Introducer sheath having frangible tip

• US 20070225659A1
• Filed: 03/19/2007
• Published: 09/27/2007
• Est. Priority Date: 03/21/2006
• Status: Abandoned Application

• Current Assignee: Cook Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated)
• Inventors: Melsheimer, Jeffry S.
• Application Number:
  US11/725,391
• Publication Number:
  US 20070225659A1
• Time in Patent Office: Days
• US Class Current: 604/264
• CPC Class Codes: A61M 25/0668 splittable, tear apart
• CPC Class Codes: A61M 25/104 used for angioplasty

Abstract

An introducer assembly for use in delivering an implantable device to a target site within the vasculature of a patient includes an outer sheath and an inner catheter sized for passage through the lumen of the sheath. The outer sheath has a shaft portion and a tapered distal tip portion, and the inner catheter is sized for carrying the implantable device thereon. The tapered distal tip portion includes a frangible portion capable of splitting when the portion of the inner catheter having the implantable device thereon passes through the sheath distal tip portion for deployment of the implantable device at the target site.

Claims

1. A sheath for delivering an implantable device to a target area in the vasculature of a patient, comprising:

an elongated shaft portion having a proximal end and a distal end; and

a tip portion, said tip portion having a larger diameter proximal end and tapering to a smaller diameter distal end, said tip portion proximal end engaged with said shaft portion distal end, said tip portion including at least one weakened portion extending in the proximal direction from said tip portion distal end, said tip portion capable of splitting at said weakened portion upon delivery of said implantable device therethrough.

2. The sheath of claim 1, wherein said tip portion includes a plurality of longitudinally weakened portions extending in the proximal direction from said tip portion distal end, wherein said tip portion is capable of splitting at said longitudinally weakened portions upon delivery of said implantable device.

3. The sheath of claim 2, wherein said weakened portions comprise radial slits extending inwardly from an outer surface of said tip portion.

4. The sheath of claim 3, wherein said radial slits terminate short of an inner surface of said tip portion.

5. The sheath of claim 2, wherein said longitudinally weakened portions extend in the proximal direction substantially to an area of engagement of said shaft portion distal end and said tip portion proximal end.

6. The sheath of claim 2, wherein said longitudinally weakened portions are substantially spaced an equal distance along a surface of said tip portion.

7. The sheath of claim 6, comprising four weakened portions spaced about 90 degrees apart along a surface of said tip portion.

8. An introducer assembly for delivering an implantable device to a target site in the vasculature of a patient, comprising:

an outer sheath, said sheath comprising an elongated shaft portion and a tip portion, said elongated shaft portion having a proximal end and a distal end, said tip portion having a larger diameter proximal end and tapering to a smaller diameter distal end, said tip portion proximal end engaged with said shaft portion distal end, said shaft portion and said tip portion defining a lumen extending axially through said sheath; and

an inner catheter disposed in said sheath lumen and capable of axial movement substantially through said lumen, said inner catheter sized for carrying said implantable device thereon, said inner catheter with said implantable device carried thereon structured and arranged such that upon distal movement of at least a portion of said inner catheter relative to said sheath tip portion said tip portion distal end splits for passage of said inner catheter portion therethrough.

9. The introducer assembly of claim 8, wherein said tip portion includes at least one weakened portion extending in the proximal direction from said tip portion distal end, said tip portion capable of splitting at said weakened portion upon passage of said inner catheter portion therethrough.

10. The introducer assembly of claim 9, wherein said inner catheter includes a generally conical portion distal of a portion of said inner catheter adapted for carrying said implantable device, said generally conical portion having a large diameter portion exceeding a diameter of said distal end of said tapered tip portion.

11. The introducer assembly of claim 9, wherein said inner catheter includes a generally conical portion distal of a portion of said inner catheter adapted for carrying said implantable device, said generally conical portion having a large diameter portion exceeding a diameter of said distal end of said tapered tip portion, said inner catheter further comprising a distal end portion extending through said distal end of said tip portion.

12. The introducer assembly of claim 8, further comprising an inflatable balloon positioned at a distal portion of said inner catheter, and an inflation lumen positioned for carrying an inflation fluid to an interior portion of said balloon for inflation thereof, said inflatable balloon oriented on said inner catheter for carrying said implantable device.

13. The introducer assembly of claim 12, wherein said inner catheter includes a generally conical portion distal of said inflatable balloon, said generally conical portion having a large diameter portion exceeding a diameter of said distal end of said tip portion.

14. The introducer assembly of claim 8, wherein said inner catheter includes a pusher portion proximal of a portion of said inner catheter carrying said implantable device.

15. The introducer assembly of claim 8, wherein said inner catheter comprises at least one cutter distal of a portion of said catheter assembly adapted for carrying said implantable device, said at least one cutter structured and arranged such that upon said relative distal movement said cutter forms a weakened portion in said tip portion distal end.

16. The introducer assembly of claim 15, wherein said inner catheter comprises a generally conical portion distal of said portion adapted for carrying said implantable device, and wherein said at least one cutter extends longitudinally along a surface of said generally conical portion.

17. A method for delivering an implantable device to a target site within the vasculature of a patient, comprising:

providing an introducer assembly for insertion into a vessel of a patient, said introducer assembly comprising a sheath and an inner catheter, said sheath comprising an elongated shaft portion and a tip portion, said elongated shaft portion having a proximal end and a distal end, said tip portion having a larger diameter proximal end and tapering to a smaller diameter distal end, said tip portion proximal end engaged with said shaft portion distal end, said tip portion including at least one longitudinally weakened portion extending in the proximal direction from said tip portion distal end, said shaft portion and said tip portion defining a lumen extending axially through said sheath;

said inner catheter disposed in said sheath lumen and capable of axial movement therein, said inner catheter sized for carrying said implantable device thereon, a portion of said inner catheter having a profile when carrying said implantable device such that upon movement of at least said profiled portion of said inner catheter through said tip portion distal end for delivery of said device to said target site, said tip portion splits along said at least one weakened portion;

inserting a distal end portion of said introducer assembly into said vessel;

advancing said introducer assembly distal end portion to said target site;

moving said inner catheter in a distal direction relative to said tip portion distal end such that said inner catheter profiled portion splits said tip distal end along said at least one weakened portion to enable passage therethrough of said profiled portion carrying said implantable device; and

deploying said implantable device from said inner catheter into said vessel.

18. The method of claim 17, wherein said implantable device comprises an expandable stent, and said deploying step comprises delivery of said stent to said target site, and expanding said stent from a compressed condition to an expanded condition.

19. The method of claim 18, wherein said inner catheter comprises an inflatable balloon, and said stent is expanded by inflating said balloon.

20. The method of claim 17, wherein said inner catheter comprises a generally conical portion distal of a portion of said inner catheter adapted for carrying said implantable device, said generally conical portion having a large diameter portion exceeding a diameter of said distal end of said tapered tip portion.