STENT WITH SEGMENTED GRAFT

• US 20110093055A1
• Filed: 12/21/2010
• Published: 04/21/2011
• Est. Priority Date: 05/22/2002
• Status: Active Grant

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Kujawski, Dennis
• Granted Patent: US 8,197,533 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• 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 2002/061 provided with means for allowing access to secondary lumens
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2250/0007 for adjusting length
• CPC Class Codes: A61F 2250/0064 Sets comprising a plurality of prosthetic parts of different sizes

Abstract

A stent-graft comprising an expandable stent and a plurality of graft segments, each graft segment having a first end attached to the stent and a second end not attached to the stent. In one embodiment, the plurality of overlapped graft segments form a continuous conduit wherein each overlap between axially adjacent graft segments comprises a fluid-tight seal when the stent in the radially expanded configuration sandwiches the graft segments against a wall of a body lumen. In another embodiment, there are one or more discontinuities in the plurality of graft segments. The discontinuities may be aligned with branch lumens. The graft segments may be cut perpendicular to the stent-graft axis, or on a bias. A delivery system for and method of deploying the stent-graft are also claimed.

Claims

1. A stent-graft comprising:

a single expandable stent of a particular length; and

a plurality of discrete and separate grafts each lining a different portion of the expandable stent, as determined by being longitudinally displaced along the particular length, each graft having a first end attached to the stent and a second end not attached to the stent.

2. The stent-graft of claim 1, wherein the grafts radially overlie the stent.

3. The stent-graft of claim 2, wherein at least two axially adjacent grafts overlap one another to form an overlap.

4. The stent-graft of claim 3, wherein the plurality of grafts and at least one overlap therebetween form a continuous conduit.

5. The stent-graft of claim 3, wherein the stent has a radially expanded configuration and a radially compressed configuration and each overlap comprises a fluid-tight seal with the stent in the radially expanded configuration sandwiching the graft segments against a wall of a body lumen.

6. The stent-graft of claim 1, wherein the stent comprises a self-expanding material.

8. The stent-graft of claim 1, wherein the stent comprises a balloon-expandable material.

9. The stent-graft of claim 8, wherein the balloon-expandable material comprises stainless steel.

10. The stent-graft of claim 1, wherein the graft comprises a material selected from the group consisting of:

polyethyleneterepthalate (PET), polyetheretherketone (PEEK), polysulfone, polytetrafluroethylene (PTFE), expanded polytetrafluroethylene (ePTFE), fluorinated ethylene propylene (FEP), polycarbonate urethane, a polyolefin, silicone, and polyurethane.

11. The stent graft of claim 10, wherein the graft comprises a polyolefin selected from the group consisting of:

polypropylene, polyethylene, or high density polyethylene (HDPE).

12. The stent-graft of claim 1, wherein the stent-graft is adapted for treatment of a thoracic aortic aneurysm.

13. The stent-graft of claim 1, wherein all of the plurality of graft segments are of equal length.

14. The stent-graft of claim 1, wherein one or more grafts are positioned upstream of one or more longitudinally displaced grafts.

15. The stent-graft of claim 2, further comprising at least a portion of the stent not radially overlaid by any of the plurality of grafts.

16. The stent-graft of claim 15, wherein the portion of the stent that is not radially overlaid by a graft is an end of the stent adapted to be positioned upstream relative to the rest of the stent-graft in a body lumen having fluid flowing downstream from an upstream location.

17. The stent-graft of claim 3, wherein the overlap extends along an entire periphery of the stent-graft.

18. The stent-graft of claim 3, wherein the overlap extends along less than an entire periphery of the stent-graft.

19. The stent-graft of claim 1, wherein the stent-graft has a central axis and each graft has opposite ends that are perpendicular to the central axis.

20. The stent-graft of claim 1, comprising at least one gap between axially adjacent grafts, creating a discontinuity in the plurality of grafts.

21. The stent-graft of claim 1, wherein the plurality of grafts has at least one discontinuity therein.

22. The stent-graft of claim 21, wherein the stent-graft is adapted for deployment in a body lumen having at least one branch, wherein the discontinuity is positioned to align with the branch.

7. The stent-graft of claim 7, wherein the self-expanding material comprises nitinol.

23. A stent-graft adapted for deployment inside a body lumen in a distal deployment location from a proximal access location outside the body lumen, the stent-graft comprising:

a single expandable stent of a particular length underlying a plurality of discrete and separate graft segments, as determined by being longitudinally displaced along the particular length, each of the graft segments having a distal upstream end attached to the stent and a proximal downstream end not attached to the stent;

a plurality of links at or near the distal upstream end of each graft segment for linking the stent and the graft segments together; and

a lapped interface between at least one pair of axially adjacent graft segments in which the proximal downstream end of a distal graft segment axially overlaps the distal upstream end of a proximal graft segment.

24. The stent-graft of claim 23, wherein the stent-graft consists essentially of the plurality of graft segments, the expandable stent, the plurality of links, and the lapped interfaces between the graft segments.

