KINETIC STENT

• US 20020062148A1
• Filed: 02/26/1997
• Published: 05/23/2002
• Est. Priority Date: 02/26/1997
• Status: Active Grant

• Current Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Original Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Inventors: HART, CHARLES C.
• Granted Patent: US 6,582,472 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/04 Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts A61F2/18, A61F2/20 take precedence; devices, other than stent-grafts, providing patency to, or preventing collapsing of, tubular structures of the body other than stent-grafts, e.g. stents A61F2/82; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61M 27/008 pre-shaped, for use in the urethral or ureteral tract

Abstract

The disclosed stent is formed of an elongate, flexible duct having a very thin wall and a preformed diameter, length, and shape. The stent is constructed of a woven tubular structure of multiple strands or elements. The woven tubular structure is thermally set to a predetermined diameter and length, so that the “at rest” or natural condition of the tubular structure is predictable. A retention or holding member can be formed at one or both of the ends of the stent. This retention member can be reduced in diameter for insertion into the body passage. The woven tubular structure provides a path for fluids to flow in and around the stent, while a patent lumen is being developed. The woven tubular structure allows the stent to be extended or stretched over a guidewire or other noncompressive member, to thereby reduce the diameter of the stent for insertion of the stent into a body passage.

Claims

1. A stent for use in a body passage/comprising:

an expandable tube having a proximal tube end, a distal tube end, and a lumen extending from the proximal tube end to the distal-tube end, the expandable tube being configurable between a large-diameter relaxed state and a small-diameter tension state, the proximal tube end and the distal tube end being separated by a predetermined distance when the expandable tuber is in the large-diameter relaxed state, and the proximal tube end and the distal tube end being separated by a second distance, which is larger than the predetermined distance, when the expandable tube is in the small-diameter tension state; and

a retention member integrally formed with the expandable tube and extending proximally from the distal tube end, the retention member having a large-diameter relaxed shape and a small-diameter tension shape, and having a retention-feature diameter in the large-diameter relaxed shape which is greater than an expandable-tube diameter of the expandable tube when the expandable tube is in the large-diameter relaxed state.

2. The stent as recited in claim 1, further comprising activating means adapted for increasing a distance between the proximal tube end and the distal tube end, to thereby change the expandable tube from the large-diameter relaxed state to the small-diameter tension state.

3. The stent as recited in claim 2, the activating means further being adapted for changing the retention member from the large-diameter relaxed shape to the small-diameter tension shape, by increasing a distance between the proximal tube end and the distal tube end.

4. The stent as recited in claim 3, the activating means comprising:

a compression tube adapted for fitting within the lumen and for contacting the distal tube end, the compression tube further being adapted for applying a distal force onto the distal tube end when a proximal force is applied to the proximal tube end.

5. The stent as recited in claim 4, the application of both the distal tube force to the distal tube end, and the proximal force to the proximal tube end changing the expandable tube from the large-diameter relaxed state to the small-diameter tension state, and

a removal of both the distal force from the distal tube end and the proximal force from the proximal tube end changing the expandable tube from the small-diameter tension state to the large-diameter relaxed state.

6. A stent for use in a body passage, comprising:

a woven tube having a proximal tube end, a distal tube end, and a lumen extending from the proximal tube end to the distal tube end; and

a retention member integrally formed with the woven tube and extending proximally from the distal tube end, the retention member having a diameter which is greater than a diameter of the woven tube.

7. The stent as recited in claim 6, the woven tube being configurable between a insertion configuration having a long-length and a small diameter, and a stent configuration having a short-length and a large-diameter.

8. A stent for use in a body passage, comprising:

an expandable tube having a diameter, a proximal tube end, a distal tube end, and a lumen extending from the proximal tube end to the distal tube end; and

activating means adapted for decreasing the diameter of the expandable tube by increasing a distance between the proximal tube end and the distal tube end.

9. The stent as recited in claim 8, the expandable tube comprising a braided thermoplastic material, and

the activating means comprising means for applying tension between the proximal tube end and the distal tube end, to thereby increase the distance between the proximal tube end and the distal tube end.

10. The stent as recited in claim 8, the activating means being adapted for fitting within the lumen.

11. A stent, comprising:

a stent body formed of a braided material; and

an enlarged-diameter retention member adjacent to the stent body and integrally formed with the stent body of the braided material.

12. The retention member as recited in claim 11, the enlarged-diameter retention member being disposed near a distal end of the stent.

13. The retention member as recited in claim 12, the enlarged-diameter retention member comprising a cone shape.

14. The stent as recited in claim 12, further comprising:

a rigid collar at a distal end of the cone-shaped retention member, the rigid collar defining an aperture; and

a compression sleeve adapted for fitting within the stent body, and for contacting the rigid collar.

15. The stent as recited in claim 14, the stent being configurable into the insertion configuration by application of distal force on the rigid collar by the compression sleeve, and being configurable into the stent configuration by removal of the distal force from the rigid collar.

16. The stent as recited in claim 15, further comprising a guidewire adapted for fitting within the stent body and through the aperture.

17. The retention member as recited in claim 13, further comprising a plurality of convolutions disposed on the stent body.

18. The retention member as recited in claim 11, the enlarged-diameter retention member forming a convolution, which is disposed near an intermediate portion of the stent.

19. The retention member as recited in claim 18, further comprising a plurality of convolutions disposed adjacent to the convolution.

20. The retention member as recited in claim 19, the plurality of convolutions covering a majority of the stent.

21. The stent as recited in claim 11, the stent being configurable between an insertion configuration having a long-length and a small diameter, and a stent configuration having a short-length and a large-diameter.

