DELIVERY OF MEDICAL DEVICES

• US 20150066128A1
• Filed: 09/27/2013
• Published: 03/05/2015
• Est. Priority Date: 08/27/2013
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Losordo, Michael L., Skujins, Peter, Johnson, Garrett
• Granted Patent: US 9,827,126 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2/962 having an outer sleeve
• 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 2/97 the outer sleeve being splittable
• CPC Class Codes: A61F 2002/823 Stents, different from stent-grafts, adapted to cover an aneurysm
• CPC Class Codes: A61F 2002/9505 having retaining means other than an outer sleeve, e.g. male-female connector between stent and instrument
• CPC Class Codes: A61F 2002/9528 for retrieval of stents
• CPC Class Codes: A61F 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61M 25/0053 having a variable stiffness along the longitudinal axis, e.g. by varying the pitch of the coil or braid
• CPC Class Codes: A61M 25/008 Strength or flexibility characteristics of the catheter tip

Abstract

A stent delivery system can include a core member and a stent. The stent can be carried by an intermediate portion of the core member. The core member can have an elongate, spiral-cut tube extending proximally of the intermediate portion. The core member can have one or more flex zones having different bending stiffnesses.

Claims

1. A stent delivery system, comprising:

a core member having an intermediate portion and an elongate, spiral-cut tube extending proximally of the intermediate portion, the tube having first and second flex zones, the second flex zone being proximal of the first flex zone, and a transition zone between the first and second flex zones;

the first flex zone having a bending stiffness of less than 12 N*mm̂

2 so as to be navigable through the internal carotid artery bifurcation, the spiral cut of the tube in the first flex zone having a first pitch;

the second flex zone having a bending stiffness of greater than 60 N*mm̂

2, the spiral cut of the tube in the second flex zone having a second pitch different from the first pitch;

wherein the spiral cut of the tube in the transition zone changes from the first pitch to the second pitch in a series of pitch transitions, the spiral cut pitch in the transition zone increasing by an overall percent increase from the first pitch to the second pitch, such that the average overall percent increase achieved per transition is 15% or less; and

a stent carried by the intermediate portion.

2. The system of claim 1, wherein the pitch transitions of the spiral cut of the tube have a density along the transition zone greater than 1 transition per centimeter.

3. The system of claim 1, wherein the pitch of the spiral cut of the tube increases by over 150% from the first pitch to the second pitch in a proximal direction in the transition zone.

4. The system of claim 1, wherein the first flex zone length is greater than 60 mm.

5. The system of claim 1, wherein the second flex zone length is greater than 30 mm.

6. The system of claim 1, wherein the second flex zone bending stiffness is 60-100 N*mm̂

2.

7. The system of claim 1, wherein the first flex zone is navigable to the M1 bifurcation.

8. The system of claim 7, wherein the second flex zone is navigable to the common carotid artery.

9. The system of claim 1, further comprising a second transition zone distal of the first flex zone, the spiral cut of the tube in the second transition zone decreasing from the second pitch in a second series of pitch transitions, the second series of pitch transitions having a density along the second transition zone greater than five transitions per centimeter.

10. The system of claim 1, wherein a distal end of the first flex zone is spaced 8-12 mm from a proximal end of the stent.

11. The system of claim 10, wherein a distal end of the second flex zone is spaced 225-275 mm from a proximal end of the stent.

12. The system of claim 1, wherein the spiral cut of the tube prevails along a cut length of the tube, the cut length being greater than 50 cm.

13. The system of claim 12, wherein the spiral cut is contiguous along the cut length.

14. A stent delivery system, comprising:

a core member having an intermediate portion and an elongate, spiral-cut tube extending proximally of the intermediate portion, the tube having an uncut-tube bending stiffness and a first flex zone located near a distal end of the tube, and a transition zone extending proximally from the first flex zone;

the first flex zone having a bending stiffness of less than 5% of the uncut-tube bending stiffness so as to be navigable through the carotid siphon, the spiral cut of the tube in the first flex zone having a first pitch;

wherein the spiral cut of the tube in the transition zone increases from the first pitch in a proximal direction in a series of pitch transitions, the spiral cut pitch in the transition zone increasing by an overall percent increase from the first pitch, such that the average overall percent increase achieved per transition is 15% or less; and

a stent carried by the intermediate portion.

15. The system of claim 14, wherein the pitch transitions of the spiral cut of the tube have a density along the transition zone greater than 1 transition per centimeter.

16. The system of claim 14, wherein the pitch of the spiral cut of the tube increases by over 150% from the first pitch in a proximal direction in the transition zone.

17. The system of claim 14, wherein the first flex zone length is greater than 60 mm.

18. The system of claim 14, wherein the first flex zone is navigable to the M1 bifurcation.

19. The system of claim 14, further comprising a second transition zone distal of the first flex zone, the spiral cut of the tube in the second transition zone decreasing from the second pitch in a second series of pitch transitions, the second series of pitch transitions having a density along the second transition zone greater than five transitions per centimeter.

20. The system of claim 14, wherein a distal end of the first flex zone is spaced 8-12 mm from a proximal end of the stent.

21. The system of claim 14, wherein the spiral cut of the tube prevails along a cut length of the tube, the cut length being greater than 50 cm.

22. The system of claim 21, wherein the spiral cut is contiguous along the cut length.

23. The system of claim 14, wherein the tube has an outer diameter of 0.040″

or less, and a wall thickness of 0.010″

or less.

24. A stent delivery system, comprising:

a core member having an intermediate portion and an elongate, spiral-cut tube extending proximally of the intermediate portion, the tube having first and second flex zones, the second flex zone being proximal of the first flex zone, and a transition zone between the first and second flex zones;

the first flex zone having a bending stiffness of less than 220 N*mm̂

2 so as to be navigable through the aortic arch, the spiral cut of the tube in the first flex zone having a first pitch,

the second flex zone having a bending stiffness of greater than 250 N*mm̂

2, the spiral cut of the tube in the second flex zone having a second pitch different from the first pitch,

wherein the spiral cut of the tube in the transition zone changes from the first pitch to the second pitch in a series of pitch transitions, the spiral cut pitch in the transition zone increasing by an overall percent increase from the first pitch to the second pitch, such that the average overall percent increase achieved per transition is 10% or less; and

a stent carried by the intermediate portion.

25. The system of claim 24, wherein the pitch transitions of the spiral cut of the tube have a density along the transition zone greater than 1 transition per centimeter.

26. The system of claim 24, wherein the pitch of the spiral cut of the tube increases by over 35% from the first pitch to the second pitch in a proximal direction in the transition zone.

27. The system of claim 24, wherein the first flex zone length is greater than 200 mm.

28. The system of claim 24, wherein the second flex zone length is greater than 30 mm.

29. The system of claim 24, wherein the second flex zone bending stiffness is 250-310 N*mm̂

2.

30. The system of claim 24, wherein a distal end of the first flex zone is spaced 480-540 mm from a proximal end of the stent.

31. The system of claim 30, wherein a distal end of the second flex zone is spaced 780-820 mm from a proximal end of the stent.

32. The system of claim 24, wherein the spiral cut of the tube prevails along a cut length of the tube, the cut length being greater than 50 cm.

33. The system of claim 32, wherein the spiral cut is contiguous along the cut length.