25. A stent-graft adapted for deployment inside a body lumen having fluid therein that flows from an upstream direction to a downstream direction, the stent-graft comprising:

a single expandable stent of a particular length;

a plurality of discrete and separate graft segments overlying the stent, as determined by being longitudinally displaced along the particular length, each graft segment having an upstream end and a downstream end and linked to the stent only at or near the upstream end, wherein for each graft segment the downstream end overlaps the upstream end of a first axially adjacent graft segment, the upstream end overlaps the downstream end of a second axially adjacent graft segment, or both.

26. The stent-graft of claim 25, wherein each overlap between axially adjacent graft segments forms a fluid-tight seal when the stent is in a radially-expanded configuration and sandwiches the graft segments against a wall of a body lumen.

27. A stent-graft adapted for deployment inside a body lumen having fluid therein that flows from an upstream direction to a downstream direction, the stent-graft comprising:

a single expandable stent of a particular length;

a first graft segment having an upstream end and a downstream end, the first graft segment attached to the stent only at the first graft segment upstream end; and

a second graft segment discrete and separate from the first graft segment, as determined by being longitudinally displaced along the particular length, having an upstream end and attached to the stent only at the second graft segment upstream end in an axial location that is upstream of the downstream end of the first graft segment, such that the first graft segment downstream end overlaps the first graft segment upstream end and the first graft segment downstream end is not attached to the stent.

28. A delivery system for deploying a stent-graft inside a body lumen having fluid therein that flows from an upstream direction to a downstream direction, the delivery system comprising:

a stent graft having a compressed configuration and an expanded configuration, the stent-graft comprising;

a single expandable stent of a particular length and a plurality of discrete and separate graft segments overlying the stent, as determined by being longitudinally displaced along the particular length, each graft segment having a first upstream end attached to the stent and a second downstream end not attached to the stent; and

an outer sheath overlying the stent-graft in the compressed configuration and retractable in the downstream direction.

29. The delivery system of claim 28 further comprising a shaft mounted coaxially within the outer sheath, and a catheter tip on the upstream end of the shaft.

30. The delivery system of claim 29, wherein the delivery system comprises an inside portion for introduction into the body lumen and an outside portion for remaining outside the body lumen, the inside portion consisting essentially of:

the stent-graft, the outer sheath, the shaft, and the catheter tip.

31. The delivery system of claim 29, wherein the shaft and the catheter tip each have a guidewire lumen therethrough and the delivery system further comprises a guidewire.

32. The delivery system of claim 31, wherein the delivery system comprises an inside portion for introduction into the body lumen and an outside portion for remaining outside the body lumen, the inside portion consisting essentially of:

the stent-graft, the outer sheath, the shaft, the catheter tip, and the guidewire.

33. A method for delivering a stent-graft into a body lumen, the stent-graft having a compressed configuration and an expanded configuration, the body lumen having an intraluminal fluid therein flowing in a downstream direction from an upstream location, the method comprising:

introducing a delivery system into the body lumen, the delivery system comprising the stent-graft in the compressed configuration and an outer sheath overlying the stent graft, the stent-graft comprising;

a single expandable stent of a particular length and a plurality of discrete and separate graft segments overlying the stent, as determined by being longitudinally displaced along the particular length, each graft segment having an upstream end attached to the stent and a downstream end not attached to the stent;

retracting the outer sheath in the downstream direction such that when a first graft segment is completely unsheathed, the intraluminal fluid flows in a first path through the stent and between the downstream end of the first graft segment and the upstream end of the outer sheath until an upstream end of a second graft segment is unsheathed sufficiently to cut off flow through the first path, the intraluminal fluid then flowing through a second path through the stent between the downstream end of the second graft segment and the outer sheath when the second graft segment is completely unsheathed; and

continuing to retract the outer sheath until the stent-graft is fully deployed.

34. The method of claim 33, wherein the delivery system further comprises a shaft mounted coaxially within the outer sheath, and a catheter tip on the upstream end of the shaft, the shaft and the catheter tip both having a guidewire lumen therethrough, the method comprising inserting a guidewire into the body lumen over which the delivery system is introduced.

35. The method of claim 33, further comprising deploying the stent-graft such that the plurality of graft segments overlap one another to create a fluid tight seal at each interface between overlapping graft segments, creating a continuous fluid conduit.

36. The method of claim 33, wherein the stent-graft further comprises one or more discontinuities in the plurality of graft segments and the body lumen comprises one or more branch lumens, the method comprising deploying the stent-graft such that the discontinuities are aligned with the branch lumens.

37. The method of claim 33, comprising deploying the stent-graft to repair a thoracic aortic aneurysm.

38. The method of claim 33, wherein the graft segments have different axial lengths, the method comprising deploying graft segments with relatively shorter axial lengths upstream of graft segments with relatively longer axial lengths.

39. The method of claim 33, wherein the graft segments have different axial lengths, the method comprising deploying graft segments with relatively shorter axial lengths in a curved or tortuous portion of a body lumen.

40. The method of claim 33, further comprising aligning an upstream end of the stent-graft with a first position on the body lumen before retracting the outer sheath, in which retracting and continuing to retract the outer sheath are performed without the stent-graft migrating from the first position.