Embolectomy catheters and methods for treating stroke and other small vessel thromboembolic disorders

• US 20040133232A1
• Filed: 12/09/2003
• Published: 07/08/2004
• Est. Priority Date: 05/01/1998
• Status: Active Grant

• Current Assignee: Microvention Incorporated (Terumo Corporation)
• Original Assignee: Microvention Incorporated (Terumo Corporation)
• Inventors: Sternweiler, Thomas R., Rosenbluth, Robert F., Cox, Brian J., Monetti, Richard R., Green, George R. Jr., Chow, Sean L.
• Granted Patent: US 7,691,121 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61B 17/135 inflatable for measuring blood pressure A61B5/022; inflatable pressure pads A61F5/34
• CPC Class Codes: A61B 17/22032 having inflatable gripping elements balloon catheters A61M25/10
• 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 2017/22044 with a pointed tip
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2017/22084 stone- or thrombus-dissolving
• CPC Class Codes: A61B 2017/22094 for crossing total occlusions, i.e. piercing
• CPC Class Codes: A61B 2017/2212 having a closed distal end, e.g. a loop
• CPC Class Codes: A61B 2017/320716 comprising means for preventing embolism by dislodged material
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61M 2025/0042 Microcatheters, cannula or the like having outside diameters around 1 mm or less
• CPC Class Codes: A61M 2025/0183 Rapid exchange or monorail catheters

Abstract

Embolectomy catheters, rapid exchange microcatheters, systems and methods for removing clots or other obstructive matter (e.g., thrombus, thromboemboli, embolic fragments of atherosclerotic plaque, foreign objects, etc.) from blood vessels. This invention is particularly useable for percutaneous removal of thromboemboli or other obstructive matter from small blood vessels of the brain, during an evolving stroke or period of cerebral ischemia. In some embodiments, the embolectomy catheters of this invention are advanceable with or over a guidewire which has been pre-inserted through or around the clot. Also, in some embodiments, the embolectomy catheters include clot removal devices which are deployable from the catheter after the catheter has been advanced at least partially through the clot. The clot removal device may include a deployable wire nest that is designed to prevent a blood clot from passing therethrough. The delivery catheter may include telescoping inner and outer tubes, with the clot removal device being radially constrained by the outer tube. Retraction of the outer tube removes the constraint on the clot removal device and permits it to expand to its deployed configuration. An infusion guidewire is particularly useful in conjunction with the embolectomy catheter, and permits infusion of medicaments or visualization fluids distal to the clot.

Claims

1. An embolectomy catheter for removing a blood clot or other such obstructive matter from a blood vessel, the catheter comprising:

an elongate flexible catheter body having a proximal end, a distal end, an inner tube, and a guidewire lumen a part of which extends longitudinally through the inner tube, the guidewire lumen being sized to receive a guidewire therein and being open on its distal end to permit the guidewire so received to project distally from the distal end of the catheter body; and

a clot removal device on the inner tube, the clot removal device being deployable in a first state to a radially expanded configuration.

2. The catheter of claim 1, further including an outer tube arranged to surround and constrain the clot removal device about the inner tube in a second state prior to its deployment to the first state, the catheter body and clot removal device in the second state being passable through the clot.

3. The catheter of claim 2, wherein the inner and outer tubes are relatively axially displaceable to cause the clot removal device to transition between the first and second states.

4. The catheter of claim 3, wherein the inner and outer tubes extend co-axially substantially the entire length of an insertion portion of the catheter body.

5. The catheter of claim 4, further including a handle attached to a proximal end of the insertion portion, and an actuator on the handle for proximally displacing the outer tube with respect to the inner tube.

6. The catheter of claim 5, further including an infusion port provided on the handle in fluid communication with an annular space defined between the inner and outer tubes.

7. The catheter of claim 6, wherein the infusion port is mounted to a slide that is axially displaceable on the handle, and wherein the catheter body outer tube is attached to a distal end of the slide to receive fluid from the infusion port.

8. The catheter of claim 2, further including a distal tip attached to a distal end of the inner tube, the distal tip having a tapered distal surface defining the distal end of the catheter body, the tapered distal surface facilitating passage of the catheter body through the clot.

