Electrode screen enhanced electrosurgical apparatus and methods for ablating tissue

• US 7,241,293 B2
• Filed: 11/13/2003
• Issued: 07/10/2007
• Est. Priority Date: 11/20/1998
• Status: Expired due to Fees

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Davison, Terry S.
• Primary Examiner(s): Cohen; Lee S.
• Application Number:
  US10/713,643
• Publication Number:
  US 20040153057A1
• Time in Patent Office: 1,335 Days
• Field of Search: 606/41, 606/45, 606/46, 606 48- 50, 607/99, 607/105, 607/113, 604/35, 604/114
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 18/149 bow shaped or with rotatable body at cantilever end, e.g. for resectoscopes, or coagulating rollers
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00101 using an array of thermosensors
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00119 with metal oxide nitride
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00178 Electrical connectors
• CPC Class Codes: A61B 2018/00291 using suction
• CPC Class Codes: A61B 2018/00327 Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00505 Urinary tract
• CPC Class Codes: A61B 2018/00577 : Ablation
• CPC Class Codes: A61B 2018/00583 : Coblation, i.e. ablation using a cold plasma
• CPC Class Codes: A61B 2018/00601 : Cutting
• CPC Class Codes: A61B 2018/00666 : using a threshold value
• CPC Class Codes: A61B 2018/00678 : upper
• CPC Class Codes: A61B 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/0072 : Current
• CPC Class Codes: A61B 2018/00726 : Duty cycle
• CPC Class Codes: A61B 2018/00779 : Power or energy
• CPC Class Codes: A61B 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00827 : Current
• CPC Class Codes: A61B 2018/00875 : Resistance or impedance
• CPC Class Codes: A61B 2018/00982 : combined with or comprising means for visual or photographic inspections inside the body, e.g. endoscopes
• CPC Class Codes: A61B 2018/1213 : creating an arc
• CPC Class Codes: A61B 2018/124 : switching the output to different electrodes, e.g. sequentially
• CPC Class Codes: A61B 2018/1253 : monopolar
• CPC Class Codes: A61B 2018/126 : bipolar
• CPC Class Codes: A61B 2018/1273 : including multiple generators in one device
• CPC Class Codes: A61B 2018/1407 : Loop
• CPC Class Codes: A61B 2018/1467 : using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1472 : for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2018/162 : located on the probe body
• CPC Class Codes: A61B 2018/165 : Multiple indifferent electrodes
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration

Abstract

Electrosurgical methods and apparatus for the controlled ablation of tissue from a target site of a patient. The instrument includes a shaft having proximal and distal end portion and an active screen electrode on the distal end portion; a return electrode arranged on the shaft spaced from the screen electrode; at least one electrical connector extending through the shaft that connects the active electrode with a high frequency power supply; at least one electrical coupling member (such as a ball wire) adapted to secure the active screen electrode to the shaft and to electrically couple the screen electrode to the at least one electrical connector; and an aspiration lumen within the shaft having a distal opening coupled to the single active electrode wherein the screen electrode inhibits clogging of the aspiration lumen.

Claims

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

(a) a shaft having a proximal end portion and a distal end portion, and an active electrode comprising a substantially flat active screen electrode disposed on the distal end portion of the shaft;

(b) a return electrode arranged on the shaft, and spaced from the active screen electrode;

(c) at least one electrical connector extending through the shaft and having an end that is proximal to the flat screen;

(d) at least one electrical coupling member adapted to secure the active screen electrode to the shaft and to electrically couple the active screen electrode to said at least one electrical connector; and

(e) an aspiration lumen disposed within the shaft and having a distal opening coupled to the active screen electrode wherein the active screen electrode inhibits clogging of the aspiration lumen.

2. The instrument of claim 1 wherein the active screen electrode comprises at least one aperture for passage of tissue fragments and fluid therethrough.

