Medical implant having a curlable matrix structure

• US 20050209678A1
• Filed: 01/19/2005
• Published: 09/22/2005
• Est. Priority Date: 07/19/2002
• Status: Active Grant

• Current Assignee: USSC Medical GmbH (Medtronic Plc)
• Original Assignee: Dendron GmbH (Medtronic Plc)
• Inventors: Henkes, Hans, Flesser, Achim, Speder, Jurgen, Bodenburg, Ralph, Kontek, Ronald
• Granted Patent: US 7,300,458 B2
• Time in Patent Office: Days
• US Class Current: 623/1.120
• CPC Class Codes: A61B 17/12118 for positioning in conjunction with a stent
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 2017/12063 electrolytically detachable
• CPC Class Codes: A61B 2017/2215 having an open distal end
• 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 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• 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 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/9528 for retrieval of stents
• CPC Class Codes: A61F 2002/9534 for repositioning of stents
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers

Abstract

A medical implant, having a proximal and a distal end, that is preformed to assume a superimposed structure at an implantation site but can be made to take on a volume-reduced form making it possible to introduce it by means of a micro-catheter and a guide wire arranged at the proximal end, with the implant in its superimposed structure assuming the form of a longitudinally open tube and having a mesh structure of interconnected strings or filaments. The implant has a tapering structure at its proximal end where the strings or filaments converge at a connection point.

Claims

1. An expandable medical implant, comprising:

a mesh structure comprising a first plurality of mesh cells, the mesh structure having a proximal end and a distal end;

a tapering portion comprising a second plurality of mesh cells, the tapering portion disposed toward the proximal end of the mesh structure; and

a connection point, at which the tapering portion converges, located at a proximal end of the tapering portion,

wherein the implant is preformed to assume a volume-enlarged form and, in the volume-enlarged form, takes the form of a longitudinally open tube tapering toward the connection point.

2. The implant according to claim 1, comprising an alloy having shape-memory properties.

3. The implant according to claim 1, wherein the volume-reduced form is a spiral structure.

4. The implant according to claim 1, wherein:

the connection point is centrally arranged in the tapering portion.

5. The implant according to claim 4, further comprising:

a platinum spiral coupled to the connection point.

6. The implant according to claim 1, wherein:

at least one of the tapering portion and the mesh structure is made from one of;

a cut foil curled to form the longitudinally open tube; and

an expanded metal foil curled to form the longitudinally open tube.

7. The implant according to claim 1, wherein:

at least one of the tapering portion and the mesh structure comprises one of;

a plurality of filaments interconnected to one another by welding; and

a mesh braiding of individual filaments.

8. The implant according to claim 7 wherein each filament comprises individual strands worked into a rope-like structure.

9. The implant according to claim 7, further comprising at least one marker disposed at the distal end of the mesh structure.

10. The implant according to claim 9, wherein the at least one marker is arranged at a junction point of at least two filaments.

11. The implant according to claim 7, wherein the mesh braiding comprises a knitted structure that imparts curled up edges to at least one of the tapering portion and the mesh structure.

12. The implant according to claim 11, wherein the knitted structure comprises a fluse-like structure.

13. The implant according to claim 11, wherein edges of the longitudinally open tube are provided so as to overlap one another.

14. The implant according to claim 1, wherein the mesh cells of the first plurality are smaller than the mesh cells of the second plurality.

15. System for the treatment of aneurysms or other vascular malformations for use with a first micro-catheter;

a first guide wire for the placement of the first micro-catheter;

a second guide wire to move through the first micro-catheter and an implant according to claim 1 that is detachably coupled to a distal end of the second guide wire.

16. The system according to claim 15, wherein the implant is detachably coupled to the second guide wire via an electrolytically corrodible element.

17. An implant, comprising:

a first mesh portion comprising a first plurality of mesh cells of a first mesh cell size, the first mesh portion having a distal and a proximal end;

a second mesh portion comprising a second plurality of mesh cells of a second mesh cell size, the second mesh portion having a distal and a proximal end, the second mesh portion coupled to the proximal end of the first mesh portion; and

a single connection point at which the proximal end of the second mesh portion terminates.

18. The implant of claim 17, wherein:

the distal end of the first mesh portion comprises a plurality of free end points,

wherein a free end point defines a closed cell of the first mesh portion.

19. The implant of claim 17, wherein the proximal end of the second mesh portion tapers toward the single connection point.

20. The implant of claim 17, wherein:

each of the first and second mesh portions is impressed with a shape to which the first and second mesh portions will revert unless mechanically restrained.

21. The implant of claim 20, wherein the impressed shape is a longitudinally open tube within a predetermined diameter range.

22. The implant of claim 17, wherein:

the mesh cells of the first mesh portion are smaller than the mesh cells of the second mesh portion.

23. The implant of claim 22, wherein:

the mesh cells of the first mesh portion are substantially smaller, in a latitudinal direction of the implant, than the mesh cells of the second mesh portion.

24. The implant of claim 17, wherein:

at least one of the first and second mesh portions comprises one of;

a plurality of interconnected filaments; and

a mesh braiding of individual filaments.

25. The implant of claim 24, wherein the filaments are interconnected to one another by welding.

26. The implant of claim 17, wherein:

each of a distal and proximal end of the first and second mesh portions comprises a plurality of free end points, each free end point defining a closed cell of the respective mesh portion; and

the distal end points of the second mesh portion are coupled to respective proximal end points of the first mesh portion.

27. The implant of claim 26, further comprising a plurality of additional filaments coupling the second mesh portion to the first mesh portion.

28. The implant of claim 26, further comprising:

at least one filament extending along, and coupled to, corresponding edges of the first and second mesh portions.

29. The implant of claim 17, wherein at least one of the first and second mesh portions comprises a material having shape-memory properties.

30. The implant of claim 29, wherein:

the first and second mesh portions, together, are capable of being rolled up, along a longitudinal axis, into a first curled structure having a first diameter and then progressing to a second curled structure, upon removal of a restricting force, with a second diameter,

wherein the second diameter is larger than the first diameter.

31. The implant of claim 30, further comprising:

first and second edges disposed longitudinally along the first and second mesh portions,

wherein the first and second edges overlap one another when in the first curled structure.

32. A method, comprising:

providing an implant having a first mesh portion comprising a first plurality of mesh cells of a first mesh cell size, the first mesh portion having a distal and a proximal end, a second mesh portion comprising a second plurality of mesh cells of a second mesh cell size, the second mesh portion having a distal and a proximal end, the second mesh portion coupled to the proximal end of the first mesh portion, and a single connection point at which the proximal end of the second mesh portion terminates;

preforming the implant to have a first preformed shape;

curling the implant into a longitudinally-shaped open tube configuration tapering toward the connection point;

maintaining the implant, via a mechanical restraint, in the open tube configuration;

placing the implant in a vessel of a patient;

removing the mechanical restraint; and

leaving the implant positioned in the vessel.

33. The method of claim 32, wherein the first preformed shape is a flat substantially planar form.

34. The method of claim 32, wherein the open tube configuration comprises a spiral shape.