Strain management in stent delivery system

• US 20070055338A1
• Filed: 05/10/2004
• Published: 03/08/2007
• Est. Priority Date: 05/09/2003
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Dorn, Jurgen
• Granted Patent: US 8,790,385 B2
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/9665 with additional retaining means
• CPC Class Codes: A61M 2025/0059 having means for preventing the catheter, sheath or lumens from collapsing due to outer forces, e.g. compressing forces, or caused by twisting or kinking
• CPC Class Codes: A61M 25/0102 Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod

Abstract

A percutaneous, transluminal system with a distal end for inserting into a body and a proximal end to remain outside the body, and comprising: an inner catheter which runs the length of the system and has a distal end and a proximal end, the inner catheter itself comprising: an inner tube (102); a wire coil (110) disposed around at least a portion of the inner tube, having a distal end, a proximal end, a distal region (114), an intermediate region and a proximal region (112); and an outer tube (124), having a distal end and a proximal end, disposed around at least a portion of the wire coil reinforcing member, characterized by: the wire coil having a closed-coil structure in the intermediate region and an open-coil structure in at least one of the distal region and the proximal region; and by a flow path for liquid from the proximal to the distal end of the system which includes a radially-extending portion through said open coil structure.

Claims

1. A percutaneous, transluminal system with a distal end for inserting into a body and a proximal end to remain outside the body, the system including an inner catheter, comprising:

an inner tube;

a wire coil disposed around at least a portion of the inner tube, having a distal region, an intermediate region and a proximal region, and including a closed-coil structure in the intermediate region and an open-coil structure in at least one of the distal region and the proximal region;

an outer tube disposed around at least a portion of the wire coil, and

a flow path for liquid from the proximal to the distal end of the system, including a radially-extending portion through the open-coil structure.

2. The system of claim 1, wherein the wire coil has an open-coil structure in both the distal region and the proximal region.

3. The system of claim 1, wherein the wire coil defines at least a portion of the liquid flow path to be a helical path defined by the adjacent turns of the coil.

4. The system of claim 1, wherein the wire coil defines at least a portion of the liquid flow path to be an annular path bounded by the inner tube and the adjacent turns of the coil.

5. The system of claim 1, wherein the outer tube is a shrink-tube constraining the wire coil.

6. The system of claim 1, wherein the outer tube comprises PTFE.

7. The system of claim 1, wherein the inner tube defines an inner guide-wire lumen.

8. The system of claim 1, further comprising a tip mounted to the inner tube at the distal end thereof.

9. The system of claim 1, wherein the inner tube defines a medical-device-receiving annulus around a distal portion of the inner tube, which is distal of the distal end of the wire coil and proximal of the distal end of the inner tube.

10. The system of claim 1, further including a lubricious coating on an outer surface of the outer tube.

11. The system according to claim 1, further comprising an outer sheath disposed around at least a portion of the length of said inner catheter, the outer sheath being retractable in a proximal direction relative to the inner catheter.

12. The system of claim 11, wherein the inner catheter is configured to resist an associated radially inward contraction of the outer sheath arising from proximal relative movement thereof.

13. The system of claim 11, wherein the outer sheath comprises a thermoplastic elastomeric material.

14. The system of claim 11 further comprising an actuating apparatus connected to a proximal end of the inner catheter and the outer sheath, configured to retract the outer sheath in a proximal direction relative to the inner catheter.

15. The system of claim 11 further comprising a medical device maintained in a medical-device receiving annulus inside the outer sheath near the distal end, the medical device being releasable by the retraction of the outer sheath in a proximal direction relative to the inner catheter.

16. The system of claim 15, wherein:

the medical device is held within the outer sheath and is positioned distal of the distal end of the wire coil;

the medical device is maintained in a radially compressed first state by the outer sheath being disposed about at least a portion of the medical device;

during retraction of the outer sheath, the medical device is prevented by the wire coil from moving with the outer sheath in a proximal direction; and

when the outer sheath is retracted in a proximal direction relative to the inner catheter, the medical device is released for expansion to a radially less compressed second state.

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

45. The delivery system according to claim 1S, wherein the wire coil is comprised of a material selected from the group consisting essentially of nickel titanium alloy, stainless steel, and combinations thereof.

18. A delivery system for a medical implant, comprising:

an inner catheter including a wire coil disposed between an inner tube and an outer tube, the wire coil having gaps between turns of the coil at a proximal and a distal region thereof;

an outer catheter disposed about the inner catheter; and

a flow path for liquid from a proximal end to a distal end of the system, the flow path including a radially extending portion through the gaps.

19. The delivery system according to claim 18, wherein the outer tube is disposed over an intermediate region of the wire coil having a closed-coil structure.

