Bifurcated intraluminal prostheses construction and methods

• US 20030195614A1
• Filed: 04/28/2003
• Published: 10/16/2003
• Est. Priority Date: 12/01/1995
• Status: Active Grant

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Evans, Michael A., Lenker, Jay A., Will, Allan R., Ryan, Timothy J., Kim, Steven W., Freislinger, Kirsten
• Granted Patent: US 6,843,803 B2
• Time in Patent Office: Days
• US Class Current: 623/1.16
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• 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 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/30199 Three-dimensional shapes
• CPC Class Codes: A61F 2002/30617 Visible markings for adjusting, locating or measuring
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2230/001 Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0063 Three-dimensional shapes
• CPC Class Codes: A61F 2250/0097 Visible markings, e.g. indicia

Abstract

The present invention provides modular bifurcated intraluminal tubular prostheses, particularly stents and stent-grafts, for the treatment of disease conditions, particularly aneurysms. Modular sections of the prostheses, or “prosthetic modules,” may be selectively assembled to form a prosthesis having characteristics which are tailored to the specific requirements of the patient, including branch angle and branch lumen sizes which match the patients vascular geometry. A Y-connector prosthetic module structure provides support and separation for each of the adjacent branching lumens. Radiopaque markers on the prostheses promote alignment between prosthetic modules and with the body lumen system.

Claims

1. A branching endoluminal stent-graft comprising:

a flexible liner having a main body with a common lumen, a first branch having a first branch lumen, and a second branch having a second branch lumen, the first and second branch lumens being in communication with the common lumen; and

a radially expandable frame disposed over at least a portion of the liner, the frame defining a frame lumen cross-section having a first lobe supporting the first branch, a second lobe supporting the second branch, and at least one isthmus therebetween.

2. A stent-graft as claimed in claim 1, wherein the isthmus is defined by two roughly opposed indentations between the first and second lobes.

3. A stent-graft as claimed in claim 2, further comprising an attachment mechanism which attaches the first lobe and a portion of each indention to the first branch.

4. A stent-graft as claimed in claim 3, wherein the attachment mechanism also attaches the second lobe and an alternate portion of each indentation to the second branch.

5. A stent-graft as claimed in claim 3, wherein the attachment mechanism comprises stitching.

6. A stent-graft as claimed in claim 1, wherein the frame comprises an axially continuous perforate tubular structure extending over at least a portion of both the main body and the first and second branches.

7. A stent-graft as claimed in claim 6, wherein the tubular structure comprises a malleable material.

8. A stent-graft as claimed in claim 1, wherein the frame comprises a plurality of independent frame rings.

9. A stent-graft as claimed in claim 8, wherein a plurality of the frame rings comprise a resilient material.

10. A branching endoluminal stent-graft comprising:

a radially expandable tubular frame; and

a flexible, inelastic liner supported by the frame, the liner having a main body with a common lumen, a first branch having a first branch lumen, and a second branch having a second branch lumen, the first and second branches extending from the main body, the first and second branch lumens being in communication with the common lumen, and a perimeter of the common lumen being smaller than a sum of a perimeter of the first branch lumen and a perimeter of the second branch lumen.

11. A branching stent-graft as claimed in claim 10, wherein the sum of the first and second branch lumen perimeters is in the range between 1 and 20% more than the common lumen perimeter.

12. A branching stent-graft as claimed in claim 10, wherein the frame comprises a resilient structure.

13. A branching stent-graft as claimed in claim 10, wherein the liner comprises a continuously woven textile tube.

14. A branching stent-graft as claimed in claim 13, wherein at least a portion of the liner which defines the common lumen perimeter has been selectively shrunk relative to one of the first and second branch lumen perimeters.

15. A branching stent-graft as claimed in claim 14, wherein the liner comprises a polyester.

16. A branching stent-graft as claimed in claim 10, wherein at least a portion of the liner which defines the first and second branch lumen perimeters has been selectively plastically expanded.

17. A branching stent-graft as claimed in claim 16, wherein the liner has been expanded in situ to match a branching body lumen.

