Stent systems and methods for spine treatment

• US 20060100706A1
• Filed: 05/16/2005
• Published: 05/11/2006
• Est. Priority Date: 11/10/2004
• Status: Abandoned Application

• Current Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Original Assignee: Dfine Incorporated (Merit Medical Systems, Inc.)
• Inventors: Shadduck, John H., Truckai, Csaba
• Application Number:
  US11/130,843
• Publication Number:
  US 20060100706A1
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61B 17/1617 with mobile or detachable parts
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/7098 wherein the implant is permeable or has openings, e.g. fenestrated screw hollow surgical screws A61B17/864
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity

Abstract

Stent systems and methods for expanding and deploying stents in hard tissue such as bone, more particularly within a vertebral body. One exemplary method includes using a stent body that is coupled to a high speed rotational motor with the stent expandable and detachable from an introducer working end. In one embodiment, the stent is a deformable metal body with zig-zag type struts in an expanded configuration that carries diamond cutting particles bonded to the strut surfaces. The “spin” stent is rotated at high rpm'"'"'s to remove cancellous bone from the deployment site together with irrigation and aspiration at the end of the probe that carries the stent. The stent may be expanded asymmetrically, such as with first and second balloons or by using an interior restraint, to apply vertical distraction forces to move apart the cortical endplates and support the vertebra in the distracted condition. The cancellous bone about the expanded stent as well as the interior of the stent can be filled with a bone cement, allograft or other bone graft material. In one method of use, the spin stent is designed and adapted for (i) treating a vertebral compression fracture (VCF) or for (ii) reinforcing an osteoporotic vertebral body.

Claims

1. A method for treating a vertebral body, comprising:

inserting a stent into the vertebral body in substantial contact with cancellous bone;

rotating the stent to cut cancellous bone from the vertebral body; and

expanding the stent to support the vertebral body.

2. The method of claim 1, wherein the stent is rotated and expanded simultaneously.

3. The method of claim 1, wherein the stent is expanded to a symmetric configuration.

4. The method of claim 1, wherein the stent is expanded to an asymmetric configuration.

5. The method of claim 1, wherein the stent is first expanded to a symmetric configuration, and is then expanded to an asymmetric configuration.

6. The method of claim 1, wherein introducing the stent includes introducing the stent through a pedicle to the vertebral body.

7. The method of claim 1, wherein the stent is introduced into the vertebral body minimally invasively.

8. The method of claim 1, further comprising:

irrigating the vertebral body; and

suctioning cut bone debris from the vertebral body.

9. The method of claim 1, wherein expanding the stent includes expanding the stent into substantial contact with cortical bone endplates of the vertebral body.

10. The method of claim 1, further comprising inserting the stent with an introducer, and detaching the stent from the introducer following expansion.

11. The method of claim 1, wherein the stent is rotated at a speed of between about 100 rpm to about 50,000 rpm.

12. The method of claim 1, further comprising introducing a fill material through the stent and into the vertebral body.

13. The method of claim 1, wherein expanding the stent includes expanding at least one balloon disposed within the stent.

14. The method of claim 1, comprising:

inserting a plurality of stents into the vertebral body in substantial contact with cancellous bone;

rotating the stents to cut cancellous bone from a treatment site; and

expanding the stents to support the vertebral body.

15. A method for treating a vertebral body, comprising:

inserting a stent into the vertebral body, the stent having a collapsed configuration and an expanded configuration;

cutting cancellous bone with the stent;

expanding the stent within the vertebral body; and

releasing the stent such that the stent remains in place to support the vertebral body.

16. The method of claim 15, comprising rotating the stent to cut the cancellous bone.

17. The method of claim 15, wherein the stent is expanded simultaneously with cutting the cancellous bone.

18. The method of claim 15, wherein the stent is made of metal.

19. The method of claim 15, further comprising injecting bone cement into the stent after expansion.

20. The method of claim 19, further comprising directing bone cement through openings in the stent and outside the stent to support the vertebral body.

21. The method of claim 15, wherein the stent is inserted on the end of an introducer.

22. The method of claim 21, wherein the stent is carried on an inner shaft extending through an elongated shaft of the introducer.

23. The method of claim 22, wherein the stent is expanded by drawing proximal and distal ends of the stent closer together.

24. The method of claim 22, wherein the inner shaft is rotatable to cut the cancellous bone with the stent.

25. The method of claim 21, wherein releasing the stent comprising releasing the introducer from the stent.

26. The method of claim 15, further comprising delivering a balloon into the expanded stent after injecting bone cement into the stent, and expanding the balloon against hardened bone cement.

27. The method of claim 15, wherein the stent is expanded with at least one balloon.

28. A method for treating a vertebral body, comprising:

inserting a stent into the vertebral body;

expanding the stent asymmetrically such that the stent applies a greater expansion force along an axis extending generally between two cortical end plates of the vertebral body than within a plane generally parallel to the two cortical end plates; and

releasing the stent such that the stent remains in place to support the vertebral body.

29. The method of claim 28, further comprising using the stent to cut cancellous bone from within the vertebral body.

30. The method of claim 29, further comprising using at least one of irrigation and aspiration to remove cut bone material.

31. The method of claim 28, further comprising expanding the stent symmetrically before expanding the stent asymmetrically.

32. The method of claim 28, wherein the stent is expanded with at least one balloon.

33. The method of claim 28, wherein the stent is expanded with two balloons.

34. The method of claim 32, wherein a restraint is provided around at least a portion of the balloon to cause the stent to expand asymmetrically.

35. The method of claim 28, wherein the stent is rotated to align said stent before asymmetrical expansion.

36. A method for treating a bone, comprising:

introducing an expandable stent having surface abrasives into an interior of the bone;

spinning the stent to cut the bone; and

expanding the stent;

wherein the stent after spinning provides bone support to prevent subsidence.

37. The method of claim 36, wherein spinning and expanding the stent occur simultaneously.

38. The method of claim 36, further comprising irrigating and aspirating cut bone debris.

39. The method of claim 36, wherein expanding the stent is accomplished by forces applied by at least one of a mechanical stent-expansion mechanism, a balloon stent-expansion mechanism, the release of energy stored in a shape memory stent body, and centrifugal force.

40. The method of claim 36, further comprising filling the interior of the bone with at least one of a bone cement, bone allograft or bone autograft.

41. The method of claim 36, comprising introducing the expandable stent into a vertebral body.

42-117. -117. (canceled)