Ureteral backstop filter and retrieval device

• US 20050043756A1
• Filed: 07/28/2004
• Published: 02/24/2005
• Est. Priority Date: 07/31/2003
• Status: Active Grant

• Current Assignee: Cook Medical Technologies, LLC (Cook Group Incorporated), Nordson Corporation
• Original Assignee: Cook Ireland Limited (Cook Group Incorporated), Vance Products Incorporated (Cook Group Incorporated)
• Inventors: Andrews, Marvin O., Diamant, Valery, Lavelle, Shay, Yasko, Nadezda, Fischer, Frank J. Jr., Ryan, Walter N., Khachin, Stepan, Khachin, Vladimir
• Granted Patent: US 7,731,722 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 17/32056 Surgical snare instruments for removing or smashing calculi A61B2017/2212; tonsillotomes A61B17/26
• CPC Class Codes: A61B 2017/2212 having a closed distal end, e.g. a loop
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

A retrieval device for use in renal, biliary, vascular or other systems of a body includes a collapsible basket in a narrow sheath. A surgeon advances the device beyond an object to be removed from a body, such as a kidneystone, a gallstone, or a thrombus. The surgeon then retracts the sheath or advances the basket from the sheath. The basket deploys only to one side of the sheath. In some embodiments, the periphery of the basket has a flex point to enable the basket to easily collapse into the sheath. If the sheath is adjacent a body vessel, such as a blood vessel or a ureter, the sheath remains adjacent the wall, while the device deploys in such a manner as to seal against the walls of the vessel and block the flow of fragments, emboli, thrombi, or other undesirable objects.

Claims

1. A medical retrieval device, comprising:

a control rod;

a basket comprising a plurality of loops attached to the control rod, the loops interleaved and formed into an atraumatic periphery of the basket; and

a sheath, wherein when the sheath is retracted or the basket is extended, the basket asymmetrically projects in one direction from the sheath.

2. The device of claim 1, wherein the device further comprises an echogenic surface or radiopaque component.

3. The device of claim 1, wherein the basket has a proximal end and a distal end, the proximal end gathering a majority of the loops, and the distal end at about 180°

from the proximal end, and wherein the periphery includes a flex point comprising a bend in a loop or a link for two twisted loops, and the flex point is near the distal end.

4. The device of claim 1, wherein the basket is made by forming a smaller loop in a first loop kinklessly and continuously around a second loop.

5. The device of claim 1, wherein the loops are secured to the control rod with at least one of a crimp, a weld joint, a braze joint, a solder joint, and an adhesive.

6. The device of claim 1, further comprising a removable handle.

7. The device of claim 1, wherein the basket further comprises a mesh connected to the loops.

8. The device of claim 1, wherein the basket further comprises a leg of wire formed about at least one loop.

9. The device of claim 1, further comprising a removable handle having a first end and a second end, the first end attached to the sheath and the second end attached to the control rod.

10. The device of claim 1, wherein the deployed basket is in a form selected from the group consisting of a concave hemisphere, a convex hemisphere, a cylinder, a sphere, a cone, a saucer, an umbrella, and an irregular shape.

11. The device of claim 1, further comprising at least one stop on the control rod or the sheath.

12. The device of claim 1, further comprising a radiopaque marker.

13. The device of claim 1, wherein the loops are made from a material selected from the group consisting of Nitinol and a shape memory alloy.

14. The device of claim 1, further comprising a filiform tip formed from at least one loop or one leg attached to the control rod.

15. The device of claim 1, further comprising a connector between the loops and the control rod.

16. The device of claim 1, further comprising a connector with a notch between the loops and the control rod.

61. The winding tool of claim 7, wherein the basket portion that forms an atraumatic periphery is adapted to form a flex point on the periphery.

17. A method of making a collapsible retrieval device, the method comprising:

forming a plurality of loops into a tipless atraumatic basket, in which the loops project from only one side of the basket; and

attaching ends of the loops to a control rod.

18. The method of claim 17, further comprising forming a flex point on a periphery of the basket, wherein the flex point is formed by bending or deforming a wire, or by linking and twisting two loops together.

19. The method of claim 18, wherein the basket has a proximal end and a distal end, the proximal end gathering a majority of the loops, and the distal end at about 180°

from the proximal end, and wherein the flex point is formed near the distal end by bending or deforming a wire, or by linking and twisting two loops together.

20. The method of claim 17, further comprising heat treating the basket so that the basket is in a state of stress when the basket is in the sheath and the basket is in a relaxed state when the basket is deployed from the sheath.