3. The instrument of claim 2 wherein said at least one aperture comprises a plurality of apertures.

4. The instrument of claim 3 wherein said apertures are circular.

5. The instrument of claim 3 wherein said apertures comprise corners.

6. The instrument of claim 5 wherein said apertures are rectangular.

7. The instrument of claim 1 wherein the active screen electrode is disposed on a lateral side of the shaft.

8. The instrument of claim 1 further comprising an electrically insulating support member upon which the active screen electrode is mounted.

9. The instrument of claim 8 wherein the support member defines an axial opening in communication with the aspiration lumen, and a lateral opening in contact with the active screen electrode.

10. The instrument of claim 8 further comprising a cap arranged on the distal end portion of the shaft wherein said cap comprises an opening that receives said insulating support member.

11. The instrument of claim 10 wherein said cap is adhered to the return electrode.

12. The instrument of claim 1 wherein the return electrode is comprised of an annular member.

13. The instrument of claim 1 wherein the return electrode is spaced from the active screen electrode such that, when the active screen electrode is brought adjacent to a tissue structure immersed in an electrically conductive fluid, the active screen electrode is positioned between the return electrode and the tissue structure, and the electrically conductive fluid completes a conduction path between the active screen electrode and the return electrode.

14. The instrument of claim 13 wherein the active and return electrodes are configured, upon the application of a sufficiently high frequency voltage therebetween, to vaporize the conductive fluid in a thin layer over at least a portion of the active electrode, and to induce the discharge of energy from the vapor layer.

15. The instrument of claim 1 wherein said at least one electrical coupling member comprises a ballwire.

16. The instrument of claim 1 wherein said at least one electrical coupling member comprises a plurality of electrical coupling members.

17. The instrument of claim 1 wherein the return electrode is arranged on said distal end portion and is ring shaped.

18. The instrument of claim 1 further comprising a liquid supply lumen adapted to supply liquid to the distal end portion of the shaft.

19. A method for treating target tissue whereby a portion of the target tissue is removed, comprising the steps of:

advancing a probe comprising a proximal end, a shaft, a distal end portion, and a substantially flat active screen electrode secured on the distal end portion of the probe such that the active electrode is positioned in close proximity to the target tissue, said probe further comprising at least one electrical connector extending through said shaft and terminating proximal to said screen electrode, and wherein said screen electrode is electrically coupled and mechanically affixed to said probe by a coupling agent;

delivering to the target tissue an electrically conductive fluid;

applying suction to an aspiration lumen disposed within the probe to remove ablated material from the target site, the aspiration lumen being in fluid communication with openings in the screen of the active electrode; and

applying a high frequency voltage between the active electrode and a return electrode to ablate tissue at the target site,

whereby the screen electrode inhibits clogging of the aspiration lumen.

20. The method of claim 19 wherein said target tissue is within a joint.

21. The method of claim 20 wherein said tissue is selected from the group consisting of meniscus, synovial tissue, and articular cartilage.

22. The method of claim 19 wherein said aspiration lumen is connected with a vacuum source to aspirate material through said aspiration lumen.

23. The method of claim 19 wherein said tissue is a tissue selected from the group consisting of the tonsils and adenoids.

24. The method of claim 19 wherein said screen is attached to said distal end without a press-fit.

25. A method for treating target tissue whereby a portion of the target tissue is removed, comprising the steps of:

advancing a probe comprising a proximal end, a shaft, a distal end portion, and a substantially flat active screen electrode secured on the distal end portion of the probe such that the active electrode is positioned in close proximity to the target tissue, said probe further comprising at least one electrical connector extending through said shaft and coupled to said screen electrode, and wherein said screen electrode is electrically coupled and mechanically affixed to said probe without a press-fit;

delivering to the target tissue an electrically conductive fluid;

applying suction to an aspiration lumen disposed within the probe to remove ablated material from the target site, the aspiration lumen being in fluid communication with openings in the screen of the active electrode; and

applying a high frequency voltage between the active electrode and a return electrode to ablate tissue at the target site,

whereby the screen electrode inhibits clogging of the aspiration lumen.