Fixed stent delivery devices and methods

Abstract

Stent delivery devices and methods include multiple stents or stent segments mounted at fixed positions on an expandable member of the stent delivery catheter. One or more of the fixed-position stents may be selectively deployed in a body lumen such as a blood vessel by positioning one or more sheaths to constrain some stents while exposing others for deployment. Some embodiments include two axially movable sheaths for serially deploying stents while containing a portion of the expandable balloon from which stents have been deployed. Other embodiments include inner and outer balloon shafts to allow the balloon to be retracted into the delivery catheter as stents are deployed. Devices and methods of the invention provide enhanced serial deployment of multiple stents or stent segments while reducing the risk of damage to an expandable deployment member.

1 . A stent delivery device for delivering a plurality of stent segments to a treatment site, the device comprising:
 a catheter shaft having a proximal end and a distal end;   an expandable member coupled with the catheter shaft near the distal end;   a plurality of stent segments mounted on the expandable member; and   at least a first axially movable sheath disposed over at least part of the catheter shaft, the expandable member and the stent segments, wherein the first sheath is adapted to constrain expansion of a first portion of the expandable member and stent segments thereon while allowing expansion of a second portion of the expandable member and stent segments thereon.   
   
   
       2 . A device as in  claim 1 , wherein each of the plurality of stent segments is spaced apart from adjacent stent segments, so that each stent segment can be expanded by the expandable member without interfering with adjacent stent segments. 
   
   
       3 . A device as in  claim 1 , further including at least a second axially movable sheath disposed over part of the catheter shaft, the expandable member and the stent segments, wherein the first sheath is disposed proximally along the catheter shaft relative to the second sheath, and wherein the first and second sheaths are adapted to allow expansion and deployment of at least one stent segment between the sheaths. 
   
   
       4 . A device as in  claim 3 , wherein the second sheath is movable distally to allow for deployment of at least one stent segment and proximally to constrain a portion of the expandable member from which at least one stent segment has been deployed. 
   
   
       5 . A device as in  claim 1 , further including an inner shaft slidably disposed within the catheter shaft, the expandable member having a distal end coupled with the inner shaft for retracting relative to the catheter shaft a portion of the expandable member from which at least one stent segment has been deployed. 
   
   
       6 . A stent delivery device for delivering a plurality of stent segments to a treatment site, the device comprising:
 a catheter shaft having a proximal end and a distal end;   an expandable member coupled with the catheter shaft near the distal end;   a plurality of stent segments mounted at fixed positions on the expandable member;   at least one axially movable sheath disposed over at least part of the catheter shaft, the expandable member and the stent segments, wherein the sheath is adapted to constrain expansion of a first portion of the expandable member and stent segments thereon while allowing expansion of a second portion of the expandable member and stent segments thereon; and   an inner shaft slidably disposed within the catheter shaft,   wherein the expandable member includes a distal end coupled with the inner shaft for retracting relative to the catheter shaft a portion of the expandable member from which at least one stent segment has been deployed.   
   
   
       7 . An interventional catheter device comprising:
 a catheter shaft having a proximal end and a distal end;   an expandable member coupled with the catheter shaft near the distal end;   a distal sheath axially movable relative to the expandable member and positionable over at least a distal portion thereof, and   a proximal sheath axially movable relative to the expandable member and the distal sheath and positionable over at least a proximal portion of the expandable member,   wherein the distal and proximal sheaths are axially positionable to expose a selected portion of the expandable member to allow expansion thereof while covering another portion of the expandable member to constrain expansion thereof.   
   
   
       8 . A device as in  claim 7 , further comprising a plurality of stents mounted on the expandable member. 
   
   
       9 . A device as in  claim 8 , wherein the distal sheath is movable distally to allow for deployment of at least one stent and proximally to constrain a portion of the expandable member from which at least one stent has been deployed. 
   
   
       10 . A device as in  claim 8 , wherein at least a first of the stents has a different characteristic than at least a second of the stents, wherein the first and second stents are mounted at different locations along the expandable member, and wherein the characteristic is selected from the group consisting of diameter, length, shape, geometry, stiffness, stent material, and coating material. 
   
   
       11 . A device as in  claim 7 , wherein the expandable member is tapered along its length, and wherein the distal and proximal sheaths are positionable to expose at least a first portion of the expandable member having a first average cross-sectional diameter while covering at least a second portion of the expandable member having a second average cross-sectional diameter. 
   
   
       12 . A device as in  claim 11 , wherein each of the plurality of stents comprises a plurality of stent segments. 
   
   
       13 . A device as in  claim 12 , wherein the length of each stent may be selected by selecting the number of stent segments. 
   
   
       14 . A device as in  claim 7 , wherein the expandable member includes a first tapered portion having a first average cross-sectional diameter and a second tapered portion having a second average cross-sectional diameter, and wherein the distal and proximal sheaths are positionable to expose the first portion while covering the second portion. 
   
   
       15 . A stent delivery device for delivering a plurality of stent segments to a treatment site, the device comprising:
 a catheter shaft having a proximal end and a distal end;   a plurality of self-expanding stent segments disposed on the catheter shaft;   a distal sheath axially movable relative to the stent segments and positionable over at least one distal segment; and   a proximal sheath axially movable relative to the stent segments and the distal sheath and positionable over at least one proximal segment,   wherein the distal and proximal sheaths are axially positionable to expose one or more selected stent segments to allow expansion thereof while covering one or more other stent segments to constrain expansion thereof.