating a balloon disposed both under said prostheses to be expanded and under at least some prostheses which remain under the sheath, wherein inflation of the balloon under the sheath is constrained by the sheath to prevent expansion of the at least some prostheses.  
     
     
         4 . A method as in  claim 2 , further comprising engaging a proximal end of the plurality of prostheses with a pusher tube to axially restrain the prostheses as the sheath is retracted.  
     
     
         5 . A method as in  claim 4 , further comprising engaging a distal end of one of the prostheses with a valve member coupled with the distal end of the sheath.  
     
     
         6 . A method as in  claim 5 , further including retracting the sheath and the pusher tube to separate prostheses proximal to valve from the first predetermined number of prostheses.  
     
     
         7 . A method as in  claim 6 , wherein inflating comprises inflating a balloon disposed under said first predetermined number of prostheses.  
     
     
         8 . A method as in  claim 1 , further comprising heating the uncovered prostheses to effect expansion.  
     
     
         9 . A method as in  claim 8 , wherein heating comprises directing a heated medium through the catheter to the uncovered prostheses.  
     
     
         10 . A method as in  claim 8 , wherein heating comprises energizing a heating element positioned adjacent to the uncovered prostheses.  
     
     
         11 . A method as in  claim 8 , further comprising engaging a proximal end of the plurality of prostheses with a pusher tube to axially restrain the prostheses as the sheath is retracted.  
     
     
         12 . A method as in  claim 1 , wherein said prostheses are resilient and radially constrained within the sheath, wherein the prostheses radially expand as the sheath is retracted.  
     
     
         13 . A method as in  claim 12 , further comprising engaging a proximal end of the plurality of prostheses with a pusher tube to axially restrain the prostheses as the sheath is retracted.  
     
     
         14 . A method as in  claim 1 , further comprising repositioning the catheter and further retracting the sheath by a second preselected distance to uncover a second predetermined number of prostheses, said second predetermined number of uncovered prostheses radially expanding at a second location within said target site.  
     
     
         15 . A method as in  claim 1 , wherein the body lumen is a blood vessel.  
     
     
         16 . A method as in  claim 1 , wherein the prostheses are covered with at least one agent.  
     
     
         17 . A method as in  claim 16 , wherein the agent inhibits hyperplasia.  
     
     
         18 . A method as in  claim 17 , wherein the agent is biologically active.  
     
     
         19 . A method as in  claim 18 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs such as paclitaxel, methotrexate, and batimastal; antibiotics such as doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants such as dexamethasone and methyl prednisolone; nitric oxide sources such as nitroprussides; estrogen; and estradiols.  
     
     
         20 . A method as in  claim 17 , wherein the agent is biologically inert.  
     
     
         21 . A method as in  claim 20 , wherein the biologically inert agent is selected from the group consisting of collagen, polyethylene glycol (PEG), polyglycolic acids (PGA), ceramic material, platinum and gold.  
     
     
         22 . A method for stenting extended lengths of a body lumen, said method comprising: 
 introducing a catheter carrying at least three discrete stents;    releasing at least a first stent from the catheter at a first location in the body lumen;    repositioning the catheter;    releasing at least a second stent from the catheter at a second location;    repositioning the catheter;    releasing at least a third stent from the catheter at a third location.    
     
     
         23 . A method as in  claim 22 , wherein the catheter carries at least four discrete stents, further comprising repositioning the catheter and releasing at least a fourth stent at a fourth location.  
     
     
         24 . A method as in  claim 23 , wherein the catheter carries at least five discrete stents, further comprising repositioning the catheter and releasing at least a fifth stent at a fifth location.  
     
     
         25 . A method as in  claim 22 , wherein the body lumen comprises a blood vessel.  
     
     
         26 . A method as in  claim 25 , wherein the stents are released at locations which span a length of at least 3 mm in the blood vessel.  
     
     
         27 . A method as in  claim 25 , where at least two stents are positioned on opposite sides of an opening in the blood vessel to a side branch.  
     
     
         28 . A method as in  claim 22 , wherein releasing the stents comprises expanding a balloon within the stents.  
     
     
         29 . A method as in  claim 22 , wherein releasing the stents comprises releasing the stents from constraint and allowing the stents to self-expand.  
     
     
         30 . A method as in  claim 22 , wherein the stents are coated with at least one agent.  
     
     
         31 . A method as in  claim 30 , wherein the agent inhibits hyperplasia.  
     
     
         32 . A method as in  claim 30 , wherein the agent is biologically active.  
     
     
         33 . A method as in  claim 32 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs such as paclitaxel, methotrexate, and batimastal; antibiotics such as doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants such as dexamethasone and methyl prednisolone; nitric oxide sources such as nitroprussides; estrogen; and estradiols.  
     
