Device Delivery System With Two Stage Withdrawal

• US 20090036966A1
• Filed: 08/01/2007
• Published: 02/05/2009
• Est. Priority Date: 08/01/2007
• Status: Active Grant

• Current Assignee: Merit Medical Ireland, Limited (Merit Medical Systems, Inc.)
• Original Assignee: Cappella Inc. (ArraVasc Limited)
• Inventors: Kelly, Damian, Slattery, David, O'Connor, Therese, Gilmore, Michael
• Granted Patent: US 8,252,035 B2
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/9665 with additional retaining means

Abstract

A medical device delivery system provides for a two-stage withdrawal of a deflated balloon portion of a catheter and the remains of a ruptured sheath. The deflated balloon portion is withdrawn from within an expanded medical device a predetermined distance before the remains of the ruptured sheath begins being removed from between the expanded device and a vessel wall. Initiating removal of the deflated balloon portion before the sheath reduces a total amount of drag that is exerted against a self-expanding medical device that has been deployed in a vessel.

Claims

1. A delivery system, comprising:

a catheter having a distal end and a distal portion;

a balloon portion disposed at the distal portion of the catheter;

a first catheter stop disposed on the catheter at a first location a first distance from the distal end of the catheter;

a second catheter stop disposed on the catheter a second distance from the distal end of the catheter, the second distance greater than the first distance;

a sheath ring slidably disposed on the catheter between the first and second catheter stops; and

a sheath disposed about the balloon portion, the sheath having a distal portion and a proximal portion, the proximal portion of the sheath coupled to the sheath ring.

2. The delivery system of claim 1, further comprising:

a medical device disposed about the balloon and restrained by the sheath.

3. The delivery system of claim 2, wherein the medical device is a self-expanding stent.

4. The delivery system of claim 2, wherein a distance L between the first and second catheter stops is determined as a function of at least one of:

a length of the medical device; and

a length of the balloon portion.

5. The delivery system of claim 2, wherein the medical device is a self-expandable device.

6. The delivery system of claim 1, wherein at least one of the first and second catheter stops and the sheath ring comprises radio-opaque material.

7. The delivery system of claim 1, wherein at least one of the first and second catheter stops comprises a ring disposed about the catheter.

8. The delivery system of claim 1, wherein at least one of the first and second catheter stops is glued to the catheter.

9. The delivery system of claim 1, wherein the sheath is glued to the sheath ring.

10. the delivery system of claim 9, wherein:

the sheath comprises at least one opening through which the glue is provided.

11. A delivery system, comprising:

a catheter having a distal end and a distal portion;

a balloon portion disposed on the distal portion of the catheter;

a first catheter stop disposed on the catheter at a first location a first distance from the distal end of the catheter;

a sheath ring slidably disposed on the catheter proximal to the first catheter stop; and

a sheath disposed about the balloon portion and attached to the sheath ring.

12. The delivery system of claim 11, wherein the sheath is of a predetermined length and comprises a distal portion and a proximal portion, and wherein:

the sheath ring is attached to the sheath at the proximal portion of the sheath; and

the first distance is determined as a function of at least one of a length of the balloon portion and a length of the sheath.

13. The delivery system of claim 11, further comprising:

a second catheter stop disposed on the catheter at a second distance from the distal end of the catheter, the second distance greater than the first distance.

14. The delivery system of claim 11, further comprising:

a medical device disposed about the balloon portion and restrained by the sheath.

15. The delivery system of claim 14, wherein the medical device is a self-expanding stent.

16. The delivery system of claim 14, wherein a length of the sheath is determined as a function of at least one of:

a length of the balloon portion; and

a length of the medical device.

17. The delivery system of claim 14, wherein:

a distance which the proximal portion of the sheath extends beyond the location of the first catheter stop is determined as a function of at least one of;

a length of the balloon portion; and

a length of the medical device.

18. The delivery system of claim 17, further comprising:

a second catheter stop disposed on the catheter at a second location a second distance from the distal end of the catheter,

wherein the second distance is greater than the first distance.

19. The delivery system of claim 18, wherein:

a difference between the first and second distances is determined as a function of at least one of;

a length of the balloon portion; and

a length of the medical device.

20. The delivery system of claim 18, wherein:

the second location is substantially adjacent the sheath ring as held in place by the proximal portion of the sheath.

21. A system, comprising:

a catheter having a distal end and a distal portion;

rupturing means disposed at the distal portion of the catheter;

sliding means slidably coupled to the catheter;

constraining means, disposed about the rupturing means, and coupled to the sliding means; and

first stopping means, coupled to the catheter, for stopping movement of the sliding means.

22. The system of claim 21, wherein the first stopping means are located at a first location at a first distance from the distal end of the catheter.

23. The system of claim 21, further comprising:

a self-expanding medical device disposed about the rupturing means, wherein the medical device is held in place by the constraining means.

24. The system of claim 23, further comprising:

second stopping means coupled to the catheter;

wherein the sliding means is limited to a space between the first and second stopping means along the catheter.

