CLOT RETRIEVAL DEVICES

• US 20140277079A1
• Filed: 03/14/2013
• Published: 09/18/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Neuravi Limited (Johnson & Johnson)
• Original Assignee: Neuravi Limited (Johnson & Johnson)
• Inventors: Vale, David, Brady, Eamon, Gilvarry, Michael, Ravazi, Mahmood
• Granted Patent: US 9,433,429 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• 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 2017/22034 for gripping the obstruction or the tissue part from inside
• CPC Class Codes: A61B 2017/22061 for spreading elements apart
• CPC Class Codes: A61B 2017/22094 for crossing total occlusions, i.e. piercing
• CPC Class Codes: A61B 2017/2215 having an open distal end

Abstract

A self-expandable mechanical clot retrieval device is designed variously to dislodge, engage and retract blood clot from extremely small and tortuous vasculature. The retrieval device comprises an elongate member and a plurality of ring elements. The ring elements may comprise a plurality of struts and crowns interconnected by a tether formed at a distal end of the elongate member or may be a separate component attached thereto. At least one tether may connect each ring element to the elongate member to restrain the ring element in a collapsed configuration during delivery of the retrieval device through an intravascular microcatheter. The tether connecting the ring element to the elongate member disengages when the retrieval device is positioned at the occluded site and the microcatheter is retracted to allow the self-expandable ring elements to reach an expanded configuration.

Claims

1. A clot retrieval device comprising:

—

an elongate member and a plurality of clot engaging elements at a distal end of the elongate member, the clot engaging elements being self expandable and having a retracted delivery configuration and an expanded deployed configuration; and

a biasing element for biasing the clot engaging elements into a retracted delivery configuration against the elongate member;

the biasing element being releasable to allow the clot engaging elements to expand into the deployed configuration.

2. A device as claimed in claim 1 wherein the elongate member extends exterior of the patient in use.

3. A device as claimed in claim 1 wherein the diameter of the clot engaging elements in the deployed configuration is greater than the diameter of the clot engaging elements in the retracted configuration.

4. A device as claimed in claim 1 wherein the biasing element is integral with the clot engagement elements.

5. A device as claimed in claim 1 wherein the biasing element is integral with the elongate member.

6. A device as claimed in claim 1 wherein the biasing element is connected to either the clot engagement elements, the elongate member or to both.

7. A device as claimed in claim 1 wherein the biasing element comprises a snap element, a restraining element, a tether, an interlocking element, an overlapping element of the clot engagement element, an abutment element, a connector element, a housing, a pair of interacting elements, or a limiting element configured to limit at least one degree of expansion movement.

8. A device as claimed in claim 7 wherein the clot engagement elements comprise a plurality of struts and said biasing element is configured to limit relative movement between at least a pair of said struts.

9. A device as claimed in claim 7 wherein the biasing element is configured to limit relative movement between the clot engagement elements and the elongate member.

10. A device as claimed in claim 1 wherein the elongate member is configured to activate the biasing element.

11. A device as claimed in claim 1 wherein the device further comprises an activation element which is configured to affect the release of the biasing element.

12. A device as claimed in claim 11 wherein activation element comprises an elongate tube, an elongate member, or a tether.

13. A clot retrieval device comprising:

—

an elongate member, a first clot engaging element and a second clot engaging element, the first clot engaging element distal of the second clot engaging element,

the clot engaging elements being self expandable and having a sheathed delivery configuration, a deployed configuration and a fully expanded configuration; and

at least one release element for biasing the clot engaging elements in the deployed configuration;

activation of the at least one release element allowing the clot engaging elements to expand into the fully expanded configuration.

14. A device as claimed in claim 13 wherein the sheathed configuration comprises sheathing within the lumen of a micro catheter.

15. A device as claimed in claim 14 wherein unsheathing the clot engaging elements allows the clot engaging elements to assume the deployed configuration.

16. A device as claimed in claim 15 wherein the diameter of the clot engaging elements in the deployed configuration is greater than the diameter of the clot engaging elements in the sheathed configuration.

17. A device as claimed in claim 16 wherein the first clot engagement element assumes the expanded configuration while the second clot engaging element is in the deployed configuration.

18. A device as claimed in claim 13 wherein the release element is configured to bias the clot engaging elements in a deployed configuration.

19. A device as claimed in claim 13 wherein the release element is integral with the clot engagement elements.

20. A device as claimed in claim 13 wherein the release element is integral with elongate member.

21. A device as claimed in claim 13 wherein the release element is connected to either the clot engagement elements, the elongate member or to both.

22. A device as claimed in claim 13 wherein the release element comprises a snap element, a restraining element, a tether, an interlocking element, an overlapping element of the clot engagement element, an abutment element, a connector element, a housing, a pair of interacting elements, or a limiting element configured to limit at least one degree of expansion movement.

23. A device as claimed in claim 13 wherein the elongate member is configured to activate the release element.

24. A device as claimed in claim 13 wherein the device further comprises an activation element which is configured to affect the release of the release element.

25. A device as claimed in claim 24 wherein the activation element comprises an elongate tube, an elongate member, or a tether.

26. A method for retrieval of a clot comprising the steps of:

—

providing a clot retrieval device the clot retrieval device comprising an elongate member and a plurality of clot engaging elements at a distal end of the elongate member, the clot engaging elements having a retracted configuration, a partially expanded configuration and an expanded configuration;

providing a biasing element for limiting the expansion of the clot engaging elements;

advancing a microcatheter across a clot;

advancing the elongate member with the clot engaging elements in a retracted configuration through the microcatheter so that at least some of the clot engaging elements are distal of the clot;

retracting the microcatheter so as to unsheath at least one clot engaging element;

activating the biasing element so as to trigger the expansion of at least one of said clot engagement elements to the expanded configuration; and

retracting the clot retrieval device and the clot into a proximal retrieval element.

27. A method as claimed in claim 26 wherein the step of retracting the microcatheter further comprises the step of expanding the at least one clot engagement element to the partially expanded configuration.

28. A method as claimed in claim 26 wherein the step of activating the biasing element comprises the step of applying an activation force to the biasing element

29. A method as claimed in claim 26 wherein the step of activating the biasing element comprises the step of applying a compressive, tensile, twisting or radial force to the biasing element.

30. A method as claimed in claim 26 wherein the method comprises the step of providing a plurality of clot engagement elements configured such that in the partially expanded configuration there exists a lumen through the centre of said clot engagement elements, said lumen being larger than the diameter of the microcatheter and smaller than the diameter of the vessel.

31. A method as claimed in claim 26 wherein the method comprises the step of expanding a plurality of said clot engagement segments so as to create a lumen for blood flow through the clot.

32. A method as claimed in claim 26 wherein the method comprises the step of holding the clot retrieval device steadfast in the vessel for a time period of at least one minute.