     
         34 . A method as in  claim 30 , wherein the agent is biologically inert.  
     
     
         35 . A method as in  claim 34 , the biologically inert agent is selected from the group consisting of collagen, PEG, PGA, ceramic material, platinum and gold.  
     
     
         36 . A catheter for stenting extended lengths of a body lumen, said catheter comprising: 
 a catheter body having a proximal end and a distal end;    at least three discrete stents carried near a distal end of the catheter body; and    means for deploying the stents independently or in groups from the catheter body within the body.    
     
     
         37 . A catheter as in  claim 36 , comprising at least four discrete stents carried near the distal end of the catheter body.  
     
     
         38 . A catheter as in  claim 37 , comprising at least five discrete stents carried near the distal end of the catheter body.  
     
     
         39 . A catheter as in  claim 36 , wherein the deploying means comprises at least three independently inflatable balloons, wherein each balloon carries at least one stent.  
     
     
         40 . A catheter as in  claim 36 , wherein the deploying means comprises a single balloon reciprocatably mounted within the catheter body and a pusher for successively loading stents over the balloon.  
     
     
         41 . A catheter as in  claim 36 , wherein the deploying means comprises a radial restraint which holds the stents in a radially collapsed configuration and which can be selectively retracted to release the stents independently or in groups.  
     
     
         42 . A catheter as in  claim 36 , wherein the deploying means comprises a radial restraint which holds the stents in a radially collapsed configuration and a pusher for holding the stents in place while the radial restraint is retracted to expose the stents from the distal end of the catheter body independently or in groups.  
     
     
         43 . A catheter as in  claim 42 , wherein the radial restraint comprises a sheath having a valve member at its distal end for engaging a distal end of a proximal stent, to separate the proximal stent from a distal stent.  
     
     
         44 . A catheter as in  claim 36 , wherein the stents are coated with at least one agent.  
     
     
         45 . A catheter as in  claim 44 , wherein the agent inhibits hyperplasia.  
     
     
         46 . A catheter as in  claim 45 , wherein the agent is biologically active.  
     
     
         47 . A catheter as in  claim 46 , wherein the biologically active agent is selected from the group consisting of anti-neoplastic drugs such as paclitaxel, methotrexate, and batimastal; antibiotics such as doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants such as dexamethasone and methyl prednisolone; nitric oxide sources such as nitroprussides; estrogen; and estradiols.  
     
     
         48 . A catheter as in  claim 45 , wherein the agent is biologically inert.  
     
     
         49 . A catheter as in  claim 48 , wherein the biologically inert agent is selected from the group consisting of collagen, PEG, PGA, ceramic material, platinum and gold.  
     
     
         50 . A catheter as in  claim 36 , wherein the stents are composed at least partly of a bioabsorbable material.  
     
     
         51 . A catheter as in  claim 50 , wherein a bioactive substance is disposed in the bioabsorbable material and is released over time as the material degrades.  
     
     
         52 . A catheter as in  claim 50  or  51 , wherein the bioabsorbable material is formed on or within a scaffold composed of a non-bioabsorbable material.  
     
     
         53 . A catheter for delivering a plurality of expansible prostheses to a body lumen, said catheter comprising: 
 a catheter body having a proximal end and a distal end;    a sheath coaxially disposed over the catheter-body; and    a plurality of radially expansible prostheses disposed over a distal portion of the catheter all within the sheath,    wherein the sheath may be retracted proximally, relative to the catheter body and the prostheses, to expose the prostheses beyond a distal end of the sheath.    
     
     
         54 . A catheter as in  claim 53 , further comprising a pusher tube disposed coaxially over the catheter body, within the sheath, and proximal to the prostheses, wherein the pusher tube engages a proximal end of a proximal-most prosthesis so that the pusher tube can be held in place to expose individual prostheses or groups of prostheses as the sheath is retracted proximally.  
     
     
         55 . A catheter as in  claim 54 , wherein at least a distal portion of the sheath has a greater column strength than that of the catheter body.  
     
     
         56 . A catheter as in  claim 54 , wherein at least a distal portion of the pusher tube has a greater column strength than that of the catheter body.  
     
     
         57 . A catheter as in  claim 54 , wherein the pusher tube has at least one of a lubricious inner surface and a lubricious outer surface.  
     
     
         58 . A catheter as in claims  53 - 56 , wherein the prostheses are arranged end-to-end to abut without physical linkage.  
     
     
         59 . A catheter as in claims  53 - 56 , wherein the prostheses are arranged end-to-end with a physical linkage between at least some adjacent pairs of prostheses.  
     
