METHOD OF FORMING AN INTRODUCER SHEATH

• US 20100057018A1
• Filed: 08/26/2008
• Published: 03/04/2010
• Est. Priority Date: 08/26/2008
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated)
• Inventors: Lentz, David Christian, Howat, William L.
• Granted Patent: US 7,815,762 B2
• Time in Patent Office: Days
• US Class Current: 604/264
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0026 Multi-lumen catheters with stationary elements catheter assemblies comprising a catheter in combination with a guide tube, sheath or sleeve A61M2025/0681; catheters comprising telescoping coaxial elements A61M2025/0175
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• CPC Class Codes: A61M 25/0662 Guide tubes
• CPC Class Codes: B29C 57/00 Shaping of tube ends, e.g. flanging, belling or closing; Apparatus therefor , e.g. collapsible mandrels
• CPC Class Codes: B29C 61/025 for the production of hollow or tubular articles
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/66 by liberation of internal stresses, e.g. shrinking of one of the parts to be joined
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/545 one hollow-preform being placed inside the other
• CPC Class Codes: B29C 66/63 Internally supporting the article during joining B29C66/49 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73115 Melting point
• CPC Class Codes: B29C 66/73116 of different melting point, i.e. the melting point of one of the parts to be joined being different from the melting point of the other part
• CPC Class Codes: B29C 66/7371 oriented or heat-shrinkable
• CPC Class Codes: B29C 66/73715 heat-shrinkable
• CPC Class Codes: B29C 66/7392 characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/964 involving trial and error
• CPC Class Codes: B29C 70/70 Completely encapsulating inserts B29C70/86 takes precedence
• CPC Class Codes: B29C 70/82 Forcing wires, nets or the like partially or completely into the surface of an article, e.g. by cutting and pressing
• CPC Class Codes: B29D 23/001 : Pipes; Pipe joints pleated hoses B29D23/18
• CPC Class Codes: B29K 2027/18 : PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2075/00 : Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0827 : Braided fabrics
• CPC Class Codes: B29L 2023/005 : Hoses, i.e. flexible
• CPC Class Codes: B29L 2031/24 : Pipe joints or couplings B29L2031/26 takes precedence
• CPC Class Codes: F16L 11/081 : comprising one or more layers of a helically wound cord or wire in combination with braided layers F16L11/088
• CPC Class Codes: Y10T 156/1005 : by inward collapsing of portion of hollow body
• CPC Class Codes: Y10T 156/1033 : Flexible sheet to cylinder lamina

Abstract

A method of forming an introducer sheath having a crease-free tapered distal tip portion. A mandrel is provided having an outer configuration comprising an elongated body and a tapered distal tip portion. A generally tubular inner liner comprising heat shrinkable PTFE, is positioned over the mandrel. The inner liner is heat shrunk to the outer configuration of the mandrel, in a manner that avoids the formation of creases along the inner diameter of the liner. A reinforcing member is positioned over a length of the inner liner, and an outer jacket is positioned over the reinforcing member and the inner liner. The liner, reinforcing member, and outer jacket are heated in a heat shrink enclosure, whereby the outer jacket melts and bonds to an outer surface of the inner liner.

Claims

1. A method of forming an introducer sheath having a tapered distal tip portion, comprising:

providing a mandrel having an outer configuration comprising an elongated body and a tapered distal tip;

positioning a generally tubular inner liner over the mandrel, said inner liner comprising a heat shrinkable fluoropolymer;

heat shrinking the inner liner over the mandrel such that said inner liner shrinks to the outer configuration of the mandrel, a distal portion of the inner liner shrinking to the configuration of the mandrel tapered distal tip and having an inner diameter substantially free of creases therealong;

positioning a reinforcing member over a length of the inner liner;

positioning an outer jacket over the reinforcing member and the inner liner; and

heating an assembly comprising said inner liner, reinforcing member, and outer jacket, such that said outer jacket bonds to an outer surface of said inner liner.

2. The method of claim 1, wherein said fluoropolymer comprises heat shrinkable polytetrafluoroethylene (PTFE).

3. The method of claim 2, wherein said PTFE inner liner is heat shrunk over said mandrel at a temperature of about 650°

F. (340°

C.).

4. The method of claim 2, wherein said reinforcing member comprises a coil having a plurality of coil turns, and wherein said outer jacket bonds to said inner liner through said coil turns.

5. The method of claim 4, wherein said assembly is heated in a heat shrink enclosure.

6. The method of claim 5, wherein said enclosure comprises fluorinated ethylene propylene (FEP).

7. The method of claim 4, wherein said outer jacket comprises a thermoplastic material selected from the group consisting of polyether block amide, nylon, and polyurethane.

8. The method of claim 4, wherein said outer jacket comprises a plurality of jacket segments, said segments aligned in order of decreasing durometer from a proximal end to a distal end of said outer jacket.

9. A method of forming an introducer sheath, comprising:

providing a mandrel comprising an elongated body and a tapered distal tip portion;

heat shrinking a polymeric tubular liner to the outer configuration of the mandrel, said liner having a first melt temperature; and

heat shrinking an outer jacket over the liner such that the outer jacket bonds to an outer surface of the liner, said outer jacket having a second melt temperature, the second melt temperature being less than the first melt temperature.

10. The method of claim 9, wherein said polymeric tubular liner comprises heat shrinkable polytetrafluoroethylene (PTFE).

11. The method of claim 10, wherein said first melt temperature is about 650°

F. (340°

C.).

12. The method of claim 10, further comprising the step of positioning a reinforcing member over the polymeric tubular liner prior to heat shrinking the outer jacket.

13. The method of claim 12, wherein said reinforcing member comprises a coil having a plurality of coil turns, and said outer jacket is bonded to said liner outer surface through said coil turns.

14. The method of claim 10, wherein said outer jacket comprises a polyether block amide, nylon or polyurethane.

15. The method of claim 12, wherein said outer jacket is heat shrunk over the mandrel by placing the mandrel, liner, reinforcing member, and outer jacket in a heat shrink enclosure formed of FEP, and wherein said second melt temperature is about 365°

F. (185°

C.).

16. An introducer sheath, comprising:

an inner liner having a proximal end and a distal end, said inner liner having an inner diameter and an outer diameter, said inner and outer diameters tapering to a distal tip portion of said inner liner, said inner diameter taper being free of creases therealong;

a reinforcing member positioned over said inner liner; and

an outer jacket having a proximal end and a distal end, said outer jacket having an inner diameter and an outer diameter, said inner and outer diameters tapering to a distal tip portion of said outer jacket, said outer jacket positioned longitudinally around said reinforcing member and said inner liner, and bonded to said outer diameter of said inner liner.

17. The introducer sheath of claim 16, wherein said inner liner comprises heat shrinkable PTFE.

18. The introducer sheath of claim 17, wherein said reinforcing member comprises at least one of a coil and a braid.

19. The introducer sheath of claim 18, wherein said outer jacket comprises a polyether block amide, nylon, or polyurethane.

20. The introducer sheath of claim 16, wherein said inner liner having said crease-free inner diameter comprises PTFE, said reinforcing member comprises a helical coil with a plurality of substantially equally spaced coil turns, and said outer jacket is bonded to said inner liner through said coil turns, said outer jacket proximal end having a higher durometer than said outer jacket distal end.