18. An angled branch endoluminal prosthesis comprising:

a radially expandable tubular body main body having a common lumen;

a radially expandable tubular first branch extending from the main body, the first branch having a first branch lumen in fluid communication with the common lumen when the prosthesis is expanded; and

a radially expandable tubular second branch extending from the main body, the second branch having a second branch lumen in fluid communication with the common lumen when the prosthesis is expanded;

wherein the common lumen and the first branch lumen define a first open flow path having a preset first branch angle in the range between 15° and

90°

when the prosthesis is expanded.

19. An angled branch prosthesis as claimed in claim 18, wherein the common lumen and the second branch lumen define second open flow path having a preset second branch angle in the range between 15°

and 90°

when the prosthesis is expanded.

20. An angled branch prosthesis as claimed in claim 19, wherein the first and second branch angles are in the range between 30°

and 45°

.

21. An angled branch prosthesis as claimed in claim 18, wherein at least one of the main body, the first branch and the second branch comprises an expandable perforate frame supporting a flexible liner, and wherein the frame comprises a resilient material and the first flow path defines the first branch angle when the prosthesis is at rest.

22. An angled branch prosthesis as claimed in claim 21, wherein the liner comprises a corrugated region.

23. An angled prosthetic module comprising:

a radially expandable tubular body portion having a bend and a lumen, the lumen providing an open flow path when the bend defines a preset angle in the range between 15 and 90; and

a standard interface disposed on an end of the body portion, the standard interface fittingly engagable with any of a plurality of standard interface ends of other endoluminal prosthetic modules having differing prosthetic characteristics.

24. An angled prosthetic module as claimed in claim 23, wherein the lumen provides the open flow path when the angle is in the range between 30°

and 45°

.

25. An angled prosthetic module as claimed in claim 23, wherein the bend has a preset radial orientation, and further comprising a rotational marker disposed on at least one of the body and the interface end.

26. An angled prosthetic module as claimed in claim 23, wherein the body comprises an expandable perforate frame supporting a flexible liner, wherein the frame comprises a resilient material, and wherein the open flow path defines the angle when the prosthesis is at rest.

27. An angled prosthetic module as claimed in claim 23, wherein the body comprises an expandable perforate frame supporting a flexible liner, and wherein the liner comprises a corrugated region.

28. An endoluminal prosthesis system comprising:

an expandable tubular Y-connector module having a common lumen, a first branch lumen, and a second branch lumen, the first and second branch lumens being in communication with the common lumen; and

a plurality of radially expandable prosthetic modules, each module having a tubular body portion and an end which fittingly engages at least one of the common lumen, the first branch lumen, and the second branch lumen;

wherein the plurality of body portions provide different selectable assembled endoluminal prosthetic characteristics.

29. A prosthesis system as claimed in claim 28, wherein the plurality of body portions differ in at least one prosthetic characteristic selected from the group consisting of length, cross-section, taper, bend angle, axial flexibility, exterior fiber protrusion, liner permeability, liner extensibility, radial conformability, and resilient radial spring force.

30. A prosthesis system as claimed in claim 29, wherein at least two of the plurality of body portions differ in cross-section.

31. A prosthesis system as claimed in claim 28, wherein the plurality of the prosthetic modules have ends which are alternatively fittingly engagable with a branch lumen interface end of the Y-connector module, and wherein at least two of the plurality of alternative prosthetic modules have body portions which provide different preset branch angles from the common lumen, the branch angles in the range between 15°

and 90°

.

32. A prosthesis system as claimed in claim 31, wherein the preset bend angles have a preset radial orientation, and wherein each of the at least two alternative prosthetic modules include rotational markers visible under imaging to indicate the preset radial orientation.

33. A prosthesis system as claimed in claim 28, wherein engagement of the end of each prosthetic module with the Y-connector module affixes the prosthetic module and the Y-connector module with an axial overlap, the overlap being within a predetermined range.

34. A prosthesis kit as claimed in claim 33, wherein at least one of the Y-connector module and each prosthetic module comprise markers visible under imaging to indicate the predetermined range of overlap.

