Braided branching stent, method for treating a lumen therewith, and process for manufacure thereof

• US 20020111674A1
• Filed: 04/03/2002
• Published: 08/15/2002
• Est. Priority Date: 01/31/2000
• Status: Active Grant

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Dennis A. Peiffer, Patrick A. Haverkost, Paul F. Chouinard
• Inventors: Chouinard, Paul F., Haverkost, Patrick A., Peiffer, Dennis A.
• Granted Patent: US 6,942,693 B2
• Time in Patent Office: Days
• US Class Current: 623/1.35
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/821 Ostial stents
• CPC Class Codes: A61F 2230/001 Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: D04C 1/06 Braid or lace serving particular purposes
• CPC Class Codes: D04C 3/14 Spool carriers
• CPC Class Codes: D04C 3/48 Auxiliary devices
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents

Abstract

A bifurcated, braided stent has a body that branches into a plurality of legs and is adapted for deployment in a lumen. At least a portion of each leg of the stent comprises a discrete plurality of continuous filaments braided together, and at least a portion of the body comprises one or more of the continuous filaments from each of the legs braided together. The stent can be used for treating a diseased bifurcated lumen of a human being by deploying the stent therein. The stent can be constructed by a process comprising braiding each plurality of filaments to form the leg sections, and braiding one or more filaments from each plurality of filaments together to form the body. The process may be performed by creating the legs first and then the body, or vice versa. The stent may be constructed on a mandrel using a braiding machine.

Claims

1. A branching stent for deployment in a lumen, the stent comprising a body that branches into a plurality of legs, wherein at least a first leg portion of each leg comprises a discrete plurality of continuous filaments braided together and at least a first body portion of the body comprises at least one of said continuous filaments from each discrete plurality of continuous filaments braided together.

2. The stent of claim 1 wherein at least one of said legs or said body further comprises a second portion thereof having a non-braided stent architecture.

3. The stent of claim 1 wherein each of said legs and said body has a respective length and each of said legs comprises said first leg portion along the entire length of said legs and said body comprises said first body portion along the entire length of said body.

4. The stent of claim 1 wherein said plurality of legs comprises a first leg and a second leg, the first leg portion of the first leg comprises a first discrete plurality of continuous filaments braided together, the first leg portion of the second leg comprises a second discrete plurality of continuous filaments braided together, and the first body portion comprises the first plurality of continuous filaments braided together with the second plurality of continuous filaments.

5. The stent of claim 4 further comprising an interface between the body and the first and second legs, wherein said first and second plurality of continuous filaments define an open crotch region between the first and second legs at the interface.

6. The stent of claim 4 further comprising an interface between the body and the legs, wherein said first and second plurality of continuous filaments define a closed crotch region between the first and second legs at the interface.

7. The stent of claim 6, wherein said first and second plurality of continuous filaments define an open hip region between each leg and the body at the interface.

8. The stent of claim 6 wherein the closed crotch region comprises at least one overlap where a filament in the first plurality of filaments crosses with at least one filament in the second plurality of filaments.

9. The stent of claim 8 wherein the closed crotch region comprises two overlapping filaments from the first plurality of filaments and the second plurality of filaments.

10. The stent of claim 1 wherein at least one set of two or more adjacent filaments is grouped together in at least one location with one of:

a suture or a staple.

11. The stent of claim 10 further comprising an interface between the body and the legs, wherein said plurality of continuous filaments defines a closed crotch region between the legs at the interface, wherein the adjacent filaments grouped together comprise at least one filament from a first plurality of filaments of a first leg grouped together in the crotch region with at least one filament from a second plurality of filaments of a second leg.

12. The stent of claim 1 wherein the body has a first end and each leg has a second end, at least one of the ends comprising an end portion that is flared radially outward.

13. The stent of claim 2 wherein the body has a first end and the legs each have a second end, at least one of the ends comprising an end portion having a non-braided stent architecture.

14. The stent of claim 1 further comprising a biocompatible graft connected thereto as one of:

an outer covering, an inner liner, or a combination thereof.

15. The stent of claim 1 wherein the filaments comprise wire.

16. The stent of claim 15 wherein the wire comprises one of:

nitinol or stainless steel.

