Stent/stent graft for reinforcement of vascular abnormalities and associated method

• US 8,747,453 B2
• Filed: 02/18/2008
• Issued: 06/10/2014
• Est. Priority Date: 02/18/2008
• Status: Expired due to Fees

• Current Assignee: St. Jude Medical Cardiology Division Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: AGA Medical Corporation (Abbott Laboratories Incorporated)
• Inventors: Amplatz, Kurt, Oslund, John C., Russo, Patrick, Gu, Xiaoping
• Primary Examiner(s): Sweet, Thomas J
• Assistant Examiner(s): Mathew, Seema
• Application Number:
  US12/032,944
• Publication Number:
  US 20090210048A1
• Time in Patent Office: 2,304 Days
• Field of Search: 623/1.13, 623 118- 119, 623/1.2, 623/1.25, 623/1.3
• US Class Current: 623/1.19
• CPC Class Codes: A61F 2/07 Stent-grafts
• 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 2250/0039 differing in diameter
• CPC Class Codes: A61F 2250/0063 Nested prosthetic parts
• CPC Class Codes: D04C 1/02 made from particular materials
• CPC Class Codes: D04C 3/48 Auxiliary devices
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents

Abstract

A stent/stent graft for reinforcement of vascular abnormalities and an associated method are provided. According to on embodiment, the stent/stent graft includes a flexible tubular structure comprising proximal and distal ends and having a heat set configuration. The tubular structure is configured to engage a lumen upstream and downstream of a vascular abnormality, such as an aneurysm, and a portion between the proximal and distal ends of the tubular structure is configured to engage the aneurysm.

Claims

1. A stent/stent graft for treating a vascular abnormality in a lumen, the stent/stent graft comprising:

a flexible tubular structure comprising a proximal end and a distal end, the flexible tubular structure having a heat set configuration and an expanded configuration, the heat set configuration having a heat set diameter and the expanded configuration having a maximum expandable diameter of the flexible tubular structure, wherein the flexible tubular structure is heat set in the heat set configuration such that the heat set diameter between the proximal and distal ends of the flexible tubular structure is larger than a diameter of at least one of the proximal or distal ends of the flexible tubular structure and is smaller than a maximum diameter of the vascular abnormality, and wherein the flexible tubular structure is configured to expand from the heat set diameter to the maximum expandable diameter in response to a distally directed axial compressive force such that the flexible tubular structure is configured to conform to the maximum diameter of the vascular abnormality.

2. The stent/stent graft of claim 1, wherein the flexible tubular structure is configured to be constrained from the heat set configuration to a smaller configuration than the heat set configuration and return to the heat set configuration when unconstrained.

3. The stent/stent graft of claim 1, wherein the flexible tubular structure comprises a plurality of layers, each of the plurality of layers comprising a plurality of braided strands.

4. The stent/stent graft of claim 3, wherein the plurality of layers comprise respective flexible tubular structures coaxially disposed in an overlying relationship.

5. The stent/stent graft of claim 3, wherein each of the plurality of layers comprises a plurality of braided strands of an elastic metallic alloy.

6. The stent/stent graft of claim 1, wherein the flexible tubular structure is configured to engage the lumen upstream and downstream of an aneurysm, and wherein a portion between the proximal and distal ends of the flexible tubular structure is configured to expand to about the maximum diameter of the aneurysm in response to the distally directed axial compressive force.

18. A method for treating a vascular abnormality in a lumen, the method comprising:

delivering a stent/stent graft according to claim 1 proximate to the vascular abnormality in the lumen; and

axially compressing the stent/stent graft in a distal direction such that the flexible tubular structure expands from the maximum heat set diameter to the maximum expandable diameter to conform to the maximum diameter of the vascular abnormality.

19. The method of claim 18, further comprising constraining the stent/stent graft to a smaller diameter than the heat set configuration.

20. The method of claim 19, wherein constraining comprises radially compressing the stent/stent graft to a diameter of less than about 15 French.

21. The method of claim 18, further comprising deploying the stent/stent graft within the lumen such that the stent/stent graft engages the lumen upstream and downstream of a vascular abnormality, and wherein axially compressing comprises axially compressing the stent/stent graft such that a portion between the proximal and distal ends of the stent/stent graft engages the vascular abnormality.

33. The stent/stent graft of claim 1, wherein the flexible tubular structure comprises at least one layer of braided strands.

34. The stent/stent graft of claim 33, wherein the at least one layer of braided strands comprises an elastic metallic alloy.

35. The stent/stent graft of claim 1, wherein the flexible tubular structure is heat set in the expanded configuration.

36. The stent/stent graft of claim 33, wherein the flexible tubular structure is braided between its proximal and distal ends at a predetermined helix angle, and wherein the maximum expandable diameter is limited by the helix angle.

38. The stent/stent graft of claim 1, wherein a ratio of the maximum expandable diameter to the maximum heat set diameter is about 1.4 to 1.5.

7. A stent/stent graft for treating a vascular abnormality within a lumen, the stent/stent graft comprising:

a flexible tubular structure comprising a proximal end and a distal end, the proximal and distal ends of the flexible tubular structure sized and configured to engage the lumen upstream and downstream of the vascular abnormality, the flexible tubular structure having a first heat set configuration and a second heat set configuration, the first heat set configuration having a first maximum heat set diameter and the second heat set configuration having a second maximum heat set diameter, wherein the first heat set configuration comprises different diameters along its length such that a portion between the proximal and distal ends of the flexible tubular structure corresponds to the first maximum heat set diameter and has a larger diameter than at least one of the proximal or distal ends of the flexible tubular structure, wherein the first maximum heat set diameter is less than both a maximum diameter of the vascular abnormality and the second maximum heat set diameter, and wherein the portion of the flexible tubular structure is configured to expand from the first maximum heat seat diameter to the second maximum heat set diameter to at least partially conform to the maximum diameter of the vascular abnormality.

