System, method and apparatus for electrosurgical instrument with movable suction sheath

• US 8,317,786 B2
• Filed: 09/25/2009
• Issued: 11/27/2012
• Est. Priority Date: 09/25/2009
• Status: Active Grant

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Dahla, Robert H., Gutierrez, Irma
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): DELLA, JAYMI E
• Application Number:
  US12/566,913
• Publication Number:
  US 20110077643A1
• Time in Patent Office: 1,159 Days
• Field of Search: 606/48, 606/50, 604/27, 604/33, 604/35, 604/158, 604/163, 604/164.02, 604/181, 604/183, 604/30, 604/40, 604118-121, 604/508, 251/237
• US Class Current: 606/48
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 2018/00583 Coblation, i.e. ablation using a cold plasma
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/007 Aspiration

Abstract

An electrosurgical instrument having active and return electrodes with a movable suction sheath for variable fluid and debris removal during surgical procedures is disclosed. The suction apparatus has an outer sheath that is external to a shaft to provide a lumen. The sheath assembly is axially movable relative to the fluid aspiration element between first and second positions for treating the target site and fluid and debris removal, respectively. The first position positions the distal end of the shaft axially distal to a leading edge of the sheath assembly. The second position positions the distal leading edge of the sheath assembly axially adjacent to the end of the shaft. The fluid aspiration element comprises an inner lumen extending through the shaft, and at least one port extending radially through the shaft. The port is in communication with the inner lumen. A vacuum provides suction through the port and inner lumen.

Claims

1. A system for treating tissue, comprising:

an electrosurgical instrument having a shaft with a proximal end and a distal end;

an electrode assembly comprising at least one active electrode positioned on the distal end of the shaft and a return electrode positioned on the shaft and axially spaced from the at least one active electrode;

an aspiration element for aspirating fluid and debris from a target site, the aspiration element comprising an inner lumen extending through a portion of the shaft, first and second ports extending radially through the shaft in fluid communication with the inner lumen, wherein the first and second ports are axially spaced apart; and

a sheath assembly disposed adjacent to the aspiration element, the sheath assembly defining an annular space around the shaft and being axially movable relative to the aspiration element between a first position and a second position, wherein at least one radial seal is disposed within the annular space;

wherein the sheath assembly in the second position disposes the radial seal adjacent the second port and the sheath assembly in the first position spaces the radial seal proximally from the second port.

2. A system according to claim 1, wherein a distal leading edge of the sheath assembly is disposed axially proximal to the distal end of the shaft in the first position, and the distal leading edge of the sheath assembly is disposed substantially axially adjacent to the distal end of the shaft in the second position.

3. A system according to claim 1, further comprising a vacuum source connected to the inner lumen for providing suction through the first and second ports and inner lumen.

4. A system according to claim 1, wherein the first and second ports each comprise a plurality of ports that are located adjacent the distal end of the shaft and axially spaced from the electrode assembly.

5. A system according to claim 1 wherein the sheath assembly comprises an elongate tube that is slidably movable relative to and concentric with the shaft, the tube having a distal terminus moveable so as to be disposed adjacent the electrosurgical instrument distal end and wherein the tube defines an outer lumen for annular fluid flow between the elongate tube and the shaft, the radial seal being disposed between an outer surface of the shaft and an inner surface of the tube and sealingly engaging the shaft and the tube.

6. A system according to claim 5, wherein the radial seal comprises a plurality of o-rings that are seated in an axial series of radial grooves formed in the inner surface of the tube, the radial grooves being axially spaced from each other.

7. A system according to claim 1, wherein the first position is operable to aspirate at a distance spaced away from the active electrode and the second position is operable to aspirate adjacent to the active electrode.

8. A system according to claim 1, wherein the sheath assembly has a range of motion between the first and second positions that provides a variable level of fluid and debris removal, from a minimal level of fluid and debris removal in the first position, to a maximum level of fluid and debris removal in the second position.