17. The stent of claim 1 wherein the filaments comprise at least one tapered filament comprising at least one first region having a first, relatively-larger cross-sectional area and at least one second region having a second, relatively-smaller cross-sectional area.

18. The stent of claim 17 wherein the tapered filament is configured such that the stent body comprises the first region having the first, relatively-larger cross-sectional area and each of the stent legs comprises one of the second regions having the second, relatively-smaller cross-sectional area.

19. The stent of claim 17 wherein the tapered filament is configured such that each of the stent legs comprises the first region having the first, relatively-larger cross-sectional area and the stent body comprises one of the second regions having the second, relatively-smaller cross-sectional area.

20. The stent of claim 1 wherein the stent extends between a body end and a plurality of leg ends and in which the filaments terminate at each of the ends.

21. The stent of claim 1 wherein the stent extends between a body end and a plurality of leg ends and in which each filament forms a continuous apex at one of:

(a) the body end or (b) the plurality of leg ends.

22. The stent of claim 1 wherein the stent extends between a body end and a plurality of leg ends and in which each filament at one of:

(a) the body end, or (b) the plurality of leg ends, terminates in an atraumatic termination structure.

23. The stent of claim 1 wherein the stent comprises a radially compressed configuration for introduction into the lumen and a radially expanded configuration for deployment within the lumen.

24. The stent of claim 23 wherein the stent is expandable between the radially compressed configuration and the radially expanded configuration by one of:

balloon expansion, self-expansion via spring elasticity, or self-expansion via a thermally or stress-induced return of a pre-conditioned memory material.

25. The stent of claim 4 wherein the stent is adapted for deployment within a bifurcated region of an aorta where the aorta branches into first and second iliac arteries, the first leg of the stent adapted to be deployed in the first iliac artery and the second leg of the stent adapted to be deployed in the second iliac artery and the body of the stent adapted to be deployed in the aorta.

26. The stent of claim 1 wherein each leg comprises a 1:

1 single filament braiding ratio.

27. The stent of claim 4 wherein each leg comprises a 1:

1 single filament braiding ratio and the body comprises a 2;

2 single filament braiding ratio.

28. The stent of claim 4 wherein each leg comprises a 1:

1 single filament braiding ratio and the body comprises a 1;

1 paired filament braiding ratio.

29. The stent of claim 1 wherein the stent comprises a unitary stent having at least two legs integrally attached to the body, each leg adapted for at least partial insertion into a branch of said lumen.

30. The stent of claim 1 wherein the stent comprises a modular stent and wherein at least one leg comprises a socket portion for receiving a modular leg element.

31. A method for treating a diseased branched lumen of a human being, the branched lumen comprising a main section that branches into a plurality of branches, the method comprising the step of deploying within the branched lumen a branching stent comprising a body that branches into a plurality of legs, wherein at least a first leg portion of each leg comprises a discrete plurality of continuous filaments braided together and at least a first body portion of the body comprises at least one of said continuous filaments from each discrete plurality of continuous filaments braided together, the deployment step comprising deploying the body in the main section and deploying each leg within one of the branches.

32. The method of claim 31 wherein the plurality of branches comprises a first branch and a second branch, and the plurality of legs comprises a first leg and a second leg, the first leg comprising a first discrete plurality of continuous filaments, the second leg comprising a second discrete plurality of continuous filaments, and the first body portion comprising the first plurality of continuous filaments braided together with the second plurality of continuous filaments, the method comprising deploying the stent within the lumen such that the body is deployed in the main section, the first leg is deployed in the first branch, and the second leg is deployed in the second branch.

33. A process for constructing a braided, branched stent having a body and a plurality of legs, each leg comprising a discrete plurality of filaments, the process comprising the steps of:

a) braiding each plurality of filaments to individually form at least first leg portions of each of the legs; and

b) braiding at least one filament from each plurality of continuous filaments together to form a first body portion of the body.

34. The process of claim 33 wherein each leg and the body have respective lengths and the process further comprises braiding the plurality of filaments in each leg over the entire length of each leg and braiding all of the filaments of each plurality of leg filaments together in the body over the entire length of the body.

