TUBULAR STRUCTURE AND METHOD FOR MAKING THE SAME

• US 20120271403A1
• Filed: 04/21/2011
• Published: 10/25/2012
• Est. Priority Date: 04/21/2011
• Status: Active Grant

• Current Assignee: St. Jude Medical Cardiology Division Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: AGA Medical Corporation (Abbott Laboratories Incorporated)
• Inventors: Gries, Sara Jane
• Granted Patent: US 8,511,214 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 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: B32B 1/08 Tubular products
• CPC Class Codes: D04C 1/06 Braid or lace serving particular purposes
• CPC Class Codes: D04C 3/48 Auxiliary devices
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents
• CPC Class Codes: Y10T 428/12007 Component of composite having metal continuous phase interengaged with nonmetal continuous phase
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/1369 Fiber or fibers wound around each other or into a self-sustaining shape [e.g., yarn, braid, fibers shaped around a core, etc.]

Abstract

A tubular structure and method for making a tubular structure are provided, where the tubular structure includes at least one layer of braided strands. In general, at least one portion of the braided strands exhibits a braid pattern of crests and troughs (e.g., a wave pattern, which may include sinusoidal, square, and/or sawtooth waves) along a length of the tubular structure. The wave pattern can be created by rotating the mandrel onto which the tubular structure is braided during the braiding process, such as by angularly oscillating the mandrel about its longitudinal axis or about its transverse axis. As a result, the tubular structures may have increased radial strength, collapse resistance, torque transmission, column strength, and kink resistance. The tubular structures may be used in medical devices, such as stent-grafts, as well as in other medical and non-medical devices, such as in hoses, tubing, filters, and other devices.

Claims

1. A method of braiding a plurality of strands into a tubular structure comprising:

braiding at least a first set of strands and at least a second set of strands onto a mandrel;

moving the mandrel along a longitudinal axis of the mandrel as the first and second sets of strands are being braided onto the mandrel; and

rotating the mandrel as the first and second sets of strands are being braided onto the mandrel.

2. The method of claim 1, wherein the step of rotating the mandrel comprises rotating the mandrel about the longitudinal axis.

3. The method of claim 1, wherein the step of rotating the mandrel comprises rotating the mandrel about a transverse axis that is substantially perpendicular to the longitudinal axis.

4. The method of claim 1, wherein the step of rotating the mandrel as the first and second sets of strands are being braided onto the mandrel results in at least a portion of the braided strands exhibiting a wave pattern that includes crests and troughs along a length of the tubular structure.

5. The method of claim 1, wherein the step of braiding the first and second sets of strands onto the mandrel comprises the steps of rotating the first set of strands in a first direction about the axis and rotating the second set of strands in a second direction about the axis.

6. The method of claim 1, wherein each strand extends from a spool to the mandrel, and wherein the step of braiding the first and second sets of strands onto the mandrel comprises the steps of rotating the spools of the first set of strands in a first direction about the axis, rotating the spools of the second set of strands in a second direction about the axis, and translating the spools of the first set of strands and the spools of the second set of strands radially with respect to the axis.

7. The method of claim 1 further comprising changing a speed of the braiding of the first and second sets of strands or changing a speed of the movement of the mandrel along the axis as the first and second sets of strands are being braided onto the mandrel to vary a pic count of a resulting braid pattern.

8. The method of claim 1 further comprising applying a first braid pattern to a first portion of the tubular structure and applying a second braid pattern to a second portion of the tubular structure, wherein the first braid pattern is different from the second braid pattern.

9. The method of claim 8, wherein at least one of the first and second braid patterns is a wave pattern.

10. The method of claim 1 further comprising stabilizing a braid pattern of the tubular structure by heat setting the braid pattern.

11. The method of claim 1 further comprising applying a covering to an exterior surface of at least a portion of the tubular structure.

12. The method of claim 1 further comprising stabilizing a braid pattern of the tubular structure by braiding the first and second sets of strands onto at least one polymer layer.

13. The method of claim 12 further comprising applying a covering to an exterior surface of at least a portion of the tubular structure.

14. The method of claim 1, wherein the step of rotating the mandrel comprises angularly oscillating the mandrel.

15. The method of claim 14 further comprising changing a speed of the angular oscillation.

16. The method of claim 1 further comprising varying a maximum angle through which the mandrel rotates.

17. The method of claim 16, wherein varying the maximum angle comprises rotating the mandrel to a first maximum angle in a first direction and rotating the mandrel to a second maximum angle in a second direction, a magnitude of the second maximum angle being different from a magnitude of the first maximum angle.

18. The method of claim 1, wherein the step of braiding the first and second sets of strands comprises braiding the first and second sets of strands onto the mandrel in multiple layers.

19. A tubular structure comprising at least one layer of braided strands, wherein at least a portion of the braided strands exhibits a wave pattern that includes crests and troughs along a length of the tubular structure.

20. The tubular structure of claim 19, wherein the wave pattern includes at least one type of wave selected from the group consisting of a sinusoidal wave, a square wave, and a sawtooth wave.

21. The tubular structure of claim 19, wherein the wave pattern comprises waves having different amplitudes, different frequencies, or different amplitudes and different frequencies.

22. The tubular structure of claim 19 further comprising at least one polymer layer.

23. The tubular structure of claim 19 further comprising a covering applied to a surface of the braided strands.

24. The tubular structure of claim 19, wherein the braided strands exhibit a first wave pattern in one portion of the tubular structure and a second wave pattern in another portion of the tubular structure, wherein the first wave pattern is different from the second wave pattern.

25. The tubular structure of claim 19, wherein the tubular structure includes multiple layers of braided strands.

26. The tubular structure of claim 19, wherein at least some of the strands comprise at least one material selected from the group consisting of metal, polymer, and natural material.

27. The tubular structure of claim 19, wherein at least some of the strands comprise at least one metal selected from the group consisting of steel, stainless steel, shape memory alloy, and elastic alloy.

28. The tubular structure of claim 19, wherein at least some of the strands comprise a shape memory alloy such that a resulting tubular structure is configured to have an expanded configuration when the tubular structure is not constrained and to have a collapsed configuration when the tubular structure is constrained, and wherein the tubular structure is configured to self-expand from the collapsed configuration to the expanded configuration when a constraint is removed.

29. The tubular structure of claim 19, wherein at least some of the strands comprise Nickel Titanium (NiTi) alloy.

30. A medical device configured to treat a target site within a patient'"'"'s body, the medical device comprising a tubular structure, wherein the tubular structure comprises a plurality of braided strands exhibiting a wave pattern that includes crests and troughs along a length of the tubular structure.

31. The medical device of claim 30, wherein the tubular structure comprises a covering applied to a surface of the braided strands.

32. The medical device of claim 30, wherein the braided strands of the tubular structure exhibit a first wave pattern in one portion of the tubular structure and a second wave pattern in another portion of the tubular structure, wherein the first wave pattern is different from the second wave pattern.

33. The medical device of claim 30, wherein the tubular structure includes multiple layers of braided strands.

34. The medical device of claim 30, wherein at least some of the strands of the tubular structure comprise at least one metal selected from the group consisting of steel, stainless steel, shape memory alloy, and elastic alloy.

35. The medical device of claim 30, wherein at least some of the strands of the tubular structure comprise a shape memory alloy such that at least a portion of the medical device is configured to have an expanded configuration when the device is not constrained and to have a collapsed configuration when the device is constrained, and wherein the medical device is configured to self-expand from the collapsed configuration to the expanded configuration when a constraint is removed.