EMBOLIC OBSTRUCTION RETRIEVAL DEVICES AND METHODS

• US 20110009875A1
• Filed: 07/08/2009
• Published: 01/13/2011
• Est. Priority Date: 07/08/2009
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Concentric Medical, Inc. (Stryker Corporation)
• Inventors: H. Sanders, Elliot, L. Bonsignore, Craig, L. Pedersen, Kirk, Miller, John H., Vu, Emily, Grandfield, Ryan M., Wilson, Scott D.
• Granted Patent: US 8,795,317 B2
• Time in Patent Office: Days
• US Class Current: 606/127
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61B 2017/2215 having an open distal end
• CPC Class Codes: A61B 2017/2217 single wire changing shape to a gripping configuration

Abstract

An embolic obstruction retrieval device including a self-expandable member having a proximal end portion, a main body portion and a distal end portion. Each of the self-expandable portions consists of a plurality of cell structures formed by intersecting strut members. At least one proximal cell structure in the proximal end portion has one or more struts that have a width and/or thickness greater than the width and/or thickness of the majority of strut members in the main body and distal end portions of the expandable member. Attached to at least one of the proximal-most cell structures in the proximal end portion is a proximally extending flexible wire having sufficient length and flexibility to navigate the tortuous vasculature and access the embolic obstruction. In one implementation, the embolic obstruction retrieval device is delivered to the embolic obstruction through the lumen of a delivery catheter.

Claims

1. An embolic obstruction retrieval device comprising:

an elongate self-expandable member movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within an embolic obstruction of a patient, the expandable member comprising a plurality of generally longitudinal undulating elements with adjacent undulating elements being interconnected in a manner to form a plurality of diagonally disposed cell structures, the expandable member having a proximal end portion, a cylindrical main body portion and a distal end portion, the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member, the cell structures in the proximal and distal end portions extending less than circumferentially around the longitudinal axis of the expandable member, the outer-most cell structures in the proximal end portion having proximal-most linear wall segments that, in a two-dimensional view, form first and second substantially linear rail segments that each extend from a position at or near the proximal-most end of the expandable member to a position at or near the cylindrical main body portion; and

a first proximally extending elongate flexible wire connected to the proximal-most end of the expandable member.

2. The embolic obstruction retrieval device of claim 1, further comprising an elongate wire segment that extends distally to the distal-most end of the expandable member.

3. The embolic obstruction retrieval device of claim 2, wherein the elongate wire segment comprises an atraumatic tip.

4. The embolic obstruction retrieval device of claim 1, wherein the proximal-most cell structure is substantially diamond shaped in the two-dimensional view.

5. The embolic obstruction retrieval device of claim 1, wherein the proximal-most cell structure is substantially diamond shaped in the two-dimensional view and has first and second inner rails, the first and second inner rails forming an angle of between about 30.0 to about 45.0 degrees with the first and second linear rail segments, respectively.

6. The embolic obstruction retrieval device of claim 1, wherein the proximal-most cell structure is substantially diamond shaped in the two-dimensional view and has first and second inner rails, the first and second inner rails forming an angle of between about 30.0 to about 45.0 degrees with the first and second linear rail segments, respectively, and being connected to the linear rail segments via curved connectors.

7. The embolic obstruction retrieval device of claim 1, wherein the first and second continuous rail segments are of the same length.

8. The embolic obstruction retrieval device of claim 1, wherein the proximal-most linear wall segments have a width and/or thickness greater than the undulating elements in the expandable member.

9. The embolic obstruction retrieval device of claim 1, wherein in the radially expanded position the cylindrical body portion comprises a first region and a second region, the second region having a diameter greater than the first region.

10. The embolic obstruction retrieval device of claim 9, wherein the diameter of the second region is between about 25.0 to about 35.0 percent greater than the diameter of the first region.

11. The embolic obstruction retrieval device of claim 9, wherein the second region is located distal to the first region.

12. The embolic obstruction retrieval device of claim 9, wherein the second region is located at a distal end of the cylindrical body portion.

13. The embolic obstruction retrieval device of claim 1, wherein at least a portion of the expandable member is coated with a radiopaque material.

14. The embolic obstruction retrieval device of claim 1, further comprising radiopaque markers positioned at or near the proximal-most and distal-most ends of the expandable member.

15. The embolic obstruction retrieval device of claim 1, wherein in the radially expanded position, the taper angle between the elongate wire and the two substantially continuous linear rail segments is between about 30.0 and about 40.0 degrees as measured in the two-dimensional view.