35. The process of claim 33 further comprising one of:

configuring at least a fraction of one plurality of leg filaments into a non-braided configuration in a second portion of the leg, configuring at least a fraction of each plurality of leg filaments into a non-braided configuration in a second portion of the body, or a combination thereof.

36. The process of claim 33 wherein the plurality of legs comprises a first leg and a second leg and step (a) comprises the steps of:

i) braiding a first discrete plurality of filaments to form the first leg; and

ii) braiding a second discrete plurality of filaments to form the second leg; and

step (b) comprises braiding the first plurality of filaments and the second plurality of filaments together to form the body.

37. The process of claim 36 wherein step (a) is performed prior to step (b).

38. The process of claim 36 wherein step (b) is performed prior to step (a).

39. The process of claim 36 comprising braiding the stent around a mandrel having a mandrel body, a first detachable mandrel leg, and a second detachable mandrel leg, wherein step (a)(i) comprises braiding the first plurality of filaments about the first detachable mandrel leg, step (a)(ii) comprises braiding the second plurality of filaments about the second detachable mandrel leg, and step (b) comprises braiding the first plurality of filaments and second plurality of filaments together about the mandrel body.

40. The process of claim 36 comprising performing the braiding on a braiding machine having a predetermined plurality of bobbins adapted to revolve in a pattern about a longitudinal axis, a first set of bobbins adapted to revolve in a first circumferential direction and a second set of bobbins adapted to revolve in a second circumferential direction, each bobbin mounted upon a bobbin carrier adapted to carry at least one bobbin, each bobbin adapted to provide one or more filaments for braiding within the stent, step (a) comprising in step (i) using filaments from a first portion of the predetermined plurality of bobbins to braid the first leg about the first detachable mandrel leg positioned substantially along the longitudinal axis in a braiding zone, the braiding zone being a conical zone defined by the filaments extending from the bobbins to the stent on the mandrel, and in step (ii) using filaments from a second portion of the predetermined plurality of bobbins to braid the second leg about the second detachable mandrel leg positioned in the braiding zone;

and step (b) comprising using filaments from both portions of the predetermined plurality of bobbins to braid the body about the mandrel body positioned in the braiding zone.

41. The process of claim 40 further comprising the steps of:

A) first performing step (a)(i);

B) then removing the first portion of the predetermined plurality of bobbins from the braiding machine and removing the first mandrel leg from the braiding zone;

C) then performing step (a)(ii);

D) then returning the first portion of the predetermined plurality of bobbins to the braiding machine, attaching the first mandrel leg and the second mandrel leg to the mandrel body, and positioning the mandrel body in the braiding zone; and

E) then performing step (b).

42. The process of claim 41 wherein prior to removing the first portion of the predetermined plurality of bobbins from the machine, the process further comprises grouping the first portion of the predetermined plurality of bobbins on a first side of the machine;

and prior to returning the first portion of the predetermined plurality of bobbins to the first side of the machine, the process further comprises grouping the second portion of the predetermined plurality of bobbins onto a second side of the machine.

43. The process of claim 42 wherein after or during the step of returning the first portion of the predetermined plurality of bobbins to the machine in step D, the process further comprises the steps of:

D1) identifying at least one adjacent pair of bobbins comprising a first bobbin from the first portion of the predetermined plurality of bobbins and a second bobbin from the second portion of the predetermined plurality of bobbins; and

D2) crossing the filaments attached to the first and second bobbins so that the first leg and the second leg of the stent are interlocked together by the crossed filaments.

44. The process of claim 41 wherein the step of returning the first portion of the predetermined plurality of bobbins to the machine in step D comprises placing each bobbin from the first portion of the predetermined plurality of bobbins in a position located circumferentially between two bobbins from the second portion of the predetermined plurality of bobbins.

45. The process of claim 40 comprising the steps of:

A) first performing step (b);

B) then removing the second portion of the predetermined plurality of bobbins from the machine and attaching the first mandrel leg to the mandrel body;

C) then performing step (a)(i);

D) then returning the second portion of the predetermined plurality of bobbins to the machine and removing the first portion of the predetermined plurality of bobbins from the machine, attaching the second mandrel leg to the mandrel body, detaching the first mandrel leg from the mandrel body, and positioning the first leg of the stent outside the braiding zone so that the first leg does not interfere with performance of step (a)(ii); and

E) then performing step (a)(ii).

