Retrieval systems and methods for use thereof
The devices and methods described herein relate to improved structures for removing obstructions from body lumens. Such devices have applicability in through-out the body, including clearing of blockages within the vasculature, by addressing the frictional resistance on the obstruction prior to attempting to translate and/or mobilize the obstruction within the body lumen.
1. A medical device for retrieving a clot from within a vessel lumen, the device comprising:
a delivery wire sized for advancement through a blood vessel, the delivery wire having a distal region and a proximal region;
a stent coupled to the distal region of the delivery wire;
an inverting funnel having a first end portion coupled to the distal region of the delivery wire and a free second end portion, the funnel having (a) a first position in which the first end portion is distal of the second end portion, and (b) a second position in which the second end portion is distal of the first end portion such that the funnel surrounds at least a portion of the stent,
wherein, when the device is positioned within the vessel lumen such that the stent and the funnel are in an expanded state and the funnel is in the first position, proximal movement of the delivery wire causes the funnel to move from the first position towards the second position.
2. The medical device of claim 1 , wherein the funnel is self-expanding.
3. The medical device of claim 1 , wherein the funnel is a braid.
4. The medical device of claim 3 , wherein the braid is formed of a plurality of wires that are drawn filled tubes.
5. The medical device of claim 3 , wherein the braid is formed of a plurality of wires that are drawn filled tubes having a platinum core.
6. The medical device of claim 3 , wherein the braid is formed of 48-96 wires.
7. The medical device of claim 3 , wherein the braid is formed of wires having a diameter of about 0.001 inches to about 0.002 inches.
8. The medical device of claim 1 , wherein the funnel has a single layer.
9. The medical device of claim 1 , wherein the funnel has multiple layers.
10. The medical device of claim 1 , wherein the funnel is attached directly to the stent.
11. The medical device of claim 1 , wherein the first end portion of the funnel is fixed relative to a proximal terminus of the stent.
12. The medical device of claim 1 , wherein the funnel and the stent are fixed to the delivery wire at a common junction.
13. The medical device of claim 1 , wherein the first end portion of the funnel is coupled to the delivery wire proximal of the stent.
14. The medical device of claim 1 , wherein the first end portion of the funnel is fixed to the delivery wire at a location proximal of and spaced apart from the stent.
15. The medical device of claim 1 , wherein a portion of the funnel has a pre-set shape.
16. The medical device of claim 1 , wherein the funnel is slidable relative to the delivery wire.
17. The medical device of claim 1 , wherein the funnel is slidable relative to the delivery wire and the stent.
18. The medical device of claim 1 wherein, the funnel includes a funnel wall extending between the first end portion and the second end portion, and wherein a portion of the funnel wall extends distally beyond the first end portion when the funnel is expanded into the first position prior to proximal movement of the delivery wire.
19. The medical device of claim 1 , wherein the stent comprises a stentriever.
20. The medical device of claim 1 , wherein the delivery wire is sized for advancement through a microcatheter.
21. The medical device of claim 1 , wherein the funnel is configured to invert in conveyor belt fashion to cover the stent.
22. The medical device of claim 1 , wherein the funnel is configured to be held in place during inversion by frictional force against the blood vessel wall.
23. A medical device for retrieving a clot from within a vessel lumen, the device comprising:
a delivery wire sized for advancement through a blood vessel, the delivery wire having a distal region and a proximal region;
a stent having a proximal portion fixed to the distal region of the delivery wire and a distal portion;
a braid having a fixed end and an opposing free open end, the fixed end fixed to the delivery wire at or proximal to the proximal portion of the stent,
wherein, when the device is positioned within the vessel lumen such that the stent and the braid are in an expanded state and the open end of the braid is proximal of the fixed end, proximal movement of the delivery wire causes the stent to move proximally while the braid engages the vessel wall such that friction of the braid against the vessel wall causes the open end of the braid to invert over at least a portion of the stent so that the open end of the braid is distal to the fixed end, thereby covering at least a portion of the stent.
24. The medical device of claim 23 , wherein the braid is self-expanding.
25. The medical device of claim 23 , wherein the braid is formed of a plurality of wires that are drawn filled tubes.
26. The medical device of claim 23 , wherein the braid is formed of a plurality of wires that are drawn filled tubes having a platinum core.
27. The medical device of claim 23 , wherein the braid is formed of 48-96 wires.
28. The medical device of claim 23 , wherein the braid is formed of wires having a diameter of about 0.001 inches to about 0.002 inches.