35. An endoluminal prosthetic Y-connector module comprising:

a radially expandable body portion having a common lumen, a first branch lumen, and a second branch lumen, the first and second branch lumens being in communication with the common lumen; and

at least one standard interface end disposed on the body portion adjacent to at least one of the common lumen, the first branch lumen, and the second branch lumen, each standard interface end being fittingly engagable with any of an associated plurality of standard interface ends of other endoluminal prosthetic modules having differing prosthetic characteristics.

36. A Y-connector module as claimed in claim 35, wherein the at least one standard interface comprises both a first branch lumen standard interface and a common lumen branch interface which is different than the first branch interface.

37. A Y-connector module as claimed in claim 36, further comprising a second branch interface disposed at another of the common lumen, the first branch lumen, and the second branch lumen.

38. A Y-connector module as claimed in claim 35, further comprising markers visible under imaging on at least one of the body portion and a marked interface end.

39. A Y-connector module as claimed in claim 38, wherein the markings comprise a flexible radiopaque material disposed on the liner.

40. A Y-connector module as claimed in claim 38, wherein the markers comprise an overlap indicator to facilitate overlapping prosthetic modules within a predetermined range.

41. A Y-connector module as claimed in claim 38, wherein the markers comprise a rotational indicator.

42. A Y-connector module as claimed in claim 41, wherein the rotational indicator comprises alignable elements at differing radial positions and an asymmetric element.

43. A position-indicating stent-graft comprising:

a radially expandable tubular frame;

a flexible liner supported by the frame;

an attachment mechanism which holds the liner on the frame; and

markers disposed on at least one of the frame, the liner, and the attachment mechanism,-the markers visible under imaging to indicate at least one of axial and rotational position of the stent-graft.

44. A position-indicating stent-graft as claimed in claim 43, wherein the markers indicate position under imaging while in a compressed mode and while in an expanded mode.

45. A position-indicating stent-graft as claimed in claim 43, wherein the liner comprises a textile and the markers comprise flexible radiopaque material bonded to the textile.

46. A position-indicating stent-graft as claimed in claim 45, wherein the textile comprises polyester and the radiopaque material comprises tantalum and polyester bonded using a polyester solvent.

47. A position-indicating stent-graft as claimed in claim 43, wherein the markers comprise an overlap indicator to facilitate overlapping prosthetic modules within a predetermined range.

48. A position-indicating stent-graft as claimed in claim 43, wherein the markers comprise a rotational indicator.

49. A position-indicating stent-graft as claimed in claim 48, wherein the rotational indicator comprises alignable elements at differing radial positions about the stent-graft and an asymmetric element.

50. A stent-graft placement method comprising:

inserting a branching stent-graft into a patient body and positioning the branching stent-graft at a target location within a body lumen;

expanding the branching stent-graft at the target location, the branching stent-graft comprising a tubular frame and a flexible liner;

supporting the liner with the frame at a first cross-section so that the frame holds a common lumen open;

supporting the liner with the frame at a second cross-section so that a first lobe of the frame holds a first lumen of the liner open, and a second lobe of the frame holds a second lumen of the liner open; and

separating the first lumen from the second lumen with an isthmus of the frame disposed between the first lobe and the second lobe.

51. A method as claimed in claim 50, wherein the supporting step at the second cross-section comprises supporting the first lumen with adjacent portions of first and second indentations and supporting the second lumen with adjacent portions of the first and second indentations, the first and second indentations defining the isthmus of the frame.

52. A method as claimed in claim 50, wherein the expanding step comprises releasing the frame to expand resiliently at the target location.

53. A method as claimed in claim 52, wherein the expanding step comprises plastically expanding at least a portion of the stent-graft at the target location.

54. A method as claimed in claim 50, further comprising inserting an end of a tubular branch prosthesis into one of the first and second-lumen and expanding the end of the branch prosthesis.

55. A branching endoluminal stent-graft placement method comprising;

inserting a branching stent-graft into a patient body and positioning the branching stent-graft at a target location within a body lumen;

expanding the branching stent-graft at the target location, the branching stent-graft comprising a tubular frame and an inelastic liner; and

holding the liner in an open configuration with the frame so that a perimeter of a common lumen of the liner is smaller than a sum of a perimeter of a first branch lumen of the liner and a perimeter of a second branch lumen of the liner.

