Rolling membrane with hydraulic recapture means for self expanding stent

• US 20060200221A1
• Filed: 03/03/2005
• Published: 09/07/2006
• Est. Priority Date: 03/03/2005
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Malewicz, Andrzej
• Granted Patent: US 7,632,296 B2
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/9661 the proximal portion of the stent or stent-graft is released first
• CPC Class Codes: A61F 2002/9528 for retrieval of stents
• CPC Class Codes: A61F 2002/9534 for repositioning of stents

Abstract

A medical device comprising a catheter having a retractable outer sheath and a rolling membrane. The catheter includes a catheter inner shaft about which a stent in a reduced diameter configuration may be disposed. A stent retaining region of the sheath is disposed about the stent to retain the stent in the reduced diameter state prior to delivery. The rolling membrane is engaged to a portion of the outer sheath at an engagement region. The rolling membrane is positioned between the catheter inner shaft and the outer sheath and prior to retraction of the sheath the rolling membrane is disposed about at least a proximal section of the stent and is rollingly retracted therefrom when the sheath is retracted to deliver the stent. The device also recaptures a stent by pressurizing a intra-catheter space, which results in the longitudinal movement of the outer sheath in a distal direction to recover and retain the stent.

Claims

1. A medical device comprising:

a catheter, the catheter having a distal portion and a proximal portion and comprising;

an inner shaft, the inner shaft having a distal portion and a proximal portion, wherein a portion of the distal portion of the inner shaft defines a stent receiving region;

a distal outer sheath, the distal outer sheath being about the inner shaft and being longitudinally movable relative thereto between an extended position, which is at least partially about the receiving region, and a retracted position;

a rolling membrane having a first end and a second end, the first end being sealingly engaged with the distal outer sheath and the second end being sealingly engaged with the inner shaft; and

an intra-catheter space, the intra-catheter space being defined by, at least in part, the rolling membrane and the distal outer sheath, the catheter being constructed and arranged such that the pressurization of the intra-catheter space causes the distal outer sheath to move distally relative to the inner shaft.

2. The medical device of claim 1, a portion of the distal outer sheath defining a stent retaining region at the distal portion of the catheter, the stent retaining region being disposed about the inner shaft and being longitudinally moveable relative thereto, the stent retaining region being moveable between the extended position and the retracted position, which is proximal to the extended position, wherein, when the distal outer sheath is in the extended position, the retaining region is disposed about the stent receiving region and, when it is in the retracted position, the distal outer sheath is proximally removed from the stent receiving region.

3. The medical device of claim 2, wherein, when the distal outer sheath is in its extended position, the engagement between the rolling membrane and the distal outer sheath is distally positioned relative to the engagement between the rolling membrane and the inner shaft and the rolling membrane is positioned between the inner shaft and the distal outer sheath, and wherein, when the distal outer sheath is in its retracted position, the engagement between the rolling membrane and the distal outer sheath is proximally positioned relative to the engagement between the rolling membrane and the inner shaft.

4. The medical device of claim 3, further comprising a proximal outer sheath, the proximal outer sheath being disposed about the inner shaft and being longitudinally fixed relative thereto, wherein the proximal outer sheath is positioned proximal to the stent receiving region and is sealingly engaged with the distal outer sheath.

5. The medical device of claim 4, the intra-catheter space being further defined by the inner shaft and the proximal outer sheath.

6. The medical device of claim 5, further comprising a pressure port, the pressure port being in communication with the intra-catheter space, wherein, when the distal outer sheath is in its retracted position, introduction of fluid through the pressure port into the intra-catheter space causes the distal outer sheath to longitudinally move toward its extended position.

7. The medical device of claim 6, further comprising a stent, the stent being expandable from a reduced state to an expanded state, the stent having a diameter in its reduced state that is less than the diameter in the expanded state, wherein, when the distal outer sheath is in the extended position, the stent is in the reduced state, disposed about the stent receiving region and wherein the stent has a proximal edge, a distal edge and a length measured from between the proximal edge and distal edge.

8. The medical device of claim 7, wherein, when the distal outer sheath is in the extended position, a portion of the rolling membrane is disposed about at least a proximal section of the stent.

9. The medical device of claim 8, the at least a proximal section of the stent defining about a half of the length of the stent as measured from the proximal edge.

10. The medical device of claim 8, the at least a proximal section of the stent defining about a 50 percent to about 100 percent of the length of the stent as measured from the proximal edge.

11. The medical device of claim 7, wherein the rolling membrane is defined by a single layer.

12. The medical device of claim 11, wherein the second end of the rolling membrane is engaged to the inner shaft at a point proximately positioned relative to the proximal edge of the stent.

13. The medical device of claim 7, wherein the pressure port is located in the proximal outer sheath.

14. The medical device of claim 12, wherein the second end of the rolling membrane is sealingly attached to a raised hub on the inner shaft.

15. The medical device of claim 7, wherein the first end of the rolling membrane is sealing attached to the distal end of the stent retaining region of the distal outer sheath.

16. The medical device of claim 7, wherein a distal portion of the proximal outer sheath and a proximal portion of the distal outer sheath overlap and are sealing engaged with one another via a sliding seal, the sliding seal maintaining a fluid seal between the proximal outer sheath and the distal outer sheath during longitudinal movement of the distal outer sheath relative to the proximal outer sheath and the inner shaft.

17. The medical device of claim 16, wherein the proximal outer sheath is sealingly attached to a raised hub on the inner shaft.

18. The medical device of claim 7, wherein at least a portion of the rolling membrane includes a lubricious coating applied thereto.

19. The medical device of claim 18, wherein the rolling membrane has an inner surface and an outer surface, the lubricious coating being applied to at least a portion of at least one of the inner surface and outer surface of the rolling membrane.

20. The medical device of claim 7, further comprising a stent securing hub, the stent securing hub being engaged to the inner shaft and being positioned immediately proximal of the stent receiving region.

21. The medical device of claim 20, wherein the rolling membrane is sealingly connected to the stent securing hub

22. The medical device of claim 21, wherein the stent securing hub is at least partially radiopaque.

23. The medical device of claim 22, wherein the stent securing member is configured to be detectable by at least one of the following detection modalities:

X-Ray, MRI, ultrasound, and any combination thereof.

24. The medical device of claim 7, wherein the distal outer sheath is at least partially constructed of at least one material of the group consisting of:

polyurethane, polytetrafluoroethylene, high density polyethylene, polyamide, polyimide, and any combinations thereof.

25. The medical device of claim 7, wherein the rolling membrane is at least partially constructed of at least one material of the group consisting of:

polyester, polyamide, polyethylene terephalate, crosslinked polyethylene, polyurethane, polyvinylchloride, polytetrafluoroethylene, nylon, polyether block amides, silicone, POC, polyether, and any combinations thereof.

26. The medical device of claim 7, wherein the stent is configured to be detectable by at least one of the following detection modalities:

X-Ray, MRI, ultrasound, and any combination thereof.

27. The medical device of claim 7, wherein at least a portion of the stent comprises at least one therapeutic agent.

28. The medical device of claim 1, wherein the catheter is a fixed-wire catheter.

29. The medical device of claim 1, wherein the inner shaft defines a guidewire lumen for passage of a guidewire therethrough.

30. The medical device of claim 1, wherein the distal outer sheath is welded to the rolling membrane.

31. The medical device of claim 1, wherein the distal outer sheath is bonded to the rolling membrane with an adhesive.