21. The method of claim 17, further comprising attaching the control rod to a removable handle.

22. The method of claim 17, further comprising attaching the loops to the control rod with a connector having a notch.

23. The method of claim 17, further comprising attaching a mesh to the loops.

24. The method of claim 17, wherein the loops are formed from a superelastic alloy.

25. The method of claim 17, in which the basket is formed by at least two wires twisted together.

26. The method of claim 17, further comprising forming an echogenic surface on at least one component of the retrieval device.

27. The method of claim 17, in which the basket is formed by at least two wires twisted separately and joined at a joint.

28. The method of claim 17, wherein the loops are formed into a basket by kinklessly and continuously forming a smaller loop in a first loop around a second loop.

29. The method of claim 17, further comprising adding at least one stop to the control rod or the sheath.

30. The method of claim 17, wherein at least one component of the device is radiopaque.

31. The method of claim 17, further comprising forming a filiform tip at a distal point on the device.

32. A ureteral backstop filter, comprising:

a control rod further comprising an attaching portion and a control portion;

a basket further comprising a plurality of loops attached to the control rod, the loops interleaved and formed into an atraumatic periphery of the basket, the periphery further comprising a flex point; and

a sheath containing the basket, wherein when the sheath is retracted or the loops are extended, the basket projects perpendicularly from the sheath.

33. The filter of claim 32, wherein the flex point comprises a bend in a loop or a link for two twisted loops.

34. The filter of claim 32, wherein the basket has a proximal end and a distal end, the proximal end gathering a majority of the loops, and the distal end at about 180°

from the proximal end, and wherein the flex point comprises a bend in a loop or a link for two twisted loops, and the flex point is near the distal end.

35. The filter of claim 32, wherein at least one component of the device is radiopaque or echogenic.

36. The filter of claim 33, wherein the attaching portion is radiopaque.

37. The filter of claim 33, wherein the loops are made from a material selected from the group consisting of Nitinol and a shape memory alloy.

38. The filter of claim 33, wherein the loops are made from a superelastic alloy and are in a relaxed condition when the basket is deployed.

39. The filter of claim 33, wherein the loops are secured to the control rod with at least one of a crimp, a weld joint, a solder joint, a braze joint, and an adhesive.

40. The filter of claim 33, wherein the basket further comprises a mesh attached to at least one of the loops.

41. The filter of claim 33, further comprising a removable handle.

42. The filter of claim 33, wherein a cross-section of the basket has a shorter axis and a longer axis.

43. The filter of claim 33, wherein the loops are formed into a basket by kinklessly and continuously forming a smaller loop in a first loop around a second loop.

44. The filter of claim 33, further comprising a stop on the control rod or the sheath.

45. The filter of claim 33, further comprising a radiopaque component.

46. The filter of claim 33, wherein the atraumatic periphery of the basket is formed by at least two wires that have been linked and twisted.

47. The filter of claim 33, wherein the atraumatic periphery of the basket is formed by at least one wire that has been bent.

48. A retrieval device, comprising:

a control rod;

a plurality of superelastic wire loops attached to the control rod, the wire loops formed into a tipless basket with an atraumatic periphery;

a filiform formed from at least a portion of the superelastic wire loops; and

a sheath, wherein when the sheath is retracted or the loops are extended, the basket projects perpendicularly from the sheath, the loops being in a relaxed condition when outside the sheath.

49. The retrieval device of claim 48, wherein the periphery further comprises a flex point comprising a bend in a loop or a link for two twisted loops.

50. The filter of claim 48, further comprising a removable handle.

51. The filter of claim 48, wherein the basket further comprises a filter mesh connected to at least one of the wire loops.

52. The filter of claim 48, wherein the wire loops are formed into a basket by winding a first loop with a smaller loop, and winding the smaller loop around a second loop.

53. The filter of claim 48, further comprising a leg attached to the control rod and formed into the basket by winding the leg around at least one loop.

54. The filter of claim 48, further comprising a stop on the control rod or the sheath.

55. The filter of claim 48, further comprising at least one component that is radiopaque or echogenic.

56. The filter of claim 48, further comprising a filiform tip.

57. A tool for winding an asymmetric medical retrieval device, the tool comprising:

a basket portion comprising grooves for placing a plurality of wires for a tipless asymmetric basket, wherein the wires extend from only one side of the basket, wherein at least two wires form an atraumatic periphery of the basket; and

an axial portion connected to the basket portion, the axial portion extending from the basket portion to a control portion.

58. The winding tool of claim 57, further comprising a twisting portion for twisting the wires in the axial portion.

59. The winding tool of claim 57, wherein the basket portion comprises a longer axis and a perpendicular shorter axis.

60. The winding tool of claim 57, wherein the basket portion comprises an aspect ratio of from about 55/45 to about 60/40.