Combined shaped balloon and stent protector

• US 20020120320A1
• Filed: 01/04/2001
• Published: 08/29/2002
• Est. Priority Date: 01/04/2001
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Wang, Lixiao, Chen, John Jianhua
• Granted Patent: US 6,764,504 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve
• CPC Class Codes: A61M 2025/1059 having different inflatable sections mainly depending on the response to the inflation pressure, e.g. due to different material properties with different compartments A61M2025/1072
• CPC Class Codes: A61M 25/1002 characterised by balloon shape A61M25/1006, A61M25/1009 take precedence

Abstract

A stent delivery catheter comprising a catheter shaft and balloon engaged thereto. The balloon being inflatable from a first inflation state to a first expanded state as well as to a second expanded state. The balloon having a stent mounting region for retaining and delivery of a stent therefrom, and at least one adjacent region. The stent mounting region having a first diameter and the at least one adjacent region having a second diameter. In the first inflation state the first diameter being less than the second diameter. In the first expanded state the first diameter being no greater than the second diameter. In the second expanded state the first diameter being greater than the second diameter. The stent being retained on the stent mounting region by engagement of the at least one adjacent portion and at least one retractable stent retaining sleeve.

Claims

1. A stent delivery catheter, the catheter comprising:

a catheter shaft, and

a balloon, the balloon being mounted to the catheter shaft, the balloon being inflatable to a first inflation state, to a second inflation state, the balloon having a stent mounting region, and an adjacent region, the stent mounting region having a stent mounting region diameter and the adjacent region having an adjacent region diameter;

the balloon further having an inflation curve wherein when the balloon is in the first inflation state the stent mounting region diameter is less than the adjacent region diameter, in the second inflation state the stent mounting region diameter is substantially the same as the adjacent region diameter.

2. The stent delivery catheter of claim 1 further comprising a stent, the stent being disposed about at least a portion of the stent mounting region, the stent being expandable from an unexpanded state to a first stent expanded state, the stent further comprising a stent center, a first stent end and a second stent end.

3. The stent delivery catheter of claim 2 further comprising a stent retaining sleeve, the stent retaining sleeve having a stent retaining portion removingly disposed about at least one end of the stent and a catheter engagement portion engaged to a portion of the catheter shaft adjacent to the balloon.

4. The stent delivery catheter of claim 2 further comprising a first stent retaining sleeve and a second stent retaining sleeve, the first stent retaining sleeve having a stent retaining portion removingly disposed about the first stent end and a catheter engagement portion engaged to a first portion of the catheter shaft, the second stent retaining sleeve having a stent retaining portion removingly disposed about the second stent end and a catheter engagement portion engaged to a second portion of the catheter shaft.

5. The stent delivery catheter of claim 4 wherein when the balloon is expanded from the first inflation state to the second inflation state the stent is expanded from the unexpanded state to the first stent expanded state.

6. The stent delivery catheter of claim 5 wherein the stent mounting region is characterized as having a stepped compliance curve and the adjacent region is characterized as having a substantially linear compliance curve, the stepped compliance curve being characterized by a low pressure segment defined by a low inflation pressure range, said low pressure segment being generally collinear with a corresponding segment of the generally linear compliance curve of the at least one adjacent region which is defined by said low inflation pressure range, a transition segment during which the balloon expands rapidly relative to the at least one adjacent region and a high pressure segment during which the compliance curve of the stent mounting region expands slowly relative to the transition segment.

7. The stent delivery catheter of claim 6 wherein when the balloon is inflated to the second inflation state the stent mounting region is expanded according to the transition segment of the stepped compliance curve.

8. The stent delivery catheter of claim 5 wherein when the balloon is inflated to the second inflation state the stent mounting region is expanded according to the low pressure segment of the stepped compliance curve.

9. The stent delivery catheter of claim 4 wherein when the stent is expanded from the unexpanded state to the first stent expanded state the first stent retaining sleeve is configured to retract off of the first stent end, the second stent retaining sleeve is configured to retract off of the second stent end thereby releasing the stent from the first and second stent retaining sleeves.

10. The stent delivery catheter of claim 1 wherein the balloon further comprises a third inflation state, in the third inflation state the stent mounting region diameter being greater than the adjacent region diameter.

11. The stent delivery catheter of claim 10 wherein the stent further comprises a second stent expanded state, such that when the balloon is expanded to the third inflation state the stent is expanded to the second stent expanded state.

12. The stent delivery catheter of claim 5 wherein the balloon further comprises a third inflation state, in the third inflation state the stent mounting region diameter being greater than the adjacent region diameter.

13. The stent delivery catheter of claim 12 wherein when the balloon is inflated to the third inflation state the stent mounting region is expanded according to the transition segment of the stepped compliance curve.

14. The stent delivery catheter of claim 12 wherein when the balloon is inflated to the third inflation state the stent mounting region is expanded according to the high pressure segment of the stepped compliance curve.

15. The stent delivery catheter of claim 1 wherein when the balloon is in the first inflation state the stent mounting region diameter is about 1.5 mm to about 2.5 mm.