     
         60 . A catheter as in  claim 59 , wherein the physical linkage comprises male and female elements which can be separated without breakage.  
     
     
         61 . A catheter as in  claim 59 , wherein the physical linkage is separated with breakage.  
     
     
         62 . A catheter as in claims  53 - 56 , wherein the catheter body comprises an expansion element near its distal end, said expansion element being positionable distal to the retractable sheath to radially expand one or more of the prostheses.  
     
     
         63 . A catheter as in  claim 62 , wherein the expansion element comprises an inflatable balloon which carries the prostheses, wherein the sheath may be retracted relative to the balloon to expose a preselected number of prostheses and balloon length so that the exposed prostheses and balloon length may be selectively expanded.  
     
     
         64 . A catheter as in  claim 63 , wherein the balloon has a lubricious outer surface.  
     
     
         65 . A catheter as in  claim 63 , further including a valve member at a distal end of the sheath for engaging a distal end of a prosthesis adjacent to a most-proximal prosthesis of the preselected number of prostheses.  
     
     
         66 . A catheter as in  claim 65 , wherein the valve member creates a separation between the distal end of the adjacent prosthesis and the most-proximal prosthesis when the sheath and the pusher are retracted.  
     
     
         67 . A catheter as in claims  53 - 56 , wherein the catheter body includes means for selectively heating prostheses which have been advanced distally beyond the sheath, wherein said prostheses radially expand upon such heating.  
     
     
         68 . A catheter as in  claim 67 , wherein the heating means comprises a lumen within the catheter body for infusing a heated medium to only those prostheses which have been exposed beyond the distal end of the sheath.  
     
     
         69 . A catheter as in  claim 67 , wherein the heating means comprises a heating element disposed on a distal portion of the catheter body and positionable within the prostheses to be expanded.  
     
     
         70 . A catheter as in claims  53 - 56 , wherein the sheath has an outer diameter of 2 mm or less.  
     
     
         71 . A catheter as in  claim 70 , wherein the sheath has an outer diameter of 1 mm or less.  
     
     
         72 . A catheter as in claims  53 - 56 , wherein the sheath has a lubricious outer surface.  
     
     
         73 . A catheter as in claim  53 - 56 , wherein the sheath has a lubricious inner surface.  
     
     
         74 . A catheter as in claim  53 - 56 , wherein the catheter body has at least one of a lubricious inner surface and a lubricious outer surface.  
     
     
         75 . A catheter as in claims  53 - 56 , further comprising means for shearing individual prostheses physically linked with breakable linkages from said plurality of prostheses.  
     
     
         76 . A catheter as in  claim 75 , wherein said severing means comprises a shearing element on a distal region of the catheter body and a mating shearing element on a distal region of the sheath, wherein (1) the catheter body is distally advanced relative to the sheath to permit advancement of one or more prostheses and (2) the catheter body is then proximally retracted relative to the sheath so that the shearing elements shear a breakable linkage.  
     
     
         77 . A catheter for delivering a plurality of expansible prostheses to a body lumen, said catheter comprising: 
 a pusher tube having a proximal end and a distal end;    a plurality of radially expansible prostheses arranged end-to-end and distally of the distal end of the pusher tube;    a sheath disposed coaxially over the pusher tube and the prostheses so that the sheath can be retracted relative to the pusher tube to selectively deploy selective ones of the prostheses.    
     
     
         78 . A catheter as in  claim 77 , further comprising a catheter body having a proximal end and a distal end disposed coaxially within the pusher tube and prostheses.  
     
     
         79 . A catheter as in  claim 77 , wherein at least a distal end of the pusher end of the pusher tube has a greater column strength than the sheath.  
     
     
         80 . A catheter as in  claim 77 , wherein at least a distal portion of the sheath has a greater column strength than that of the catheter body.  
     
     
         81 . A catheter as in  claim 77 , wherein at least a distal portion of the pusher tube has a greater column strength than that of the catheter body.  
     
     
         82 . A catheter as in  claim 77 , wherein the catheter body has at least one of a lubricious outer surface and a lubricious inner surface.  
     
     
         83 . A catheter as in claims  77 - 81 , wherein the sheath has an outer diameter of 2 mm or less.  
     
     
         84 . A catheter as in  claim 83 , wherein the sheath has an outer diameter of 1 mm or less.  
     
     
         85 . A catheter as in claims  77 - 81 , wherein the sheath has a lubricious outer surface.  
     
     
         86 . A catheter as in claims  77 - 81 , wherein the sheath has a lubricious inner surface.  
     
     
         87 . A catheter as in claims  77 - 81 , wherein the pusher tube has at least one of a lubricious inner surface and a lubricious outer surface.  
     
