STENT FOR TREATING PATHOLOGICAL BODY VESSELS

• US 20010003801A1
• Filed: 02/16/1999
• Published: 06/14/2001
• Est. Priority Date: 01/31/1997
• Status: Active Grant

• Current Assignee: Thomas O. Hoover
• Original Assignee: Thomas O. Hoover
• Inventors: STRECKER, ERNST-PETER
• Granted Patent: US 6,485,524 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61B 17/12022 Occluding by internal devices, e.g. balloons or releasable wires plugging an opening in the wall of an organ A61B17/0057; occluders for the cervical canal A61F6/146; vas deferens occluders A61F6/20
• CPC Class Codes: A61B 17/12045 double occlusion, e.g. during anastomosis
• CPC Class Codes: A61B 17/12118 for positioning in conjunction with a stent
• CPC Class Codes: A61B 17/12172 having a pre-set deployed three-dimensional shape methods of manufacturing A61B2017/00526
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/954 for placing stents or stent-grafts in a bifurcation
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/077 having means to fill the space between stent-graft and aneurysm wall, e.g. a sleeve
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30467 using hook and loop-type fasteners
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2220/0083 using hook and loop-type fasteners
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/001 Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers

Abstract

A known method for treating pathological body vessels is the implantation of stents as an extended filament, by means of a catheter, which springs into a given form at the implantation site, as a result of its thermo-memory property or its elasticity. The invention relates to a new kind of stent, created in order to improve the flexibility and stability of the stent. This is achieved in that the stent filament or stent filaments are present in the form of at least two opposed spirals. The filament consists of a material with high elasticity or with thermo-memory properties. The stent can be covered with a structure made of pieces of fabric and/or fibers, and serves in this way as a stent graft. The new stent demonstrates high stability and flexibility. The stent can be introduced into a body vessel by means of a catheter lumen, which essentially corresponds to the outside diameter of the filaments forming the stent which expands in the point of destination to a larger-lumen tube-shaped implant.

Claims

1. A stent for treating pathological body vessels comprising at least two longitudinally extended filaments that can be delivered into a body vessel with an implantation device, the stent having a delivery state and an implanted state at the site of implantation such that at least two filaments form opposed spirals in the implanted state over at least a part of the longitudinal extent of the stent.

2. The stent of

claim 1

, further characterized in that the filaments comprise of a material with a superelastic property or a thermo-memory property.

3. The stent of

claim 1

, further characterized in that the filaments of opposed spirals comprise a single filament wire, which has a bend at a joining site of the two spirals.

4. The stent of

claim 1

, further characterized in that the filaments of opposed spirals are cut out in one piece from a tube-shaped workpiece.

5. The stent of

claim 1

, further characterized in that filaments of opposed spirals comprise two filament wires, which are joined together at least at one joining site.

6. The stent of

claim 5

, further characterized in that the two filaments forming opposed spirals are glued, soldered, or welded at the joining site.

7. The stent of

claim 5

, further characterized in that the two filaments forming opposed spirals are joined at a joining site with a sleeve engaged over the two filaments.

8. The stent of

claim 1

, further characterized in that joining site of the opposed spirals is positioned at a periphery of the stent in the implanted state of stent.

9. The stent of

claim 1

, further characterized in that opposed spirals are joined together at least partially at crossover points.

10. The stent of

claim 9

, further characterized in that the connection of opposed spirals at crossover points with threads arranged at least on one of filaments, whereby filaments can be moved in a limited manner relative to one another.

11. The stent of

claim 1

, wherein the stent comprises at least a third filament with a spiral form, the third filament has a pitch that differs at least partially relative to the at least two filaments.

12. The stent of

claim 1

, further characterized in that the filaments have the same direction of rotation over at least a part of the total length of stent.

13. The stent of

claim 1

, further characterized in that at least one filament has an arc-shaped segment running along a periphery of the stent.

14. The stent of

claim 13

, further characterized in that two filaments have arc-shaped segments opposed to one another at least over a part of the longitudinal extent of stent.

15. The stent of

claim 14

, further characterized in that the arc-shaped segments are joined together with a sleeve.

16. The stent of

claim 13

, further characterized in that two filaments have an alternating structure in which at least one complete spiral loop follows at least one arc-shaped segment, and filaments are displaced such that a spiral loop of one filament crosses over an arc-shaped segment of a second filament.

17. The stent of

claim 4

, further characterized in that the stent has an oval or “

D”

shaped lumen.