46. The process of claim 45 comprising designating the second portion of the predetermined plurality of bobbins to be removed from the machine in step B as all of the bobbins on one side of the machine.

47. The process of claim 46 wherein prior to removing the second portion of the predetermined plurality of bobbins in step B, the process further comprises the steps of:

B1) identifying at least one adjacent pair of bobbins comprising a first bobbin from the first portion of the predetermined plurality of bobbins and a second bobbin from the second portion of the predetermined plurality of bobbins; and

B2) crossing the filaments attached to the first and second bobbins so that the first leg and the second leg of the stent are interlocked together by the crossed filaments.

48. The process of claim 46 comprising designating the first and second portions of the predetermined plurality of bobbins as alternating bobbins of each set of bobbin carriers such that in each set, each bobbin from the first portion is positioned on a bobbin carrier circumferentially between two bobbins from the second portion at a step in the process immediately prior to removal of the second portion from the machine in step B.

49. The process of claim 40 wherein:

the first set of bobbin carriers revolves about a longitudinal axis in a clockwise circumferential direction,

the second set of bobbin carriers revolves about the longitudinal axis in a counterclockwise circumferential direction, and

the braiding process in step (a) comprises braiding each leg in a 1;

1 single filament braiding ratio and configuring each of the first set of bobbin carriers and second set of bobbin carriers with bobbins spaced one bobbin per every other carrier such that each carrier having a bobbin thereon is positioned circumferentially between two empty carriers in that set of bobbin carriers.

50. The process of claim 49 wherein the braiding process in step (b) comprises braiding the body in a 2:

2 single filament braiding ratio and configuring both the first set of bobbin carriers and the second set of bobbin carriers with a single bobbin on every carrier.

51. The process of claim 49 wherein the braiding process in step (b) comprises braiding the body in a 1:

1-paired filament braiding ratio.

52. The process of claim 51 further comprising configuring the first set of bobbin carriers and the second set of bobbin carriers in a 1:

1-in-train configuration.

53. The process of claim 33 comprising braiding the stent using at least one tapered filament comprising at least one first region having a first, relatively-larger cross-sectional area and at least one second region having a second, relatively-smaller cross-sectional area.

54. The process of claim 53 comprising braiding each braided portion of each leg using one of the second regions of the tapered filament and braiding the braided portion of the body using the first region of the tapered filament.

55. The process of claim 53 comprising braiding each braided portion of each leg using one of the first regions of the tapered filament and braiding the braided portion of the body using the second region of the tapered filament.

56. The process of claim 40 comprising prior to steps (a) and (b), winding the filaments between two bobbins such that a first end of the filament is wound on a first bobbin and a second end of the filament is wound on a second bobbin, and positioning a midpoint of the filament on the mandrel to form an apex at an end of the stent.

57. The process of claim 53 comprising prior to steps (a) and (b), winding each tapered filaments between two bobbins such that a first end of the filament is wound on a first bobbin and a second end of the filament is wound on a second bobbin, and positioning a midpoint of the filament on the mandrel to form an apex at an end of the stent.

58. The process of claim 57 wherein the first end is located within one of the second regions having the second, relatively-smaller cross-sectional area and the second end is located within another of the second regions and the midpoint of the filament is located within the first region having the first, relatively-larger cross-sectional area.

59. The process of claim 57 wherein the first end is located within one of the first regions having the first, relatively-larger cross-sectional area and the second end is located within another of the first regions and the midpoint of the filament is located within the second region having the second, relatively-smaller cross-sectional area.

60. The process of claim 33 wherein step (a) is performed on a first braiding machine and step (b) is performed on a second braiding machine.

61. A multi-section stent comprising at least one braided section, which comprises a cylindrical mesh of a first set of filaments, and at least one non-braided, wound end section, which is connected to said braided section and comprises a second set of one or more filaments in a repeating configuration having at least one bent portion, wherein at least one continuous filament is contained in both the first and second sections and forms a continuous apex in the wound end section.