16. The embolic obstruction retrieval device of claim 2, wherein the elongate wire segment includes a taper portion and is bound by a coil structure.

17. The embolic obstruction retrieval device of claim 16, wherein the coil structure comprises a radiopaque material.

18. The embolic obstruction retrieval device of claim 1, wherein the length of the cylindrical main body portion is between about 2.5 and about 3.5 times greater than the length of either the first or second end portions.

19. The embolic obstruction retrieval device of claim 1, wherein the cell structures in the proximal end portion and distal end portion are generally larger than the cell structures in the cylindrical main body portion.

20. The embolic obstruction retrieval device of claim 1, further comprising a second proximally extending elongate wire connected to one of the first or second linear rail segments.

21. The embolic obstruction retrieval device of claim 1, further comprising a second proximally extending elongate wire connected to the first linear rail segment and a third proximally extending elongate wire connected to the second linear rail segment.

22. The embolic obstruction retrieval device of claim 21, wherein the second proximally extending elongate wire is connected at or near the distal end of the first linear rail segment and the third proximally extending elongate wire is connected at or near the distal end of the second linear rail segment.

23. An embolic obstruction retrieval device comprising:

an elongate self-expandable member movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within an embolic obstruction of a patient, the expandable member comprising a plurality of generally longitudinal undulating elements with adjacent undulating elements being interconnected in a manner to form a plurality of cell structures that are arranged to induce twisting of the expandable member as the expandable member transitions from the unexpanded position to the expanded position, the expandable member having a proximal end portion, a cylindrical main body portion and a distal end portion, the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member, the cell structures in the proximal and distal end portions extending less than circumferentially around the longitudinal axis of the expandable member, the outer-most cell structures in the proximal end portion having proximal-most linear wall segments that form first and second substantially linear rail segments that each extend from a position at or near the proximal-most end of the expandable member to a position at or near the cylindrical main body portion; and

a first proximally extending elongate flexible wire connected to the proximal-most end of the expandable member.

24. An embolic obstruction retrieval device comprising:

an elongate self-expandable member movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within an embolic obstruction of a patient, the expandable member comprising a plurality of generally longitudinal undulating elements with adjacent undulating elements being interconnected to form a plurality of diagonally disposed cell structures, the expandable member having a cylindrical portion and a distal end portion, the cell structures in the cylindrical portion extending circumferentially around a longitudinal axis of the expandable member, the cell structures in the distal end portion extending less than circumferentially around the longitudinal axis of the expandable member, the proximal-most cell structures in the main body portion having proximal-most end points, one or more of the proximal-most end points of the expandable member having a proximally extending elongate flexible wire connected thereto.

25. The embolic obstruction retrieval device of claim 24, further comprising an elongate wire segment that extends distally from the distal-most end of the expandable member.

26. The embolic obstruction retrieval device of claim 25, wherein the elongate wire segment comprises an atraumatic tip.

27. The embolic obstruction retrieval device of claim 24, wherein the proximal-most cell structures are polygons as seen in a two-dimensional view.

28. The embolic obstruction retrieval device of claim 24, wherein the proximal-most cell structures are polygons as seen in a two-dimensional view, each comprising first and second substantially linear outer struts and first and second substantially linear inner struts, the first and second substantially linear inner struts forming an angle of between about 30.0 to about 45.0 degrees, as seen in the two-dimensional view, with the first and second substantially linear outer struts, respectively, as seen in the two-dimensional view.

29. The embolic obstruction retrieval device of claim 24, wherein the proximal-most cell structures are polygons as seen in a two-dimensional view, each comprising first and second substantially linear outer struts and first and second substantially linear inner struts, the first and second substantially linear inner struts forming an angle of between about 30.0 to about 45.0 degrees, as seen in the two-dimensional view, with the first and second substantially linear outer struts, respectively, and being connected to the substantially linear outer struts by curved connectors.

30. The embolic obstruction retrieval device of claim 27, wherein one or more of the proximal-most cell structures comprise one or more struts having a width and/or thickness greater than that of the curvilinear struts in the main body portion of the expandable member.

31. The embolic obstruction retrieval device of claim 24, wherein in the radially expanded position the cylindrical portion comprises a first region and a second region, the second region having a diameter greater than the first region.

32. The embolic obstruction retrieval device of claim 31, wherein the diameter of the second region is between about 25.0 to about 35.0 percent greater than the diameter of the first region.

33. The embolic obstruction retrieval device of claim 31, wherein the second region is located distal to the first region.

34. The embolic obstruction retrieval device of claim 31, wherein the second region is located at a distal-most end of the cylindrical portion.