18. The stent of

claim 1

, further characterized in that filaments in their predetermined form are shaped in a double stent comprising of at least two secondary stents along at least part of the longitudinal extent of stent.

19. The stent of

claim 18

, further characterized in that secondary stents of the double stent are joined together with spiral loops formed of the filaments.

20. The stent of

claim 18

, further characterized in that the stent is shaped at least at a distal end such that the stent lumen has the approximate shape of a figure “

eight”

.

21. The stent of

claim 1

, further characterized by an elastically deformable membrane sheath.

22. The stent of

claim 21

, further characterized in that the membrane sheath is comprised of a textile fabric.

23. The stent of

claim 22

, further characterized in that reinforcement threads, preferably of metal, are included in the textile fabric structure of the membrane sheath.

24. The stent of

claim 1

, further characterized in that at least one of the filaments at least partially has a fabric structure projecting out from an outer periphery of the filament from fibers extending radially from the filament.

25. The stent of

claim 24

, further characterized in that the fabric structure or fibers extend from individual adjacent spirals or arc segments formed by filaments.

26. The stent of

claim 24

, further characterized in that at least one filament is enveloped with a fabric structures or radially projecting fibers.

27. The stent of

claim 26

, further characterized in that several filament parts, including the fabric structures or the radially projecting fibers, are twisted together into a single filament.

28. The stent of claims 26, further characterized in that the fabric structures or fibers radially projecting from filament are of different lengths.

29. The stent of

claim 28

, further characterized in that the fabric structures or fibers extend between adjacent spiral loops or arc segments formed by filaments that contact each other along a boundary line.

30. The stent of

claim 25

, further characterized in that fabric structures or fibers between spiral loops or arc segments formed by filaments overlap at least partially.

31. The stent of

claim 25

, further characterized in that the fabric structure comprises a textile structure.

32. The stent of claims 25, further characterized in that the fabric structure comprises a metal fabric.

33. The stent of

claim 25

, further characterized in that the fabric structure is cut to form fringe.

34. The stent of claims 25, further comprising overlapping fabric structure that are connected.

35. The stent of claims 25, further characterized in that a cross section of fabric structure is shaped to taper with increasing distance from the filament.

36. The stent of

claim 1

, further characterized in that a compact ring stent has fabric structures or fibers, which project inside or radially over an outer periphery of the stent.

37. The stent of

claim 1

, further characterized in that at least one of the filaments has a marking, to provide for an external observation of the stent.

38. The stent of

claim 1

, further characterized in that filaments form opposed spiraled loops that form an outer radius of the stent at intervals along the longitudinal extent of the stent.

39. A delivery device for implanting a stent in a body lumen comprising:

a catheter including an outer pushing device with an axial lumen through which an inner pushing device can be guided, the outer pushing device having on a distal end a support surface that supports a stent at a proximal end of the stent inside the catheter, the stent being for detachably joined at a distal end of the stent with the inner pushing device.

40. The device of

claim 39

, further characterized in that the inner pushing device has a screw thread that joins with the distal end of the stent.

41. The device of

claim 40

, further characterized in that the stent has a connector that attaches to a thread connection of inner pushing device.

42. The device of claims 39, further characterized by a connector that detachably joins with the proximal end of the stent are provided in the region of support surface of outer pushing device.

43. The device of

claim 39

, further characterized in that a fork for guiding filaments of the stent is provided as a distal support on the inner pushing device at a joining site of the filaments.

44. The device of

claim 42

, further characterized in that a forceps device is provided, which, during the implantation process, engages filaments in a rigid but detachable manner on a loop joining these filaments at the distal stent end.

45. The device of

claim 42

, further characterized in that, a hook element is provided, which can be joined in an axially rigid manner within catheter and is a fitting with a corresponding notch arranged in an end sleeve joining together filaments of stent at its proximal end.

46. A method of implanting a stent comprising:

providing a stent having a first filament and a second filament that have a delivery state and an implanted state in which the filaments form opposed spirals along a longitudinal axis of the stent;

inserting a catheter on which the stent is mounted in the delivery state into a body lumen; and

implanting the stent at a site in the body lumen such that the stent is released from the catheter and expands to the implanted state.

47. The method of

claim 46

wherein the step of providing a stent comprises cutting the stent from a workpiece with a laser.

48. The method of

claim 46

further comprising joining the two filaments at intervals along the longitudinal axis.

49. The method of

claim 46

wherein the providing step comprises forming at least two secondary stents with the filaments.

50. The method of

claim 46

further comprising providing a membrane extending along the longitudinal axis of the stent.