9. A system for treating tissue, comprising:

an electrosurgical instrument having a shaft with a proximal end and a distal end;

an electrode assembly comprising at least one active electrode positioned on the distal end of the shaft and a return electrode positioned on the shaft and axially spaced from the at least one active electrode;

an aspiration element for aspirating fluid and debris from a target site comprising an inner lumen extending through a portion of the shaft, and first and second ports extending radially through the shaft in fluid communication with the inner lumen, the first and second ports axially spaced apart;

a sheath assembly disposed adjacent to the aspiration element, the sheath assembly defining an annular space around the shaft and being axially movable relative to the aspiration element between a first position and a second position;

wherein the sheath assembly comprises a tube that is slidably movable relative to and concentric with the shaft, the tube defining an outer lumen between the tube and the shaft and having at least one radial seal, the at least one radial seal being disposed in the outer lumen between an outer surface of the shaft and an inner surface of the tube and sealingly engaging the shaft and the tube;

and further comprising;

a vacuum source connected to the inner lumen; and

the vacuum source connected to the outer lumen proximal to the radial seal and, when the sheath assembly is in the second position, the vacuum source provides a sequential suction path through the inner lumen via a distal opening disposed at the distal end of the shaft, the outer lumen that is distal to the radial seal, the first port, the second port, and the outer lumen proximal to the radial seal.

10. A system according to claim 9, wherein the first and second ports each comprise a plurality of ports, with the first ports being located adjacent the distal end of the shaft and axially spaced from the electrode assembly, and the second ports being located proximal to the first ports.

11. An electrosurgical instrument for removing tissue from a target site within or on a patient'"'"'s body comprising:

a shaft having proximal and distal end portions;

an electrode assembly comprising at least one active electrode positioned on the distal end portion of the shaft and a return electrode positioned on the shaft and axially spaced from the at least one active electrode;

an aspiration element for aspirating fluid and debris from the target site, the aspiration element coupled to a vacuum system, wherein the aspiration element comprises an inner lumen disposed in the shaft and a plurality of ports extending radially through the shaft and axially spaced from one another, the plurality of ports in fluid communication with the inner lumen; and

a movable sheath assembly disposed adjacent to the shaft and defining an annular space around the shaft, the sheath assembly comprising an elongate tube with a distal end portion movable from a first position wherein the distal end portion is retracted proximally from the electrode assembly to a second position wherein the distal end portion is adjacent to the electrode assembly;

wherein the elongate tube defines an outer lumen between the elongate tube and the shaft and wherein at least one radial seal is disposed between an outer surface of the shaft and an inner surface of the elongate tube to sealingly engage the shaft and the elongate tube.

12. The electrosurgical instrument of claim 11, the inner lumen having a distal opening.

13. An electrosurgical instrument for removing tissue from a target site within or on a patient'"'"'s body comprising:

a shaft having proximal and distal end portions;

an electrode assembly comprising at least one active electrode positioned on the distal end port of the shaft and a return electrode positioned on the shaft and axially spaced from the at least one active electrode;

an aspiration element for aspirating fluid and debris from the target site, the aspiration element coupled to a vacuum system;

a movable sheath assembly disposed adjacent to the shaft and defining an annular space around the shaft, the sheath assembly having a distal end portion and being movable from a first position wherein the distal end portion is retracted proximally from the electrode assembly to a second position wherein the distal end portion is adjacent to the electrode assembly; and

wherein the sheath assembly comprises a tube that is slidably movable relative to and concentric with the shaft, the tube defining an outer lumen between the tube and the shaft and having at least one radial seal, the at least one radial seal being disposed between an outer surface of the shaft and an inner surface of the tube and sealingly engaging the shaft and the tube;

wherein the aspiration element comprises an inner lumen disposed in the shaft and a first and second plurality of ports extending radially through the shaft and axially spaced away from each other, the plurality of ports in fluid communication with the inner lumen and the annular space; and

wherein the first and second plurality of ports are fluidly bypassed in the first position, and wherein the first and second plurality of ports are fluidly connected to the outer lumen proximal the at least one radial seal in the second position.