Stent pattern for high stent retention

• US 20070191926A1
• Filed: 02/14/2006
• Published: 08/16/2007
• Est. Priority Date: 02/14/2006
• Status: Abandoned Application

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Fitzgerald, Keif, Nikanorov, Alexander, Anukhin, Boris, Tyler, Steven
• Application Number:
  US11/353,391
• Publication Number:
  US 20070191926A1
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/825 having longitudinal struts
• CPC Class Codes: A61F 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

An expandable stent has larger cells located at the distal end of the stent than in the body portion so that a catheter balloon can more easily protrude into the cells to increase stent retention relative to the balloon. The intravascular stent has a plurality of cylindrical rings connected by links, the spacing of which is a factor in defining the cell size. The stent can be compressed or crimped onto a balloon catheter to a very low profile and maintain a high degree of stent retention due to increased spacing between rings in the region of the distal end ring.

Claims

1. A stent mounted on an expandable member of a catheter for use in a body lumen, comprising:

a plurality of cylindrical rings aligned along a common longitudinal axis and interconnected to form the stent, each cylindrical ring having a first delivery diameter and a second implanted diameter;

each cylindrical ring having a distal end and a proximal end and being spaced apart longitudinally to form a plurality of first cells; and

a distal end ring having a distal end and a proximal end and being spaced apart longitudinally from an adjacent ring to form a plurality of second cells for increasing stent retention relative to the expandable member.

2. The stent of claim 1, wherein the second cells are bigger than the first cells.

3. The stent of claim 1, wherein two distal end rings are spaced apart longitudinally to form a plurality of third cells.

4. The stent of claim 3, wherein the third cells are bigger than the first cells.

5. The stent of claim 3, wherein the third cells are substantially equal in size to the second cells.

6. The stent of claim 1, wherein there are fewer second cells between each distal end ring than first cells between adjacent rings.

7. The stent of claim 1, wherein there are two second cells between the distal end rings and an adjacent ring, and three first cells between adjacent rings.

9. The stent of claim 1, wherein the stent is formed from a tube.

10. The stent of claim 1, wherein the stent is formed from a metal alloy.

12. The stent of claim 1, wherein the stent is formed from a shape memory alloy.

14. The stent of claim 1, wherein the stent is formed from a superelastic or pseudoelastic metal alloy.

15. The stent of claim 14, wherein the stent is formed from the group of superelastic or pseudoelastic metal alloys consisting of nickel-titanium and nickel-titanium-vanadium.

16. The stent of claim 1, wherein at least a portion of the stent has a variable thickness configuration.

17. The stent of claim 1, wherein the cylindrical rings are interconnected by substantially straight links being substantially aligned with the longitudinal axis.

18. The stent of claim 1, wherein the distal end rings are interconnected to the adjacent cylindrical ring by a substantially straight link being substantially aligned with the longitudinal axis.

19. The stent of claim 1, wherein the distal end rings are interconnected by undulating links comprising at least one curved portion connected to a substantially straight portion, the substantially straight portion being substantially perpendicular to the stent longitudinal axis.

20. The stent of claim 19, wherein the substantially straight portion of the undulating links is perpendicular to the stent longitudinal axis when the stent is in the first delivery diameter configuration.

21. The stent of claim 19, wherein the substantially straight portion of the undulating links is perpendicular to the stent longitudinal axis when the stent is in the second implanted diameter configuration.

22. The stent of claim 19, wherein of the undulating links further comprise a plurality of curved portions.

23. The stent of claim 19, wherein the undulating links are configured to provide flexibility to the stent.

24. The stent of claim 1, wherein at least a portion of the stent is coated with a therapeutic agent.

11. The stent of claim 11, wherein the stent is formed from any of the group of metal alloys consisting of stainless steel, tantalum, nickel-titanium, cobalt-chromium and titanium.

13. The stent of claim 13, wherein the stent is formed from the group of shape memory alloys consisting of nickel-titanium and nickel-titanium-vanadium.

25. A stent mounted on an expandable member of a catheter for use in a body lumen, comprising:

a plurality of body rings aligned along a common longitudinal axis and interconnected to form the stent;

each body ring being spaced apart longitudinally to form a first gap; and

at least two distal end rings being spaced apart longitudinally to form a second gap for increasing stent retention relative to the expandable member.

26. The stent of claim 25, wherein the second gap is greater than the first gap.

27. The stent of claim 25, wherein a third distal end ring is spaced apart longitudinally from the second distal end ring to form a third gap.

28. The stent of claim 26, wherein the third gap is greater than the first gap.

29. The stent of claim 26, wherein the third gap is substantially equal to the second gap.

30. The stent of claim 25, wherein each body ring includes peaks that are in phase with peaks of adjacent body rings.

31. The stent of claim 25, wherein the rings are configured to provide flexibility to the stent.

32. The stent of claim 25, wherein the stent is formed from a tube.

33. The stent of claim 25, wherein the stent is formed from a metal alloy.

34. The stent of claim 33, wherein the stent is formed from any of the group of metal alloys consisting of stainless steel, tantalum, nickel-titanium, cobalt-chromium and titanium.

35. The stent of claim 25, wherein the body rings are interconnected by substantially straight links being substantially aligned with the longitudinal axis.

36. The stent of claim 25, wherein the distal end rings are interconnected to the adjacent body ring by a substantially straight link being substantially aligned with the longitudinal axis.

37. The stent of claim 25, wherein the distal end rings are interconnected by undulating links comprising at least one curved portion connected to a substantially straight portion, the substantially straight portion being substantially perpendicular to the stent longitudinal axis.

38. The stent of claim 37, wherein the substantially straight portion of the undulating links is perpendicular to the stent longitudinal axis when the stent is in the first delivery diameter configuration.

39. The stent of claim 37, wherein the substantially straight portion of the undulating links is perpendicular to the stent longitudinal axis when the stent is in the second implanted diameter configuration.

40. The stent of claim 37, wherein of the undulating links further comprise a plurality of curved portions.

41. The stent of claim 37, wherein the undulating links are configured to provide flexibility to the stent.

42. A flexible intravascular stent mounted on an expandable member of a catheter for use in a body lumen, comprising:

a plurality of body rings aligned along a common longitudinal axis and interconnected to form the stent, each body ring having a first delivery diameter and a second implanted diameter;

each body ring having a distal end and a proximal end and being spaced apart longitudinally to form a first gap;

a first distal end ring and a second distal end ring each having a distal end and a proximal end and being spaced apart longitudinally from an adjacent body ring to form second gap, the second gap being greater than the first gap; and

the first distal end ring being interconnected to the second distal end ring with a plurality of substantially straight links.

43. A flexible intravascular stent mounted on an expandable member of a catheter for use in a body lumen, comprising:

a plurality of body rings aligned along a common longitudinal axis and interconnected to form the stent, each body ring having a first delivery diameter and a second implanted diameter;

each body ring having a distal end and a proximal end and being spaced apart longitudinally to form a first gap;

a first distal end ring and a second distal end ring each having a distal end and a proximal end and being spaced apart longitudinally from an adjacent body ring to form second gap, the second gap being greater than the first gap; and

the first distal end ring being interconnected to the second distal end ring with a plurality of undulating links.