25. The system of claim 24, wherein the first stopping means are located at a first distance from the distal end of the catheter and the second stopping means are located at a second location a second distance from the distal end of the catheter, the second distance greater than the first distance, wherein the second distance is determined as a function of at least one of:

the first distance;

a length of the constraining means; and

a length of the medical device.

26. The system of claim 21, wherein the first stopping means comprise one of:

a ring attached to the catheter; and

a plurality of blocks disposed about an outer circumference of the catheter.

27. The system of claim 26, wherein the ring attached to the catheter comprises a plurality of portions.

28. The system of claim 21, wherein the constraining means comprise:

a sheath having a distal portion and a proximal portion.

29. The system of claim 28, wherein the proximal portion of the sheath is attached to the sliding means.

30. The system of claim 29, wherein the sheath is glued to the sliding means.

31. The system of claim 29, wherein the sliding means comprise a ring.

32. The system of claim 31, wherein the ring comprises a plurality of portions.

33. A method of delivering a medical device to a predetermined location in a vessel of a body, the method comprising:

constraining the medical device in a compressed state on a delivery system;

maneuvering the delivery system to position the constrained medical device substantially adjacent to the predetermined location;

releasing the medical device from its constrained to deploy substantially at the predetermined location in the vessel; and

withdrawing a first portion of the delivery system, followed by withdrawal of a second portion of the delivery system, by operation of a continuous movement of the delivery system.

34. The method of claim 33, wherein the medical device is a self-expanding stent, further comprising:

constraining the stent with a sheath.

35. The method of claim 34, further comprising:

providing a balloon portion on the delivery system;

mounting the stent on the balloon portion while constraining the stent in its compressed state by the sheath,

wherein releasing the stent from the sheath comprises;

inflating the balloon portion sufficient to rupture this sheath.

36. The method of claim 34, further comprising:

slidably coupling the sheath to the delivery system.

37. A delivery system, comprising:

a catheter having a distal end and a distal portion;

a balloon portion disposed on the distal portion of the catheter; and

a sheath disposed about the balloon portion and coupled to the catheter at a location proximal to the balloon portion,

wherein the sheath comprises a bellows portion having a compressed length and an expanded length.

38. The delivery system of claim 37, wherein the expanded length of the bellows portion is determined as a function of a length of the balloon portion.

39. The delivery system of claim 37, wherein:

the sheath is attached directly to the catheter.

40. The delivery system of claim 39, wherein the sheath is glued to the catheter.

41. The delivery system of claim 37, further comprising:

a medical device disposed about the balloon portion and restrained by the sheath.

42. The delivery system of claim 41, wherein the medical device is a self-expanding stent.

43. The delivery system of claim 41, wherein the expanded length of the bellows portion is determined as a function of at least one of:

a length of the balloon portion; and

a length of the medical device.

44. The delivery system of claim 37, further comprising:

a first catheter stop disposed on the catheter at a first location a first distance from the distal end of the catheter; and

a sheath ring slidably disposed on the catheter at a location proximal to the first catheter stop,

wherein the sheath is attached to the sheath ring.

45. A delivery system, comprising:

a catheter having a distal end and a distal portion;

a balloon portion disposed on the distal portion of the catheter;

a sheath disposed about the balloon portion and having proximal and distal ends; and

a tether coupling the proximal end of the sheath to a location on the catheter at a location proximal to the balloon portion.

46. The delivery system of claim 45, wherein the tether is wrapped about the catheter in a configuration comprising a compressed length and an expanded length.

47. The delivery system of claim 46, wherein the expanded length of the tether is determined as a function of a length of the balloon portion.

48. The delivery system of claim 45, wherein the tether comprises:

a spring having a compressed length and an expanded length.

49. The delivery system of claim 48, wherein the expanded length of the spring is determined as a function of a length of the balloon portion.

50. The delivery system of claim 45, further comprising:

a medical device disposed about the balloon portion and restrained by the sheath.

51. The delivery system of claim 50, wherein the medical device is a self-expanding stent.

52. The delivery system of claim 50, wherein an expanded length of the tether is determined as a function of at least one of:

a length of the balloon portion; and

a length of the medical device.

53. A delivery system, comprising:

a catheter having a distal end and a distal portion;

a balloon portion disposed on the distal portion of the catheter;

a sheath disposed about the balloon portion and the catheter;

a plurality of sheath guides disposed on an interior surface of the sheath; and

a catheter rail disposed on the catheter and engaged with at least one sheath guide of the plurality of sheath guides, the catheter rail comprising a predetermined pitch length.

54. The delivery system of claim 53, wherein the predetermined pitch length is determined as a function of a length of the balloon portion.

55. The delivery system of claim 53, further comprising:

a medical device disposed about the balloon portion and restrained by the sheath.

56. The delivery system of claim 55, wherein the medical device is a self-expanding stent.

57. The delivery system of claim 55, wherein the predetermined pitch length is determined as a function of at least one of:

a length of the sheath;

a length of the balloon portion; and

a length of the medical device.

58. The delivery system of claim 53, wherein the catheter rail is integral with the catheter.

59. The delivery system of claim 53, wherein the catheter rail is a separate component attached to the catheter.

60. The delivery system of claim 53, wherein the plurality of sheath guides comprises a spiral assembly coupled to an interior surface of the sheath.