9. The catheter of claim 8, wherein the distal tip defines a proximal mouth for receiving a short length of the outer tube, wherein the distal end of the outer tube is thereby prevented from catching on the clot as the catheter body passes therethrough.

10. The catheter of claim 9, wherein the outer tube is relatively retractable in the proximal direction with respect to the inner tube, the clot removal device radially expanding into the first state in a region between the retracted outer tube and the distal tip.

11. The catheter of claim 10, wherein the clot removal device has a proximal end and a distal end, the distal end being attached to the inner tube and the proximal end being free to slide axially over the inner tube, the proximal end of the clot removal device being axially displaced away from the distal end within the outer tube to longitudinally stretch and radially constrict the device in the second state.

12. The catheter of claim 11, wherein the clot removal device comprises a plurality of separate wires each attached at their distal ends to the inner tube and being looped about the inner tube at their proximal ends.

13. The catheter of claim 11, further including a sliding marker band disposed about the inner tube and configured to slide with the proximal end of the clot removal device to indicate the transition between the first and second states.

14. The catheter of claim 13, further including a fixed marker band attached about the inner tube distally with respect to the clot removal device, the relative spacing between the fixed marker band and the sliding marker band indicating the transition between the first and second states.

15. The catheter of claim 1, wherein the catheter further comprises a handle and an insertion portion of the catheter body extending distally from handle, the insertion portion being defined by the inner tube and a co-axial outer tube extending substantially to the distal end of the catheter body, the clot removal device being radially constricted about the inner tube in a second state prior to its deployment to the first state, the catheter body and clot removal device in the second state being passable through the clot, wherein the inner and outer tubes are relatively axially displaceable to cause the clot removal device to transition between the first and second states.

16. The catheter of claim 15, wherein the insertion portion becomes more flexible in a distal direction from the handle.

17. The catheter of claim 16, wherein the catheter body has a size of between about 1-5 French at its distal end.

18. The catheter of claim 16, wherein both the inner and outer tubes become more flexible in a distal direction from the handle.

19. The catheter of claim 18, wherein both the inner and outer tubes include discrete segments that become more flexible in a distal direction from the handle.

20. The catheter of claim 19, wherein at least one of the inner and outer tubes includes a reinforced segment adjacent the handle.

21. The catheter of claim 15, further including an actuator on the handle for proximally displacing the outer tube with respect to the inner tube.

22. The catheter of claim 21, further including an infusion port provided on the handle in fluid communication with an annular space defined between the inner and outer tubes.

23. The catheter of claim 22, wherein the infusion port is mounted to a slide that is axially displaceable on the handle.

24. The catheter of claim 23, further including an inner hypotube extending substantially the length of the handle and attached at its distal end to the catheter body inner tube, and a guidewire introducer on a proximal end of the handle leading to the lumen of the inner hypotube, wherein the slide includes a throughbore receiving the hypotube.

25. The catheter of claim 24, wherein the infusion port is in fluid communication with the throughbore, and wherein the catheter body outer tube is attached to a distal end of the slide co-axially with respect to the throughbore for receiving fluid from the infusion port.

26. The catheter of claim 1, wherein the clot removal device has a proximal end and a distal end, the distal end being attached to the inner tube and the proximal end being free to slide axially over the inner tube, the proximal end of the clot removal device being axially displaced away from the distal end within the outer tube to longitudinally stretch and radially constrict the device in a second state prior to its deployment to the first state, the clot removal device in the second state being passable through the clot.

27. The catheter of claim 26, further including a sliding marker band disposed about the inner tube and configured to slide with the proximal end of the clot removal device to indicate the transition between the first and second states.

28. The catheter of claim 27, further including a fixed marker band attached about the inner tube distally with respect to the clot removal device, the relative spacing between the fixed marker band and the sliding marker band indicating the transition between the first and second states.