16. The stent delivery catheter of claim 1 wherein when the balloon is in the first inflation state the adjacent region diameter is about 1.65 mm to about 2.65 mm.

17. The stent delivery catheter of claim 1 wherein when the balloon is in the second inflation state the adjacent region diameter has a range of about 2.0 mm to about 3.75 mm.

18. The stent delivery catheter of claim 10 wherein when the balloon is in the third inflation state the stent mounting region diameter has a range of about 2.75 mm to about 4.25 mm and the adjacent region diameter has a range of about 2.0 mm to 3.75 mm.

19. The stent delivery catheter of claim 1 wherein the balloon is constructed from at least one member of the group consisting of:

thermoplastic polyurethane, polyethylene, polyesters, poly(butylene terephthalate)-block-poly(tetramethylene oxide) polymers, polyetherether ketone, block copolymers of polyether polymers and polyamides, block copolymers of polyether and polyester polymers, polyamides, block polyimides, polytetrafluoroethylene, polyolefins, silicone elastomers, and any combinations thereof.

20. The stent delivery catheter of claim 19 wherein the balloon is at least partially constructed from PEBAX.

21. The stent delivery catheter of claim 10 wherein when the balloon is inflated to a first pressure of 1 atm to about 3 atm the balloon is in the first inflation state, when the balloon is inflated to a second pressure of more than about 3 atm to about 6 atm the balloon is in the first inflation state, when the balloon is inflated to a third pressure of about 12 atm to about 16 atm the balloon is in the third inflation state.

22. The stent delivery catheter of claim 12 wherein when the balloon is inflated to a first pressure of greater than about 3 atm to about 6 atm the stent mounting region is in the low pressure segment of the stepped compliance curve and when the balloon is inflated to a third pressure of about 12 atm to about 16 atm the stent mounting region is in the high pressure segment of the stepped compliance curve.

23. The stent delivery catheter of claim 1 wherein the adjacent region further comprises a proximal adjacent region and a distal adjacent region.

25. The stent delivery catheter of claim 24 wherein the stent mounting region of the balloon is characterized as having a stepped compliance curve.

26. The stent delivery catheter of claim 25 wherein each of the adjacent regions of the balloon are characterized as having a substantially linear compliance curve.

27. The stent delivery catheter of claim 24 wherein when the balloon is in the second inflation state the stent mounting region diameter is about 0.05 mm to about 0.25 mm less than the adjacent region diameter.

28. The stent delivery catheter of claim 24 wherein the balloon is further characterized as having a third inflation state, when the balloon is inflated to the third inflation state the stent mounting region diameter is greater than the adjacent region diameter.

29. The stent delivery catheter of claim 24 wherein when the balloon is in the third inflation state the stent mounting region diameter is about 0.05 mm to about 0.25 mm greater than the adjacent region diameter.

24. A stent delivery catheter comprising:

a catheter shaft;

a balloon, the balloon being mounted to a distal portion of the catheter shaft, the balloon being inflatable to a first inflation state to a second inflation state, the balloon having a stent mounting region, and a pair of balloon regions adjacent to the stent mounting region, the pair of balloon regions comprising;

a proximal adjacent region and a distal adjacent region, the stent mounting region having a stent mounting region diameter and each of the adjacent regions having an adjacent region diameter, in the first inflation state the stent mounting region diameter being less than the adjacent region diameter, in the second inflation state the stent mounting region diameter being no greater than the adjacent region diameter;

a stent, the stent being disposed about at least a portion of the stent mounting region, the stent being expandable from an unexpanded state to a first stent expanded state, the stent further comprising a stent center, a first stent end and a second stent end; and

a proximal stent retaining sleeve and a distal stent retaining sleeve, each of the stent retaining sleeves having a stent retaining portion and a catheter engagement portion, the stent retaining portion of the distal stent retaining sleeve being removingly disposed about the first stent end, the stent retaining portion of the proximal stent retaining sleeve being removably disposed about the second stent end, the catheter engagement portion of the distal stent retaining sleeve being engaged to a portion of the catheter shaft proximate to the distal adjacent region of the balloon, the catheter engagement portion of the proximal stent retaining sleeve being engaged to a portion of the catheter shaft proximate to the proximal adjacent region of the balloon, whereby when the balloon is inflated from the first inflation state to the second inflation state the at least one stent retaining sleeve is retracted off of the at least one end of the stent.

30. A stent delivery catheter comprising:

a catheter shaft;

a balloon, the balloon being mounted to a distal portion of the catheter shaft, the balloon being inflatable to a first inflation state, to a second inflation state, and to a third inflation state, the balloon having a stent mounting region and a pair of adjacent end regions, the stent mounting region having a stent mounting region diameter and the pair of end regions each having an end region diameter, in the first inflation state the stent mounting region diameter being less than the end region diameter, in the second inflation state the stent mounting region diameter being no greater than the end region diameter, in the third inflation state the stent mounting region diameter being greater than the end region diameter; and

a stent, the stent being disposed about at least a portion of the stent mounting region, the stent being expandable from an unexpanded state to an expanded state, the stent further comprising a stent center, a first stent end and a second stent end.

