Methods and apparatus for luminal stenting

Abstract

A stent delivery system, a core assembly, and methods of operating the same are provided. The delivery system can comprise a catheter and the core assembly. The core assembly can comprise a constraining member, sleeve, a core member, and a stent extending along the core member. The tubular constraining member can be spaced apart from the core member and define a capture area. The sleeve can be disposed along the core member at least partially distal of the capture area. The stent can have a first portion disposed within the capture area and a second portion, distal to the first portion, extending across or over an outer surface of the sleeve so that the sleeve and the constraining member cooperate to inhibit expansion of the first portion of the stent.

What is claimed is: 
     
         1 . A stent delivery system, comprising:
 a microcatheter having a distal end configured to be inserted into a blood vessel;   a constraining member extending within the microcatheter and having a distal portion;   a core member extending within the microcatheter, the core member having a distal segment;   at least one sleeve positioned about the core member distal segment and rotatably coupled to the core member; and   a stent extending along the core member distal segment, a proximal end of the stent being engaged with the constraining member distal portion and the sleeve to restrict movement of the stent relative to the constraining member and the sleeve while the core member is rotatable relative to the stent, the constraining member, and the sleeve.   
     
     
         2 . The system of  claim 1 , wherein the core member is rotatable relative to the stent and the microcatheter when a distal end of the stent is expanded into contact with the vessel. 
     
     
         3 . The system of  claim 1 , wherein the microcatheter comprises a lumen having a central axis, and wherein the core member distal segment comprises an arcuate tip that extends transverse to the axis. 
     
     
         4 . The system of  claim 1 , wherein the sleeve is positioned adjacent to the constraining member distal portion along the core member in an engaged position. 
     
     
         5 . The system of  claim 4 , wherein the constraining member has a capture area configured to receive a first portion of the stent, the stent having a second portion, distal to the first portion, supported on an outer surface of the sleeve to restrict movement of the stent relative to the sleeve and the constraining member. 
     
     
         6 . The system of  claim 4 , wherein the constraining member and sleeve cooperate to grip the proximal end of the stent. 
     
     
         7 . The system of  claim 1 , wherein the core member extends within the constraining member. 
     
     
         8 . The system of  claim 1 , further comprising a distal cover extending proximally from the core member distal segment and interposed between an outer surface of the stent and an inner surface of the microcatheter. 
     
     
         9 . The system of  claim 8 , wherein the distal tip is rotatably coupled to the core member. 
     
     
         10 . The system of  claim 9 , wherein the sleeve and distal cover permit rotation of the core member relative to the stent. 
     
     
         11 . The system of  claim 1 , further comprising an actuator attached to a proximal portion of the core member, the actuator being configured to impart rotation the core member. 
     
     
         12 . The system of  claim 1 , wherein the core member comprises a delivery wire. 
     
     
         13 . A method of operating a rotatable stent delivery system, the method comprising:
 advancing a distal end of a catheter in a blood vessel;   advancing the delivery system within the catheter, the delivery system comprising a stent, a constraining member, a core wire having a central longitudinal axis, and a sleeve rotatably coupled about the core wire, the stent extending over the sleeve and being restricted from movement relative to the sleeve and the constraining member, the core wire being rotatable relative to the stent, the sleeve, and the constraining member; and   advancing the core wire distally to guide the delivery system along a path of the vessel.   
     
     
         14 . The method of  claim 13 , wherein advancing the stent comprises moving the stent into apposition with a wall of the blood vessel. 
     
     
         15 . The method of  claim 13 , wherein the core wire comprises a distalmost curvilinear tip that bends away from the axis, and the method further comprises rotating the tip via the core wire relative to the stent, the sleeve, and the constraining member. 
     
     
         16 . The method of  claim 15 , wherein the tip is advanced toward a vessel bifurcation. 
     
     
         17 . The method of  claim 15 , wherein rotating the tip comprises directing the tip in a direction away from an apex of the bifurcation. 
     
     
         18 . A stent delivery system, comprising:
 a microcatheter having a lumen;   a constraining sheath having a distal portion and extending within the microcatheter lumen;   a core member extending within the microcatheter lumen;   at least one sleeve positioned about and rotatably coupled to the core member; and   a self-expanding stent having (i) a first portion disposed within the sheath lumen and (ii) a second portion distal of the first portion and extending over an outer surface of the sleeve, while the core member is rotatable relative to the stent, the constraining member, and the sleeve.   
     
     
         19 . The system of  claim 18 , wherein the sleeve has a cross-sectional outer profile that is sized greater than a cross-sectional inner profile of the constraining sheath lumen. 
     
     
         20 . The system of  claim 18 , wherein the core member extends within a lumen of the constraining sheath. 
     
     
         21 . The system of  claim 18 , wherein in a delivery position, the first portion of the stent is restricted from expansion and restricted from longitudinal movement relative to the sleeve and the sheath distal portion. 
     
     
         22 . The system of  claim 21 , wherein the stent has a first diameter at the first portion and a second diameter at the second portion, sized greater than the first diameter, such that the stent is secured between the sleeve and the sheath distal portion. 
     
     
         23 . The system of  claim 18 , wherein a collective outer profile of the stent and the sleeve is sized greater than the sheath inner profile. 
     
     
         24 . The system of  claim 18 , wherein the constraining sheath distal portion (i) is spaced apart from the core member and (ii) has a capture area. 
     
     
         25 . The system of  claim 24 , wherein an outer surface of the sleeve is radially offset from the capture area.