29. The catheter of claim 26, wherein the clot removal device comprises a plurality of separate wires each attached at their distal ends to the inner tube and being looped about the inner tube at their proximal ends, the wires being spring biased to radially expand if unconstrained, the catheter body further including an outer tube arranged to surround and constrain the clot removal device about the inner tube in the second state, the inner and outer tubes being relatively axially displaceable to release the wires.

30. The catheter of claim 29, wherein the separate wires are helically wound about the inner tube, the spring-biased helical wires forming a radially expanded nest configuration upon their release from within the outer tube.

31. A system including the catheter of claim 1, and further including a guidewire received in the guidewire lumen and having a length sufficient to extend from the proximal end of the catheter body and project from the distal end.

32. The system of claim 31, wherein the guidewire is an infusion guidewire.

33. An embolectomy catheter for removing a blood clot or other such obstructive matter from a blood vessel, the catheter comprising:

an elongate flexible catheter body having a proximal end, a distal end, an inner tube, and an outer tube terminating just short of a distal end of the catheter body;

a clot removal device on the inner tube, the clot removal device being initially collapsed and constrained in its collapsed configuration by a portion of the outer tube;

a distal tip of the catheter body located on the inner tube and adapted to pass through a blood clot to be removed; and

wherein the outer tube is axially retractable to remove the constraint on the clot removal device such that the clot removal device may radially expand to a deployed configuration.

34. The catheter of claim 33, wherein the outer tube extends distally within a proximal mouth of the distal tip prior to being retracted.

35. The catheter of claim 33, wherein the inner tube is reinforced along its entire length.

36. The catheter of claim 35, wherein the inner tube is more flexible at its distal end than at its proximal end.

37. The catheter of claim 36, wherein the inner tube includes a proximal reinforced segment and a distal reinforced segment, and wherein the proximal segment has reinforcement of higher density than in the distal segment.

38. The catheter of claim 33, wherein the catheter body becomes more flexible in a direction from the proximal end to the distal end.

39. The catheter of claim 38, wherein the catheter body has a size of between about 1-5 French at its distal end.

40. The catheter of claim 38, wherein both the inner and outer tubes include discrete segments that become more flexible in a direction from the proximal end to the distal end.

41. The catheter of claim 40, wherein the inner tube is reinforced along its entire length, and includes a proximal reinforced segment and a distal reinforced segment, and wherein the proximal segment has reinforcement of higher density than in the distal segment.

42. The catheter of claim 38, wherein a portion of the outer tube that constrains the clot removal device in its collapsed configuration has a substantially lower column strength than a portion of the inner tube about which the clot removal device is mounted.

43. The catheter of claim 33, further including a handle attached to a proximal end of the insertion portion, and an actuator on the handle for proximally displacing the outer tube with respect to the inner tube.

44. The catheter of claim 43, further including an infusion port provided on the handle in fluid communication with an annular space defined between the inner and outer tubes.

45. The catheter of claim 44, wherein the infusion port is mounted to a slide that is axially displaceable on the handle.

46. The catheter of claim 43, further including a slide that is axially displaceable on the handle and an inner hypotube extending substantially the length of the handle and attached at its distal end to the catheter body inner tube, and a guidewire introducer on a proximal end of the handle leading to the lumen of the inner hypotube, wherein the slide includes a throughbore receiving the hypotube.

47. The catheter of claim 33, wherein the clot removal device has a proximal end and a distal end, the distal end being attached to the inner tube and the proximal end being free to slide axially over the inner tube, the proximal end of the clot removal device being axially displaced away from the distal end within the outer tube to longitudinally stretch and radially constrict the device in a second state prior to its deployment to the first state, the clot removal device in the second state being passable through the clot.

48. The catheter of claim 47, further including a sliding marker band disposed about the inner tube and configured to slide with the proximal end of the clot removal device to indicate the transition between the first and second states.

49. A system including the catheter of claim 33, wherein the inner tube defines a guidewire lumen sized to receive a guidewire therein, the guidewire lumen being open on its distal end to permit the guidewire so received to project distally from the distal end of the catheter body, and further including a guidewire received in the guidewire lumen and having a length sufficient to extend from the proximal end of the catheter body and project from the distal end.

50. The system of claim 49, wherein the guidewire is an infusion guidewire.