31. The stent delivery catheter of claim 30 further comprising a pair of stent retaining sleeves, each of the stent retaining sleeves having:

a stent retaining portion removingly disposed about one of the ends of the stent, an end region overlaying portion and a catheter engagement portion engaged to a portion of the catheter shaft adjacent to the balloon, whereby when the balloon is inflated from the first inflation state to the second inflation state the stent retaining sleeves are retracted off of the ends of the stent and the end regions of the balloon.

32. The stent delivery catheter of claim 31 wherein when the balloon is in the first inflation state and the second inflation state the pair of end regions are engaged to the first stent end and the second stent end respectively, thereby preventing longitudinal movement of the stent relative to the balloon.

33. A method of delivering a stent using the stent delivery catheter of claim 30 comprising the following steps:

inserting the distal portion of the catheter shaft into a body lumen;

advancing the distal portion of the catheter to a legion sight;

inflating the balloon to the first inflation state;

inflating the balloon to the second inflation state by supplying the balloon with an inflation pressure of between about 3 to about 7 atmospheres;

retracting the stent retaining sleeves from the ends of the stent and from the adjacent end regions of the balloon;

inflating the balloon from the second inflation state to the third inflation state by supplying the balloon with an inflation pressure of between about 12 to about 16 atmospheres, thereby expanding the stent to the stent expanded state;

collapsing the balloon; and

withdrawing the distal portion of the catheter from the body lumen.

35. The medical balloon of claim 34 wherein when the balloon is expanded from the first inflation state to the second inflation state the balloon is pressurized to a pressure sufficient to expand a stent mounted over the stent mounting region to a first stent expanded state.

36. The medical balloon of claim 34 wherein the stent mounting region has a stepped compliance curve and each of the end regions have a substantially linear compliance curve, the stepped compliance curve being characterized by a low pressure segment defined by a low inflation pressure range, said low pressure segment being generally collinear with a corresponding segment of the generally linear compliance curve of the end regions which is defined by said low inflation pressure range, a transition segment during which the balloon expands rapidly relative to the end regions and a high pressure segment during which the compliance curve of the stent mounting region expands slowly relative to the transition segment.

37. The medical balloon of claim 36 wherein when the balloon is inflated to the second inflation state the stent mounting region is expanded according to the transition segment of the stepped compliance curve.

38. The medical balloon of claim 36 wherein when the balloon is inflated to the second inflation state the stent mounting region is expanded according to the low pressure segment of the stepped compliance curve.

39. The medical balloon of claim 34 wherein the balloon further comprises a third inflation state, in the third inflation state the diameter of the stent mounting region is greater than the diameter of the at least one adjacent region.

40. The medical balloon of claim 39 wherein when the balloon is inflated to the third inflation state the stent mounting region is expanded according to a transition segment of the stepped compliance curve.

41. The medical balloon of claim 39 wherein when the balloon is inflated to the third inflation state the stent mounting region is expanded according to the high pressure segment of the stepped compliance curve.

42. The medical balloon of claim 34 wherein when the balloon is in the first inflation state the diameter of the stent mounting region is about 1.5 mm to about 2.5 mm.

43. The medical balloon of claim 34 wherein when the balloon is in the first inflation state the end regions have a diameter of about 1.65 mm to about 2.65 mm.

44. The medical balloon of claim 34 wherein when the balloon is in the second inflation state the end regions have a diameter of about 2.0 mm to about 3.75 mm.

45. The medical balloon of claim 34 wherein when the balloon is in the third inflation state the diameter of the stent mounting region is about 2.75 mm to about 4.25 mm and the end regions have a diameter of about 2.0 mm to 3.75 mm.

46. The medical balloon of claim 34 wherein the stent mounting region has a hardness value greater than that of the adjacent end regions.

47. The medical balloon of claim 34 further comprising a coating, the coating being positioned on at least a portion of the adjacent end regions of the balloon and not on the stent mounting region, the coating effective to restrict expansion of the end regions at the predetermined inflation pressure..

34. A medical balloon comprising:

a stent mounting region and a pair of adjacent end regions,

the balloon being inflatable from a first inflation state to a second inflation state, in the first inflation state the stent mounting region having a diameter less than that of the adjacent end regions,

the stent mounting region having a first rate of expansion and the at adjacent region having a second rate of expansion, the first rate of expansion being greater than the second rate of expansion, whereby when the balloon is inflated from the first inflation state to the second inflation state by a predetermined inflation pressure the diameter of the stent mounting region is at least as large as the diameter of the adjacent and regions.

48. The medical balloon of claim 52 wherein the coating is selected from at least one member of the group consisting of:

, poly(ethylene terephthalate) (commonly referred to as PET), polyimide, thermoplastic polyimide, polyamides, polyesters, polycarbonates, polyphenylene sulfides, polypropylene and rigid polyurethanes.