35. The embolic obstruction retrieval device of claim 25, wherein the elongate wire segment has a taper portion and is bound by a coil structure.

36. The embolic obstruction retrieval device of claim 35, wherein the coil structure comprises a radiopaque material.

37. The embolic obstruction retrieval device of claim 24, wherein the cell structures in the distal end portion are generally larger than the cell structures in the cylindrical portion.

38. A kit comprising:

an elongate flexible wire having a proximal end and a distal end with an elongate self-expandable member attached to the distal end, the self-expandable member movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within an embolic obstruction of a patient, the expandable member comprising a plurality of generally longitudinal undulating elements with adjacent undulating elements being interconnected in a manner to form a plurality of diagonally disposed cell structures, the expandable member having a proximal end portion, a cylindrical main body portion and a distal end portion, the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member, the cell structures in the proximal and distal end portions extending less than circumferentially around the longitudinal axis of the expandable member, the outer-most cell structures in the proximal end portion having proximal-most linear wall segments that, in a two-dimensional view, form first and second substantially linear rail segments that each extend from a position at or near the proximal-most end of the expandable member to a position at or near the cylindrical main body portion, the elongate wire with the expandable member having a first length; and

a delivery catheter having a second length and sufficient flexibility to navigate the tortuous intracranial vasculature of a patient, the delivery catheter having a proximal end, a distal end and an inner lumen, the inner lumen having a diameter sufficient to receive the expandable member in its unexpanded position and for advancing the unexpanded member from the proximal end to the distal end of the catheter, the second length being less than the first length to allow distal advancement of the expandable member beyond the distal end of the catheter to permit the expandable member to deploy toward its expanded position,

the distal end of the catheter and the expandable member configured to permit proximal retraction of the expandable member into the lumen of the catheter when the expandable member is partially or fully deployed outside the distal end of the catheter.

39. A method for removing an embolic obstruction from a vessel of a patient comprising:

advancing a delivery catheter having an inner lumen with a proximal end and a distal end to the site of an embolic obstruction in the intracranial vasculature of a patient so that the distal end of the inner lumen is positioned distal to the embolic obstruction, the inner lumen having a first length,

introducing an embolic obstruction retrieval device comprising an elongate flexible wire having a proximal end and a distal end with an elongate self-expandable member attached to the distal end into the proximal end of the inner lumen of the delivery catheter and advancing the self-expandable member to the distal end of the lumen, the self-expandable member movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within an embolic obstruction of a patient, the expandable member comprising a plurality of generally longitudinal undulating elements with adjacent undulating elements being interconnected in a manner to form a plurality of diagonally disposed cell structures, the expandable member having a proximal end portion, a cylindrical main body portion and a distal end portion, the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member, the cell structures in the proximal and distal end portions extending less than circumferentially around the longitudinal axis of the expandable member, the outer-most cell structures in the proximal end portion having proximal-most linear wall segments that, in a two-dimensional view, form first and second substantially linear rail segments that each extend from a position at or near the proximal-most end of the expandable member to a position at or near the cylindrical main body portion, the elongate wire and expandable member in combination having a second length longer than the first length,

proximally retracting the delivery catheter sufficient to deploy the self-expandable device so that the one or more of the cell structures entrap at least a portion of the embolic obstruction; and

proximally retracting the delivery catheter and self-expanding member to outside the patient.

40. A method according to claim 39, further comprising proximally retracting the self-expandable member partially into the inner lumen of the delivery catheter prior to proximally retracting the delivery catheter and self-expandable device to outside the patient.

41. A method for removing an embolic obstruction from a vessel of a patient comprising:

advancing a delivery catheter having an inner lumen with a proximal end and a distal end to the site of an embolic obstruction in the intracranial vasculature of a patient so that the distal end of the inner lumen is positioned distal to the embolic obstruction and in a manner to create a perfusion channel through the embolic obstruction that causes blood flow to pass through the embolic obstruction for a period of time, the inner lumen having a first length,

introducing an embolic obstruction retrieval device comprising an elongate flexible wire having a proximal end and a distal end with an elongate self-expandable member connected to the distal end into the proximal end of the inner lumen of the delivery catheter and advancing the self-expandable member to the distal end of the lumen, the elongate flexible wire and expandable member in combination having a second length longer than the first length,

after the period of time has elapsed, deploying the self-expandable member inside the obstruction so that the expandable member captures at least part of the embolic obstruction, the period of time being sufficient to cause the blood flow to act on the embolic obstruction to make it more easily capturable by the self-expanding member; and

proximally retracting the delivery catheter and self-expanding member to outside the patient.