20. The delivery system according to claim 19, wherein the outer tube comprises PTFE configured to fit tightly over the wire coil preventing adjacent turns of the coil from overlapping.

21. The delivery system according to claim 20, wherein the flow path in the intermediate region is bounded by the inner tube and adjacent turns of the coil.

22. The delivery system according to claim 18, wherein the flow path includes a helical path between the adjacent turns of the coil and the outer tube.

23. The delivery system according to claim 18, further comprising a pusher element attached to the inner tube proximal of a medical implant bed, the pusher element including a flange portion and a shoulder portion.

24. The delivery system according to claim 23, wherein an adhesive is disposed between at least a section of the shoulder portion and the inner tube.

25. The delivery system according to claim 23, wherein a distal end of wire coil is disposed over at least a section of the shoulder portion to secure the position of the pusher element with respect to the inner tube.

26. The delivery system according to claim 23, wherein the pusher element comprises PEEK.

27. The delivery system according to claim 23, further comprising a marker attached to a distal end of the outer catheter, wherein the pusher element comprises a radiopaque material.

28. The delivery system according to claim 18, wherein the inner tube defines a medical implant bed at a distal end thereof.

29. The delivery system according to claim 28, further comprising a self-expanding stent, having a radially expanded configuration and a radially compressed configuration, wherein the stent is disposed about the medical implant bed and is maintained in the collapsed configuration by the outer catheter.

30. The delivery system according to claim 29, further comprising a pusher element, including a flange portion, attached to the inner tube proximal of the stent bed, the flange portion abutting a proximal end of the stent preventing proximal movement thereof.

31. The delivery system according to claim 18, further comprising a tip connected to a distal end of the system, the tip including a guide wire lumen.

32. The delivery system according to claim 31, wherein the tip is a tapered extension of one of the inner tube and outer sheath.

33. The delivery system according to claim 31, wherein the tip is a separate element adhesively bonded to the inner tube.

34. The delivery system according to claim 31, wherein the tip comprises polyurethane.

35. The delivery system according to claim 18, further comprising a push rod disposed about a proximal end of the inner tube, a distal end of the push rod abutting a proximal end of the wire coil.

36. The delivery system according to claim 18, further comprising an actuating apparatus connected to a proximal end of both the inner catheter and outer catheter, the actuating apparatus configured to proximally move the outer catheter relative to the inner catheter.

37. The delivery system according to claim 36, further comprising a lubricous coating disposed between the outer tube and the outer catheter.

39. The delivery system according to claim 18, wherein the outer tube comprises PTFE and the outer catheter comprises HYTREL, further comprising a lubricious silicone material disposed between the outer tube and outer catheter.

41. The delivery system according to claim 18, wherein the gaps in the proximal region are proximal of a proximal end of the outer tube and the gaps in the distal region are distal of a distal end of the outer tube.

42. The delivery system according to claim 18, wherein the outer catheter is configured for tight disposition over the outer tube such that no radial gap is present therebetween.

43. The delivery system according to claim 18, wherein the outer catheter is circumferentially pre-stressed such that the inside diameter thereof is less than the outside diameter of the outer tube.

44. The delivery system according to claim 18, wherein the inner tube is comprised of a material selected from the group consisting essentially of polymers, metals, and combinations thereof.

46. The delivery system according to claim 18, wherein the wire coil imparts radial, torsional and compressive reinforcement to the inner tube.

48. The method according to claim 46, wherein the inner catheter is disposed closely inside the outer catheter to support the outer catheter during the retracting such that diametrical contraction and longitudinal expansion of the outer catheter is generally inhibited during the retracting step.

49. The method according to claim 46, wherein a first marker band is attached to a distal end of the outer catheter and a second marker band is attached to the inner catheter adjacent a distal end of the wire coil, the retracting step further comprising aligning the first marker band with the second marker band to confirm deployment of the medical implant.

38. The delivery system according to claim is, further comprising a first marker band attached to a distal end of the outer catheter and;

a second marker band attached to the inner catheter adjacent a distal end of the wire coil.

40. The delivery system according to claim IS, wherein the wire coil extends beyond the outer tube both proximally and distally approximately 10 mm.

47. A method of delivering a medical implant to a body lumen, comprising:

inserting a medical implant delivery system into the body lumen, the system including an inner catheter having a wire coil disposed between an inner tube and all outer tube, the wire coil having gaps between turns of the coil at a proximal and a distal region thereof, an outer catheter disposed about the inner catheter, and a flow path for liquid from a proximal end to a distal end of the system, the flow path including a radially extending portion through the gaps;

injecting visualizing fluid into the proximal end of the delivery system, the visualizing fluid moving through the flow path and exiting the distal end of the system; and

retracting the outer catheter proximally relative to the inner catheter to release a medical implant disposed between the outer catheter and inner catheter at the distal end of the delivery system.