Dual valve, flexible expandable sheath and method

• US 5,935,122 A
• Filed: 08/01/1997
• Issued: 08/10/1999
• Est. Priority Date: 12/13/1991
• Status: Expired due to Term

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: EndoVascular Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Baker, Steven G., Fourkas, Michael G., Mitchell, David H.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): RODRIGUEZ, CRIS LOIREN
• Application Number:
  US08/905,167
• Time in Patent Office: 739 Days
• Field of Search: 604/171, 604/249, 604/256, 604/169, 604/167, 604/164, 604/264, 604/104, 604/280, 604/282, 604/19, 604/165, 604/523, 251/4
• US Class Current: 604/523
• CPC Class Codes: A61B 17/3439 with means for changing the inner diameter of the cannula, e.g. expandable A61B17/3423, A61B17/3431 take precedence; catheters A61M25/0662
• CPC Class Codes: A61B 17/3462 with means for changing the diameter or the orientation of the entrance port of the cannula, e.g. for use with different-sized instruments, reduction ports, adapter seals expandable cannulas A61B17/3417
• CPC Class Codes: A61M 2039/062 used with a catheter
• CPC Class Codes: A61M 2039/0633 the seal being a passive seal made of a resilient material with or without an opening
• CPC Class Codes: A61M 2039/0673 comprising means actively pressing on the device passing through the seal, e.g. inflatable seals, diaphragms, clamps
• CPC Class Codes: A61M 2039/0686 comprising more than one seal
• CPC Class Codes: A61M 25/0021 characterised by the form of the tubing A61M25/0054 takes precedence
• CPC Class Codes: A61M 25/0023 by the form of the lumen, e.g. cross-section, variable diameter
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• 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 25/0075 Valve means
• CPC Class Codes: A61M 25/0662 Guide tubes
• CPC Class Codes: A61M 25/0668 splittable, tear apart
• CPC Class Codes: A61M 39/06 Haemostasis valves, i.e. gaskets sealing around a needle, catheter or the like, closing on removal thereof
• CPC Class Codes: A61M 39/0613 with means for adjusting the seal opening or pressure A61M39/0693 takes precedence

Abstract

A sheath assembly for use in introducing a catheter or other medical instrument into a vessel in the body of a patient. The sheath assembly includes an outer tubular member and an inner tubular member with a conically shaped cap at its distal end. A locking mechanism prevents advancement of the inner tubular member and associated cap in a distal direction of the vessel of the patient independent of the outer tubular member, but allows free movement of the inner tubular member in the proximal direction independent of the outer tubular member.

Claims

1. An introducer sheath assembly comprising:

an elongate sheath tube formed of a flexible material having proximal and distal extremities and having a passage extending therethrough;

an outer tubular member configured coaxially within said sheath tube, and having a proximal extremity that extends beyond said proximal extremity of said sheath tube and a distal extremity configured to pass through said passage of said elongated sheath tube;

an inner tubular member configured coaxially within said outer tubular member and having proximal and distal extremities that extend beyond said extremities of said outer tubular member; and

a cap affixed to said distal extremity of said inner tubular member.

2. The sheath assembly of claim 1, wherein said cap includes a cone with distal and proximal ends, said cone tapered towards said distal end and including an opening formed at said proximal end, said opening providing access to an interior of said cone.

3. The sheath assembly of claim 2, wherein said proximal end is configured to receive said distal end of said flexible sheath in a folded state.

4. The sheath assembly of claim 1, wherein said proximal end of said cap is configured to mate with said distal end of said outer tubular member to provide a smooth tapered transition when said cap abuts against said outer tubular member.

5. An introducer sheath assembly comprising:

an elongate sheath tube formed of a flexible material having proximal and distal extremities and having a passage extending therethrough;

an outer tubular member configured coaxially within said sheath tube and having a proximal extremity that extends beyond said proximal extremity of said elongated sheath tube, and a distal extremity configured to pass through said passage of said elongated sheath tube;

an inner tubular member configured coaxially within said outer tubular member and having proximal and distal extremities that extend beyond said extremities of said outer tubular member; and

a locking mechanism for restricting distal movement of said inner tubular member;

wherein said locking mechanism includes a housing mounted to said proximal end of said outer tubular member, said housing including an inner chamber with an internal distal wall and an internal proximal wall through which said inner tubular member passes.

6. The sheath assembly of claim 5, wherein said proximal wall is oriented substantially perpendicular to said inner tubular member, and said distal wall is oriented at a fixed non-perpendicular angle to said inner tubular member.

7. The sheath assembly of claim 5, wherein said locking mechanism further includes a washer located within said chamber between said distal and proximal walls, said washer having a hole centered therein through which said inner tubular member freely passes when said washer is oriented substantially perpendicular to said inner tubular member.

8. The sheath assembly of claim 7, wherein said washer locks onto said inner tubular member when oriented at an angle which is non-parallel to said inner tubular member.

9. An expandable introducer sheath assembly comprising:

an elongate sheath tube formed of a flexible material having proximal and distal extremities and having a passage extending therethrough;

an outer tubular member configured coaxially within said sheath tube and having a proximal extremity that extends beyond said proximal extremity of said elongated sheath tube, and a distal extremity configured to pass through said passage of said elongated sheath tube;

an inner tubular member configured within said sheath tube and having proximal and distal extremities that extend beyond said extremities of said outer tubular member;

a cap affixed to said distal extremity of said inner tubular member; and

a locking mechanism for restricting distal movement of said inner tubular member, said locking mechanism being structurally connected to said outer tubular member.

10. The sheath assembly of claim 9, wherein said cap includes a cone with distal and proximal ends, said cone tapered towards said distal end and including an opening formed at said proximal end, said proximal end providing access to an interior of said cone.

11. The sheath assembly of claim 10, wherein said proximal end is configured to receive said distal end of said flexible sheath in a folded state.

12. The sheath assembly of claim 10, wherein said proximal end of said cone is configured to mate with said distal end of said outer tubular member to provide a smooth tapered transition when said cap abuts against said outer tubular member.

13. The sheath assembly of claim 9, wherein said locking mechanism includes a housing mounted to said proximal end of said outer tubular member, said housing including an inner chamber with an internal distal wall and an internal proximal wall through which said inner tubular member passes.

14. The sheath assembly of claim 13, wherein said proximal wall is oriented substantially perpendicular to said inner tubular member, and said distal wall is oriented at a fixed non-perpendicular angle to said inner tubular member.

15. The sheath assembly of claim 13, wherein said locking mechanism further comprises a washer located within said chamber, between said distal and proximal walls, said washer having a hole centered therein through which said inner tubular member freely passes when said washer is oriented perpendicular to said inner tubular member.

16. The sheath assembly of claim 13, wherein said washer locks said inner tubular member when oriented at an angle non-parallel to said inner tubular member.