29. The medical device of claim 23 , wherein the braid has a single layer.
30. The medical device of claim 23 , wherein the braid has multiple layers.
31. The medical device of claim 23 , wherein the braid is attached directly to the stent.
32. The medical device of claim 23 , wherein the fixed end of the braid is fixed relative to a proximal terminus of the stent.
33. The medical device of claim 23 , wherein the braid and the stent are fixed to the delivery wire at a common junction.
34. The medical device of claim 23 , wherein the fixed end of the braid is coupled to the delivery wire proximal of the stent.
35. The medical device of claim 23 , wherein the fixed end of the braid is fixed to the delivery wire at a location proximal of and spaced apart from the stent.
36. The medical device of claim 23 , wherein a portion of the braid has a pre-set shape.
37. The medical device of claim 23 , wherein the braid is slidable relative to the delivery wire.
38. The medical device of claim 23 , wherein the braid is slidable relative to the delivery wire and the stent.
39. The medical device of claim 23 , wherein the braid includes a braid wall extending between the fixed end and the open end, and wherein a portion of the braid wall extends distally beyond the fixed end when the braid is expanded into the first position prior to proximal movement of the delivery wire.
40. The medical device of claim 23 , wherein the stent comprises a stentriever.
41. The medical device of claim 23 , wherein the delivery wire is sized for advancement through a microcatheter.
42. The medical device of claim 23 , wherein the braid is configured to invert in conveyor belt fashion to cover the stent.
43. The medical device of claim 23 , wherein the braid is configured to be held in place during inversion by frictional force against the blood vessel wall.
44. The medical device of claim 23 , wherein the fixed end of the braid is closed.
45. A method for retrieving a clot from within a vessel lumen of a patient using a retrieval device, the method comprising:
positioning the retrieval device within the vessel lumen at or near the clot, wherein the retrieval device is coupled to a distal portion of a delivery wire, the retrieval device including (i) a stent coupled to the delivery wire and (ii) a funnel having a first end portion coupled to the delivery wire and a free second end portion;
expanding the retrieval device within the lumen into a first configuration such that at least a portion of the funnel expands into contact with the vessel wall and the coupled first end portion of the funnel is distal of the free second end portion of the funnel;
securing at least a portion of the clot via the stent,
pulling the delivery wire proximally, thereby transforming the retrieval device into a second configuration in which the second end portion of the funnel is distal of the first end portion such that the funnel surrounds at least a portion of the stent; and
withdrawing the retrieval device and the at least a portion of the clot from the patient.
46. The method of claim 45 , wherein pulling the stent proximally suffices to invert the funnel and thereby cover the stent.
47. The method of claim 45 , wherein the funnel is self-expanding.
48. The method of claim 45 , wherein the funnel is a braid.
49. The method of claim 45 , wherein the funnel has a single layer.
50. The method of claim 45 , wherein the funnel has multiple layers.
51. The method of claim 45 , wherein the funnel is attached directly to the stent.
52. The method of claim 45 , wherein the first end portion of the funnel is fixed relative to a proximal terminus of the stent.
53. The method of claim 45 , wherein the funnel and the stent are fixed to the delivery wire at a common junction.
54. The method of claim 45 , wherein the first end portion of the funnel is coupled to the delivery wire proximal of the stent.
55. The method of claim 45 , wherein the first end portion of the funnel is fixed to the delivery wire at a location proximal of and spaced apart from the stent.
56. The method of claim 45 , wherein a portion of the funnel has a pre-set shape.
57. The method of claim 45 , further comprising sliding the funnel along the delivery wire.
58. The method of claim 45 , further comprising sliding the funnel along the delivery wire relative to the stent.
59. The method of claim 45 , wherein the funnel includes a funnel wall extending between the first end portion and the second end portion, and wherein a portion of the funnel wall extends distally beyond the first end portion when retrieval device is in the first configuration prior to proximal movement of the delivery wire.
60. The method of claim 45 , wherein the stent comprises a stentriever.
61. The method of claim 45 , further comprising advancing the delivery and retrieval device through a microcatheter.
62. The method of claim 45 , wherein pulling the delivery wire proximally includes inverting the funnel.
63. The method of claim 62 , wherein the funnel is configured to be held in place during inversion by frictional force against the blood vessel wall.
64. The method of claim 45 , wherein the first end portion of the funnel is closed.