56. A method as claimed in claim 55, wherein the expanding step comprises releasing the frame to expand resiliently at the target location.

57. A method as claimed in claim 55, wherein the expanding step comprises plastically expanding at least a portion of the stent-graft at the target location to match a branching body lumen.

58. A method for treating a bent target region of a body lumen comprising:

inserting an endoluminal prosthesis into the body lumen in a radially compressed configuration, the prosthesis having a bend defining a preset angle when in an expanded configuration;

positioning the prosthesis at the bent target region;

rotationally aligning the preset angle of the prosthesis with the bent target region; and

expanding the aligned prosthesis at the bent target region.

59. A method as claimed in claim 58, wherein the expanding step comprises releasing the frame to expand resiliently at the bent target region.

60. A method as claimed in claim 58, wherein the rotationally aligning step comprises imaging rotational markers on the prosthesis.

61. A method as claimed in claim 58, wherein the positioning step comprises placing an end of the prosthesis within an end of a previously positioned prosthesis, and wherein the expanding step comprises immovably engaging the previously positioned prosthesis with the prosthesis end.

62. A method as claimed in claim 58, wherein the positioning step comprises placing a main body portion of the prosthesis within the abdominal aorta, the bend directing a branch portion of the prosthesis along one of the iliac arteries, and the preset angle being in the range between 15°

and 90°

.

63. A method for producing a branching stent-graft comprising:

producing a flexible tubular liner having a main body, a first branch extending from the main body and a second branch extending from the main body;

selectively shrinking at least a portion of the main body relative to at least one of the first branch and the second branch;

attaching a radially compressible frame to the tubular liner.

64. A method as claimed in claim 63, wherein a perimeter of the main body portion is shrunk by up to 20% relative to a perimeter of the at least one of the first branch and the second branch.

65. A method for producing a branching endoluminal prosthesis, the method comprising:

fabricating a resilient tubular frame;

expanding-the frame to an expanded configuration;

heat-treating the expanded frame while restraining the expanded frame so that a cross-section of the frame defines two lobes separated by at least one indentation;

attaching a flexible liner to a first lobe and an adjacent portion of the at least one indentation so that a first lumen of the liner is held open by the frame.

66. A modular endoluminal prosthesis placement method comprising:

inserting a Y-connector prosthetic module within a body lumen system;

positioning a main body of the Y-connector prosthetic module at a target location of a body lumen, the target location adjacent to first and second branch lumens of the body lumen system;

radially expanding the first prosthetic module at the target location;

selecting a preferred first branch prosthetic module from a plurality of alternative branch prosthetic modules having differing prosthetic characteristics; and

positioning an end of the preferred first branch prosthetic module within the first branch of the body lumen system and radially expanding the preferred first branch prosthetic module, the expanded preferred first branch prosthetic module engaging the Y-connector prosthetic module.

67. A method for assembling endoluminal prosthetic modules within a body lumen, the method comprising:

deploying a first tubular prosthetic module within the body lumen;

inserting a second tubular prosthetic module into the body lumen in a radially compressed configuration;

aligning an image of markings disposed on at least one of the first prosthetic module and the second prosthetic module with an image of the other of the first prosthetic module and the second prosthetic module; and

expanding an end of the aligned second prosthetic module to engage an end of the first prosthetic module.

68. A method as claimed in claim 67, wherein the aligning step comprises overlapping the ends of the first and second prosthetic modules within a predetermined range as indicated by an overlap marker band.

69. A method as claimed in claim 67, wherein the aligning step comprises orienting an asymmetric marker element in a generally direction and bringing together the image of alignable marker elements, the marker elements disposed at different radial positions about the second prosthetic module.

70. A method for positioning endoluminal prosthetic modules within a body lumen, the method comprising:

inserting a tubular prosthesis into the body lumen in a radially compressed configuration;

imaging markings disposed on the inserted prosthetic module;

rotationally orienting an asymmetric marker element and bringing together the image of marker disposed at different-radial locations about the prosthesis to align the prosthesis; and

expanding the aligned prosthesis within the body lumen.