System for treating articular cartilage defects

• US 7,201,750 B1
• Filed: 05/18/1999
• Issued: 04/10/2007
• Est. Priority Date: 01/07/1992
• Status: Expired due to Fees

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Eggers, Philip E., Thapliyal, Hira V.
• Primary Examiner(s): Cohen; Lee S.
• Application Number:
  US09/314,247
• Time in Patent Office: 2,884 Days
• Field of Search: 606/32, 606/41, 606/49, 606/50, 606/46, 607/98, 607/99, 607/101, 607/105, 607/113, 604/114
• US Class Current: 606/41
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• 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 2017/00097 one of the thermometric elements being an electrode or the heating element
• CPC Class Codes: A61B 2017/00101 using an array of thermosensors
• CPC Class Codes: A61B 2017/00106 ultrasonic
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22038 with a guide wire
• 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 2018/00196 : reciprocating lengthwise
• CPC Class Codes: A61B 2018/00327 : Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/0047 : Upper parts of the skin, e.g. skin peeling or treatment of wrinkles
• CPC Class Codes: A61B 2018/00476 : Hair follicles
• 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 2018/00642 : with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/0066 : without feedback, i.e. open loop control
• CPC Class Codes: A61B 2018/00678 : upper
• CPC Class Codes: A61B 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/00726 : Duty cycle
• CPC Class Codes: A61B 2018/00738 : Depth, e.g. depth of ablation
• CPC Class Codes: A61B 2018/00755 : Resistance or impedance
• CPC Class Codes: A61B 2018/00761 : Duration
• CPC Class Codes: A61B 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00797 : measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00821 : measured by a thermocouple
• CPC Class Codes: A61B 2018/00827 : Current
• CPC Class Codes: A61B 2018/00875 : Resistance or impedance
• CPC Class Codes: A61B 2018/00886 : Duration
• 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 2018/1246 : characterised by the output polarity
• 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 2090/378 : using ultrasound
• CPC Class Codes: A61B 2090/3782 : transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration
• CPC Class Codes: A61F 2/2493 : Transmyocardial revascularisation [TMR] devices
• CPC Class Codes: A61F 2/95 : Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61M 25/0133 : Tip steering devices
• CPC Class Codes: A61M 25/0147 : with movable mechanical means, e.g. pull wires
• CPC Class Codes: A61M 25/0158 : with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials

Abstract

An electrosurgical probe (10) comprises a shaft (13) having an electrode array (58) at its distal end and a connector (19) at its proximal end for coupling the electrode array to a high frequency power supply (28). The shaft includes a return electrode (56) recessed from its distal end and enclosed within an insulating jacket (18). The return electrode defines an inner passage (83) electrically connected to both the return electrode and the electrode array for passage of an electrically conducting liquid (50). By applying high frequency voltage to the electrode array and the return electrode, the electrically conducting liquid generates a current flow path between the return electrode and the electrode array so that target tissue may be cut or ablated. The probe is particularly useful in dry environments, such as the mouth or abdominal cavity, because the electrically conducting liquid provides the necessary return current path between the active and return electrodes.

Claims

1. An electrosurgical system for smoothing body structures having an irregular surface:

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

an electrode terminal disposed at or near the distal end of the shaft;

an electrically insulating support member at or near the distal end of the instrument shaft, wherein the electrode terminal is flush with a tissue treatment surface of the support member;

a return electrode spaced from the electrode terminal such that when a portion of the electrode terminal is brought adjacent the irregular surface of the body structure immersed in electrically conductive fluid, the electrode terminal is positioned between the return electrode and the body structure and the electrically conductive fluid completes a conduction path between the electrode terminal and the return electrode;

at least one connector disposed near the proximal end of the shaft for electrically coupling the electrode terminal and the return electrode to a high frequency voltage source; and

wherein the electrode terminal is sized and constructed to deliver sufficient energy to an irregular surface of a body structure to at least partially smooth the irregular surface of the body structure.

2. The system of claim 1 wherein the electrode terminal is configured to deliver sufficient energy to smooth the irregular surface of the articular cartilage while minimizing the depth of ablation and necrosis in the articular cartilage.

3. The system of claim 1 wherein the electrode terminal comprises a tissue treatment surface and a second surface opposite the tissue treatment surface and spaced from the tissue treatment surface in a tissue treatment direction, and wherein the return electrode is spaced about 0.5 to 25 mm in the tissue treatment direction from the second opposite surface of the electrode terminal.

4. The system of claim 1 wherein the return electrode is positioned on the shaft proximal to the electrode terminal.

5. The system of claim 1 wherein the electrode terminal is configured to deliver sufficient energy to ablate at least a portion of cartilage strands on the irregular surface of the articular cartilage to smooth said surface.

6. The system of claim 1 wherein the electrode terminal is configured to deliver sufficient energy to heat at least a portion of cartilage strands on the irregular surface of the articular cartilage to smooth said surface.

7. The system of claim 1 wherein the electrode terminal comprises a single electrode disposed near the distal end of the instrument shaft.

8. The system of claim 1 wherein the electrode terminal includes an array of electrically isolated electrode terminals disposed near the distal end of the instrument shaft.

9. The system of claim 1 further comprising a fluid delivery element for delivering electrically conductive fluid to the electrode terminal.

10. The system of claim 1 further comprising a fluid delivery element, wherein the fluid delivery element comprises a fluid lumen on the instrument shaft.

11. The system of claim 1 further comprising a high frequency voltage source coupled to the electrode terminal and the return electrode, the voltage source having an operating voltage between about 10 volts RMS and 1000 volts RMS.

