EXPANDABLE CANNULA

• US 20080051734A1
• Filed: 10/31/2007
• Published: 02/28/2008
• Est. Priority Date: 02/04/1993
• Status: Abandoned Application

• Current Assignee: Bonutti Skeletal Innovations LLC (Acacia Research Corporation)
• Original Assignee: Bonutti Skeletal Innovations LLC (Acacia Research Corporation)
• Inventors: Hawkins, James, Bonutti, Peter
• Application Number:
  US11/930,332
• Publication Number:
  US 20080051734A1
• Time in Patent Office: Days
• US Class Current: 604/264
• CPC Class Codes: A61B 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• 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 2017/0409 Instruments for applying suture anchors
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening
• CPC Class Codes: A61B 2017/0417 T-fasteners
• CPC Class Codes: A61B 2017/06052 Needle-suture combinations in which a suture is extending inside a hollow tubular needle, e.g. over the entire length of the needle
• CPC Class Codes: A61B 2017/3486 Balloon
• CPC Class Codes: A61M 2025/0024 Expandable catheters or sheaths
• CPC Class Codes: A61M 2025/0089 Single injection needle protruding axially, i.e. along the longitudinal axis of the catheter, from the distal tip
• CPC Class Codes: A61M 2025/0095 being one or more needles protruding from the distal tip and which are not used for injection nor for electro-stimulation, e.g. for fixation purposes
• CPC Class Codes: A61M 25/0084 being one or more injection needles
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence
• CPC Class Codes: A61M 25/06 Body-piercing guide needles or the like
• CPC Class Codes: A61M 25/0662 Guide tubes

Abstract

Cannulas for surgical and medical use expand along their lengths. The cannulas are inserted through tissue when in an unexpanded condition and with a small diameter. The cannulas are then expanded radially outwardly to give a full-size instrument passage. Expansion of the cannulas occurs against the viscoelastic resistance of the surrounding tissue. The expandable cannulas do not require a full depth incision, or at most require only a needle-size entrance opening. In one embodiment of the invention, the cannula includes a number of arcuate plate segments movable with respect to each other for enabling an increase in cross-sectional area of the cannula lumen. In this embodiment, the cannula can be provided with a pointed end portion. The cannula may be expanded by inserting members or by fluid pressure. The cannula is advantageously utilized to expand a vessel, such as a blood vessel. An expandable chamber may be provided at the distal end of the cannula.

Claims

1. A method of accessing an interior portion of a body of a patient, comprising

inserting an expandable cannula into the body of the patient, the expandable cannula including a tubular sheath defining a passage extending between axially opposite end portions of the tubular sheath;

expanding the tubular sheath and passage from a first position having a first cross sectional area to a second position having a second cross sectional area, wherein the second cross sectional area is greater than the first cross sectional area; and

inserting a medical device through the passage into the interior portion of the body of the patient.

2. The method of claim 1, wherein inserting an expandable cannula into the body of the patient comprises:

piercing the body of the patient with a distal end of the tubular sheath; and

inserting at least a portion of the tubular sheath through the piercing.

3. The method of claim 2, wherein piercing the body of the patient with a distal end of the tubular sheath comprises:

inserting a trocar through the passage such that a sharpened tip of the trocar extends past the distal end of the tubular sheath; and

piercing the body of the patient with the sharpened tip of the trocar; and

removing the trocar from the expandable cannula.

4. The method of claim 2, wherein the distal end portion of the tubular sheath comprises a pointed end portion when the tubular sheath is in the first position.

5. The method of claim 1, wherein inserting an expandable cannula into the body of the patient comprises:

making an incision in the body of the patient; and

inserting at least a portion of the tubular sheath through the incision.

6. The method of claim 1, wherein the first cross sectional area is a first oval cross sectional area.

7. The method of claim 1, wherein the second cross sectional area is a second oval cross sectional area.

8. The method of claim 1, wherein expanding the tubular sheath and passage from a first position having a first cross sectional area to a second position having a second cross sectional area, comprises:

inserting a first longitudinal expansion member into the passage, the first longitudinal expansion member having a cross sectional area greater than the first cross sectional area, such that the passage expands from the first cross sectional area to the second cross sectional area.

9. The method of claim 1, further comprising expanding the tubular sheath and passage from the second position to a third position having a third cross sectional area, wherein the third cross sectional area is greater than the second cross sectional area.

10. The method of claim 9, wherein expanding the tubular sheath and passage from a first position having a first cross sectional area to a second position having a second cross sectional area, comprises inserting a first longitudinal expansion member into the passage, the first longitudinal expansion member having a cross sectional area greater than the first cross sectional area, such that the passage expands from the first cross sectional area to the second cross sectional area.

11. The method of claim 10, wherein expanding the tubular sheath and passage from the second position to a third position having a third cross sectional area, comprises:

inserting a second longitudinal expansion member into the passage, the second longitudinal expansion member having a third cross sectional area greater than the second cross sectional area, such that the passage expands from the second cross sectional area to the third cross sectional area; and

removing the first longitudinal expansion member.

12. The method of claim 11, wherein removing the first longitudinal expansion member comprises:

removing the first longitudinal expansion member prior to inserting the second longitudinal expansion member, such that the passage radially contracts.

13. The method of claim 12, further comprising allowing tissue surrounding the tubular sheath to relax prior to removing the first longitudinal expansion member.

14. The method of claim 1, further comprising removing the tubular sheath.

15. The method of claim 1, wherein the tubular sheath is resiliently expandable.

16. The method of claim 1, wherein the medical device has a cross sectional area greater than the first cross sectional area of the passage in the first position.

17. A method of accessing an interior portion of a body of a patient, comprising:

piercing the body of the patient with a distal end portion of an expandable cannula, the expandable cannula including a tubular sheath defining a passage extending between a proximal end portion and the distal end portion of the tubular sheath;

inserting at least a portion of the tubular sheath through the piercing; and

expanding the tubular sheath and passage from a first position having a first cross sectional area to a second position having a second cross sectional area greater than the first cross sectional area, wherein the distal end portion of the tubular sheath includes a pointed end portion when the tubular sheath in is the first position.

18. A method of accessing an interior portion of a body of a patient, comprising:

inserting an expandable cannula into the body of the patient, the expandable cannula including a tubular sheath defining a passage extending between axially opposite end portions of the tubular sheath; and

expanding the tubular sheath and passage from a first position having a first oval cross sectional area to a second position having a second oval cross sectional area, wherein the second oval cross sectional area is greater than the first oval cross sectional area.