22. The stent as recited in claim 21, a ratio of a diameter of the enlarged-diameter retention member to a diameter of the stent body, in the stent configuration, being approximately equal to a ratio of a diameter of the enlarged-diameter retention member to a diameter of the stent body, in the insertion configuration.

24. The tube as recited in claim 23, the tube further comprising:

a wall formed of a braided material; and

a retention member formed in the wall of braided material, the retention member comprising a radially-increasing portion and a radially-decreasing portion.

25. The tube as recited in claim 24, the radially-increasing portion extending substantially perpendicularly to a portion of the wall around a circumference of the wall, and

the radially-decreasing portion comprising a cone shape having an axis parallel with an axis of the tube.

27. The retention member as recited in claim 26, the radially-increasing portion and the radially-decreasing portion forming a cone shape having an axis parallel with an axis of the tubular trunk.

28. The retention member as recited in claim 27, further comprising a plurality of convolutions disposed on the stent.

29. The retention member as recited in claim 26, the radially-increasing portion and the radially-decreasing portion together forming a convolution, which is disposed at an intermediate portion of the stent.

30. The retention member as recited in claim 29, further comprising a plurality of convolutions disposed adjacent to the convolution.

31. The retention-member as recited in claim 30, the plurality of convolutions covering a majority of the stent.

23. A tube operable as a stent, the tube comprising:

a proximal tube end;

a distal tube end;

a lumen extending from the proximal tube end to the distal tube end; and

a collar disposed at the distal end, the collar being adapted for receiving a distal force from within the lumen, the tube being transformable from a short-length, large-diameter stent configuration to a long-length, small-diameter insertion configuration when the distal force is applied to the collar, and the tube being transformable back into the short-length, large-diameter stent configuration when the distal force is removed.

26. A retention member for use in combination with a stent, comprising:

a tubular trunk formed of a braided material;

a radially-increasing portion formed in the braided material and disposed adjacent to and integral with the tubular trunk, the radially-increasing portion extending substantially perpendicularly to a surface of the tubular trunk around a circumference of the tubular trunk; and

a radially-decreasing portion formed in the braided material and disposed adjacent to and integral with the tubular trunk.

32. A stent, comprising:

a radially-contractible tube having a proximal tube end, a distal tube end, a diameter, and a lumen extending from the proximal tube end to the distal tube end; and

an actuator disposed within the lumen for increasing a distance between the proximal tube end and the distal tube end, to thereby reduce the diameter of the radially-contractible tube.

33. A method of accessing a body passage, comprising the following steps:

converting a stent into a long-length, small-diameter insertion configuration by applying tension between a proximal end of the stent and a distal end of the stent, to thereby increase a distance between the proximal end of the stent and the distal end of the stent;

inserting the stent into a body passage of a patient;

moving the stent through the body passage of the patient to a desired location; and

converting the stent into a small-length, large-diameter stent configuration by removing the tension to thereby decrease the distance-between the proximal end of the stent and the distal end of the stent.

35. The method as recited in claim 34, the forming tool comprising a cone-shaped portion near a distal end of the cylindrical body, and

the second diameter corresponding to a diameter of a guidewire.

36. The method as recited in claim 34, the irradiating step being preceded by a step of folding a portion of the woven tubular structure, located proximally of the cone-shaped portion, proximally upon the cylindrical body to thereby form a retention member.

37. The method as recited in claim 34, the forming tool comprising a cylindrical mandrel with both a first cone-shaped portion near a distal end of the cylindrical mandrel and a second cone-shaped portion near a proximal end of the cylindrical mandrel, and the irradiating step being preceded by the following steps:

folding a portion of the woven tubular structure, located proximally of the first cone-shaped portion, proximally upon the mandrel to thereby form a first retention member; and

folding a portion of the woven tubular structure, located distally of the second cone-shaped portion, distally upon the mandrel to thereby form a second retention member.

38. The method as recited in claim 37, the removing step being followed by a step of cutting the resulting structure in half, to thereby bisect the resulting structure into two stents.

40. The method as recited in claim 39, the inserting step being preceded by a step of converting the stent into a long-length, small-diameter insertion configuration by increasing a distance between a proximal end of the stent and a distal end of the stent.

41. The method as recited in claim 40, the step of iteratively increasing a diameter of the stent including a step of converting the-stent into a small-length, large-diameter stent configuration by decreasing a distance between a proximal end of the stent and a distal end of the stent.

34. A method of making an stent, which is transformable between a large-diameter configuration and a small-diameter configuration, the stent being transformable from the large-diameter configuration to the small-diameter configuration upon application from a compression sleeve of a distal force onto a distal end of the stent, the method comprising the following steps:

providing a woven tubular structure;

placing the woven tubular structure over a forming tool, the forming tool comprising a cylindrical body having a first diameter corresponding to the large-diameter configuration, and having a second diameter that is smaller than a diameter of the compression sleeve;

irradiating the woven tubular structure with thermal energy, to thereby set a portion of the woven tubular structure at the first diameter and to set a distal end of the woven tubular structure at the second diameter; and

removing a resulting structure from the forming tool.

39. A method of iteratively increasing a diameter of a lumen of a body passage, comprising the following steps:

inserting a stent into a body passage of a patient;

moving the stent through the body passage of the patient to a desired location; and

iteratively increasing a diameter of the stent, a first iterative increase of the diameter of the stent resulting in the diameter, and a second iterative increases of the diameter of the stent resulting in the diameter of the lumen increasing to a second enlarged diameter which is greater than the first enlarged diameter.