     
         88 . A catheter as in claims  77 - 81 , wherein the prostheses abut each other without physical linkage.  
     
     
         89 . A catheter as in claims  77 - 81 , wherein the prostheses are connected with a physical linkage between at least some adjacent pairs of prostheses.  
     
     
         90 . A catheter as in  claim 89 , wherein the physical linkage comprises male and female elements which can be separated without breakage.  
     
     
         91 . A catheter as in  claim 89 , wherein the physical linkage is separated with breakage.  
     
     
         92 . A catheter as in claims  77 - 81 , wherein the catheter body comprises an expansion element near its distal end, said expansion element being positionable distal to the retractable sheath to radially expand one or more of the prostheses.  
     
     
         93 . A catheter as in  claim 92 , wherein the expansion element comprises an inflatable balloon which carries the prostheses, wherein the sheath may be retracted to expose a preselected number of prostheses and balloon length so that the exposed prostheses and balloon length may be selectively expanded.  
     
     
         94 . A catheter as in claims  77 - 81 , further comprising means for selectively heating prostheses which have been advanced distally beyond the sheath, wherein said prostheses radially expand upon such heating.  
     
     
         95 . A catheter as in  claim 94 , wherein the heating means comprises a lumen within the catheter for infusing a heated medium to only those prostheses which have been distally advanced.  
     
     
         96 . A catheter as in  claim 94 , wherein the heating means comprises a heating element disposed on a distal portion of the catheter and positionable within.  
     
     
         97 . A catheter as in claims  77 - 81 , further comprising means for shearing individual prostheses physically linked with breakable linkages from said plurality of prostheses.  
     
     
         98 . A catheter as in  claim 97 , wherein said severing means comprises a shearing element on a distal region of the catheter and a mating shearing element on a distal region of the sheath, wherein (1) the catheter body is distally advanced relative to the sheath to permit advancement of one or more prostheses and (2) the catheter is then proximally retracted relative to the sheath so that the shearing elements shear a breakable linkage.  
     
     
         99 . A system of detachable expansible prostheses, said system comprising: 
 a plurality of ring-like radially expansible prostheses arranged end-to-end along an elongate axis; and    at least one pair of coupling elements joining each two adjacent prostheses, wherein the coupling elements physically separate without fracture in response to axial tension or differential radial expansion but remain coupled in response to axial compression.    
     
     
         100 . A system as in  claim 99 , wherein the prostheses are composed of a malleable material so that they are expansible in response to an internally applied radially expansive force.  
     
     
         101 . A system as in  claim 99 , wherein the prostheses are composed of a resilient material so that they may be released from radial constraint to self-expand.  
     
     
         102 . A system as in  claim 99 , wherein the prostheses are composed of a material which expands in response to a change in temperature.  
     
     
         103 . A system as in claims  99 - 102 , wherein the coupling elements are male and female so that they decouple by axial withdrawal.  
     
     
         104 . A system as in claims  99 - 102 , wherein the coupling elements are peripherally match patterns which decouple when one of the adjacent prostheses is radially expanded.  
     
     
         105 . A system as in claims  99 - 102 , wherein the prostheses are coated with am agent.  
     
     
         106 . A system as in  claim 105 , wherein the agent inhibits hyperplasia.  
     
     
         107 . A system as in  claim 106 , wherein the agent is biologically active.  
     
     
         108 . A system as in  claim 107 , wherein the biologically active agent is selected from anti-neoplastic drugs such as paclitaxel, methotrexate, and batimastal; antibiotics such as doxycycline, tetracycline, rapamycin, and actinomycin; immunosuppressants such as dexamethasone and methyl prednisolone; nitric oxide sources such as nitroprussides; estrogen; and estradiols.  
     
     
         109 . A system as in  claim 106 , wherein the agent is biologically inert.  
     
     
         110 . A system as in  claim 109 , collagen, PEG, PGA, ceramic material, platinum and gold.  
     
     
         111 . A system as in claims  99 - 102 , in combination with a delivery catheter.  
     
     
         112 . A system as in  claim 111 , wherein the delivery catheter comprises a sheath which is coaxially positioned over the plurality of ring-like prostheses.  
     
     
         113 . A system as in  claim 112 , wherein the delivery catheter further comprises a pusher tube for selectively advancing one or more prostheses from the sheath.  
     
     
         114 . A system as in  claim 113 , wherein the delivery catheter further comprises means for radially expanding the prosthesis after said prosthesis has been advanced from the sheath.  
     
     
         115 . A system as in  claim 114 , wherein the means for expanding comprises an inflatable balloon.  
     
     
         116 . A system as in  claim 114 , wherein the means for expanding comprises a heater for heating a temperature-response prostheses.