Releasable Delivery System

• US 20170079819A1
• Filed: 09/19/2016
• Published: 03/23/2017
• Est. Priority Date: 09/18/2015
• Status: Active Grant

• Current Assignee: Microvention Incorporated (Terumo Corporation)
• Original Assignee: Microvention Incorporated (Terumo Corporation)
• Inventors: Pung, Ponaka, Tieu, Tai D., Soltanian, Ross, Nguyen, Helen, Nguyen, Oanh, Ngo, Britney
• Granted Patent: US 10,182,931 B2
• Time in Patent Office: Days
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/9665 with additional retaining means
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers

Abstract

Implant engagement mechanisms are disclosed for maintaining engagement with a stent until it has been fully deployed and expanded from a catheter or sheath. The apparatus, method and system involving these engagement mechanisms allow a physician to withdraw or retract a sheath prior to full deployment, thereby allowing for redeployment of the stent at a more desirable position.

Claims

1. A delivery pusher to deliver a stent within a delivery sheath for an endovascular procedure comprising:

an elongated member;

a stent engagement mechanism located on a distal portion of the elongated member;

wherein the stent engagement mechanism engages with the proximal portion of the stent when the stent is in a compressed configuration within the delivery sheath and disengages with the proximal portion of the stent as the stent exits the delivery sheath and expands to a full-sized configuration.

2. The delivery pusher of claim 1, wherein the stent engagement mechanism is one or more protruding elements radially extending from distal portion of the elongated member.

3. The delivery pusher of claim 2, wherein the protruding elements are posts.

4. The delivery pusher of claim 3, further comprising a radially enlarged member fixed to the elongated member at a location proximal of the one or more protruding elements.

5. The delivery pusher of claim 3, wherein the one or more posts are perpendicularly angled, distally angled, or proximally angled relative to the elongated member.

6. The delivery pusher of claim 3, wherein the posts are distributed at radially equidistant locations from each other.

7. The delivery pusher of claim 3, wherein the posts are distributed in axially offset locations relative to each other.

8. The delivery pusher of claim 2, wherein the protruding elements are a plurality of axially elongated blocks.

9. The delivery pusher of claim 8, wherein the plurality of axially elongated blocks are rectangular.

10. The delivery pusher of claim 2, wherein the protruding elements are a plurality of marker bands fixed to one or more support wires.

11. The delivery pusher of claim 10, wherein the support wires each have at least one end connected to the elongated member and support the marker bands in a position away from a center diameter of the elongated member.

12. The delivery pusher of claim 10, wherein the marker bands can move radially relative to the elongated member.

13. The delivery pusher of claim 10, wherein the support wires have two ends attached to the elongated member so as to create an arc shape.

14. The delivery pusher of claim 1, wherein the stent engagement mechanism comprises one or more channels sized to engage a wire of the stent.

15. The delivery pusher of claim 14, wherein the elongated member further comprises a tubular portion near a distal end of the elongated member, and wherein the one or more channels are located through the tubular portion.

16. The delivery pusher of claim 14, wherein the channels comprise a distal portion having a first width and a proximal portion having a second width that is larger than the first width.

17. The delivery pusher of claim 16, wherein the first width is smaller than a wire diameter of the stent and wherein the second width is larger than the wire diameter of the stent.

18. The delivery pusher of claim 15, wherein a distal end of the tubular portion increases in diameter when unconstrained by the delivery sheath.

19. The delivery pusher of claim 18, wherein the channels comprise a distal portion having a first width and a proximal portion having a second width that is larger than the first width;

wherein the first width is smaller than a wire diameter of the stent and wherein the second width is larger than the wire diameter of the stent; and

wherein the distal portion increases in width when the tubular portion increases in diameter.

20. The delivery pusher of claim 14, wherein the channels are sized to engage rounded portions on the stent.

21. The delivery pusher of claim 1, wherein the stent engagement mechanism is a cable having a first end permanently fixed to the elongated member and a second end releasably engaged with a notch in the stent engagement mechanism;

whereby the second end moves out of the notch when the cable is unconstrained by the sheath.

22. A stent delivery system comprising:

a stent with a proximal loop;

an arm extending from the proximal loop, wherein the arm includes an enlarged portion;

a pusher used to deliver the stent;

a distal portion of the pusher comprising a recess sized to accommodate the enlarged portion of the arm;

wherein the enlarged portion is located within the recess when the enlarged portion resides within a catheter.

23. The stent delivery system of claim 22, wherein the arm extends proximally within the delivery system.

24. The stent delivery system of claim 22, where the recess comprises a channel having a proximal portion having a first width and a distal portion having a second width that is larger than the first width.

25. The stent delivery system of claim 23, further comprising a plurality of recesses, wherein the distal portion of the channel of some of the plurality of the recesses are axially offset from each other.

26. The stent delivery system of claim 23, wherein said stent has an angled proximal end terminating in only with the proximal loop.