8. The stent/stent graft of claim 7, wherein the flexible tubular structure is configured to be constrained to a diameter of less than about 15 French for delivery within a catheter.

9. The stent/stent graft of claim 7, wherein the flexible tubular structure is configured to be constrained to a diameter of less than about 12 French for delivery within a catheter.

10. The stent/stent graft of claim 7, wherein the flexible tubular structure is configured to be constrained to a diameter of less than about 10 French for delivery within a catheter.

11. The stent/stent graft of claim 7, wherein the flexible tubular structure is configured to be constrained to a diameter of less than about 8 French for delivery within a catheter.

12. The stent/stent graft of claim 7, wherein the portion between the proximal and distal ends of the flexible tubular structure is configured to expand from the first maximum heat set diameter to the second maximum heat set diameter in response to a distally directed axial compressive force.

13. The stent/stent graft of claim 7, wherein the flexible tubular structure is configured to be constrained to a smaller configuration than the first heat set configuration and return to the first heat set configuration when unconstrained.

14. The stent/stent graft of claim 13, wherein the flexible tubular structure has a reduced diameter when constrained to the smaller configuration from the first maximum heat set diameter, and wherein a ratio of the first maximum heat set diameter to the reduced diameter is within the range of about 3:

1 to 7;

1.

15. The stent/stent graft of claim 13, wherein the portion between the proximal and distal ends of the flexible tubular structure is configured to self-expand when unconstrained.

16. The stent/stent graft of claim 7, wherein the portion between the proximal and distal ends of the flexible tubular structure is bulbous.

17. The stent/stent graft of claim 7, wherein the portion between the proximal and distal ends of the flexible tubular structure is configured to substantially conform to a contour of the vascular abnormality along the entire length of the vascular abnormality.

22. A method for treating a vascular abnormality in a lumen, the method comprising:

delivering a stent/stent graft according to claim 7 proximate to the vascular abnormality in a lumen; and

deploying the stent/stent graft such that the proximal and distal ends of the the flexible tubular structure engage the lumen upstream and downstream of the vascular abnormality and the portion between the proximal and distal ends of the the flexible tubular structure at least partially conforms to a contour of the vascular abnormality.

23. The method of claim 22, wherein deploying comprises deploying the stent/stent graft such that the proximal and distal ends of the flexible tubular structure expand to about a diameter of the lumen upstream and downstream of the vascular abnormality, and the portion between the proximal and distal ends of the graft flexible tubular structure expands to about the maximum diameter of the vascular abnormality.

24. The method of claim 23, further comprising axially compressing the stent/stent graft in a distal direction such that the first maximum heat set diameter of the graft the flexible tubular structure further expands to the second maximum heat set diameter of the flexible tubular structure.

25. The method of claim 23, further comprising constraining the stent/stent graft to a smaller configuration than the first heat set configuration.

37. The stent/stent graft of claim 7, wherein the flexible tubular structure comprises strands braided between its proximal and distal ends at a predetermined helix angle, and wherein the maximum expandable diameter is limited by the helix angle.

26. A stent/stent graft for treating an aneurysm within a lumen, the stent/stent graft comprising:

a flexible tubular structure comprising a proximal end and a distal end configured to engage the lumen upstream and downstream of the aneurysm, wherein the flexible tubular structure is heat set to include different diameters along its length in a relaxed state such that a portion between the proximal and distal ends of the flexible tubular structure has a larger diameter than at least one end of the tubular structure, wherein the maximum heat set diameter of the flexible tubular structure is less than a maximum diameter of the aneurysm, and wherein the flexible tubular structure is configured to conform to a contour of the aneurysm along the entire length of the aneurysm in response to a distally directed axial compressive force to promote endothelialization and re-enforcement of the aneurysm.

27. A stent/stent graft for treating an aneurysm within a lumen, the stent/stent graft comprising:

a flexible tubular structure comprising a proximal end and a distal end configured to engage the lumen upstream and downstream of the aneurysm, wherein the flexible tubular structure is heat set to include different diameters along its length in a relaxed state such that a portion between the proximal and distal ends of the flexible tubular structure has a larger diameter than at least one end of the flexible tubular structure, wherein a maximum heat set diameter of the flexible tubular structure is less than a maximum diameter of the aneurysm, and wherein the flexible tubular structure is configured to conform to a contour of the aneurysm along the entire length of the aneurysm in response to a distally directed axial compressive force and to occlude blood flow therethrough.

28. The stent/stent graft of claim 27, wherein the portion between the proximal and distal ends of the flexible tubular structure is configured to be at least partially endothelialized.

29. The stent/stent graft of claim 27, wherein the portion between the proximal and distal ends of the flexible tubular structure is configured to be substantially endothelialized.

30. A stent/stent graft for treating a vascular aneurysm comprising:

a tubular structure comprising elastic braided metal strands and having a proximal end and a distal end, wherein the tubular structure is heat set to include different diameters along its length in a relaxed state such that a portion of the tubular structure between the proximal and distal ends has a larger diameter than at least one end of the tubular structure, wherein the maximum heat set diameter is less than a maximum diameter of the aneurysm, and wherein the tubular structure is configured to be placed within the aneurysm such that the maximum heat set diameter conforms to the maximum diameter of the aneurysm in response to a distally directed axial compressive force.

31. The stent/stent graft of claim 30, wherein the tubular structure comprises one or more polymer strands.

32. The stent/stent graft of claim 30, wherein the tubular structure comprises a plurality of layers, wherein at least one layer comprises elastic braided metal strands and at least one other layer comprises braided polymer strands.