12. The system of claim 1 wherein the electrode terminal is disposed over a lateral surface of the electrically insulating support member near the distal end of the instrument shaft.

13. The system of claim 1 wherein the the electrode terminal comprises a distal surface having a shape selected from the group consisting essentially of flat, concave, convex, hemispherical, pyramidal, conical and cylindrical.

14. The system of claim 1 further comprising a temperature sensor adjacent to the electrode terminal for controlling power delivery to the electrode terminal based on temperature at a target site.

15. The system of claim 1 further comprising a fluid source for supplying the electrically conductive fluid, wherein the electrically conductive fluid has originated from the fluid source, and the fluid source is an external source outside of a patient'"'"'s body.

16. The system of claim 15 wherein the electrically conductive fluid comprises isotonic saline.

17. An electrosurgical system for smoothing body structures having an irregular surface, comprising:

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

an active electrode disposed at the distal end portion of the shaft and having a tissue treatment surface;

an electrically insulating support member at or near the distal end portion of the shaft, wherein the tissue treatment surface of the active electrode is flush with a tissue treatment surface of the support member;

a return electrode;

a high frequency power source;

at least one connector disposed near the proximal end portion of the shaft electrically coupling the active and return electrodes to the high frequency power source; and

a fluid delivery element for delivering electrically conductive fluid between the active electrode and the body structure.

18. The system of claim 17 wherein the return electrode is positioned on the instrument and axially spaced from the active electrode.

19. The system of claim 17 further comprising a temperature sensor on the distal end portion of the instrument.

20. The system of claim 19 further comprising a temperature controller coupled to the temperature sensor and the high frequency power source for regulating the power applied to the electrode terminal based on the temperature at a target site.

21. The system of claim 20 wherein the temperature controller adjusts the output voltage of the high frequency power source in response to a temperature set point and the measured temperature value received from the temperature sensor.

22. The system of claim 20 wherein the temperature controller limits or interrupts current flow to the active electrode when the temperature of the temperature sensor reaches a threshold value.

23. An electrosurgical system for smoothing body structures having an irregular surface, comprising:

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

an electrode terminal disposed at or near the distal end of the shaft;

a return electrode;

an electrically insulating support member at or near the distal end of the shaft, wherein the electrode terminal is flush with a tissue treatment surface of the support member;

at least one connector disposed near the proximal end of the shaft for electrically coupling the electrode terminal and the return electrode to a high frequency voltage source; and

a temperature sensor adjacent to the electrode terminal, the temperature sensor adapted for being electrically coupled to the high frequency voltage source for controlling power delivery to the electrode terminal based on temperature at a target site;

wherein the electrode terminal is sized and constructed to deliver sufficient energy to an irregular surface of a body structure to at least partially smooth the irregular surface of the body structure.

24. The system of claim 23 wherein the electrode terminal is configured to deliver sufficient energy to smooth the irregular surface of an articular cartilage while minimizing the depth of ablation and necrosis in the articular cartilage.

25. The system of claim 23 wherein the return electrode is spaced from the electrode terminal such that when a portion of the electrode terminal is brought adjacent to the irregular surface of the body structure immersed in electrically conductive fluid, the electrode terminal is positioned between the return electrode and the body structure and the electrically conductive fluid completes a conduction path between the electrode terminal and the return electrode.

26. The system of claim 25 further comprising a fluid source for supplying the electrically conductive fluid, wherein the electrically conductive fluid has originated from the fluid source, and the fluid source is an external source outside of a patient'"'"'s body.

27. The system of claim 26 wherein the electrically conductive fluid comprises isotonic saline.

28. The system of claim 23 wherein the electrode terminal comprises a tissue treatment surface and a second surface opposite the tissue treatment surface and spaced from the tissue treatment surface in a tissue treatment direction, and wherein the return electrode is spaced about 0.5 to 25 mm in the tissue treatment direction from the second opposite surface of the electrode terminal.

29. The system of claim 23 wherein the return electrode is positioned on the shaft proximal to the electrode terminal.

30. The system of claim 23 wherein the electrode terminal is configured to deliver sufficient energy to ablate at least a portion of cartilage strands on the irregular surface of an articular cartilage to smooth said surface.

31. The system of claim 23 wherein the electrode terminal is configured to deliver sufficient energy to heat at least a portion of cartilage strands on the irregular surface of an articular cartilage to smooth said surface.

32. The system of claim 23 further comprising a fluid delivery element for delivering electrically conductive fluid to the electrode terminal.

33. The system of claim 32 wherein the fluid delivery element comprises a fluid lumen on the shaft of the instrument.

34. The system of claim 23 further comprising a temperature controller coupled to the temperature sensor for regulating the power applied to the electrode terminal based on the temperature at a target site.

35. The system of claim 34 further comprising a high frequency power supply coupled to the electrode terminal, wherein the temperature controller adjusts the output voltage of the high frequency power supply in response to a temperature set point and the measured temperature value received from the temperature sensor.

36. The system of claim 34 wherein the temperature controller limits or interrupts current flow to the electrode terminal when the temperature of the temperature sensor reaches a threshold value.

37. The system of claim 23 wherein the electrode terminal comprises a single electrode disposed near the distal end of the shaft.

38. The system of claim 23 wherein the electrode terminal includes an array of electrically isolated electrode terminals disposed near the distal end of the shaft.

39. An electrosurgical system for smoothing body structures having an irregular surface:

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

an electrode terminal disposed at or near the distal end of the shaft;

a return electrode;

an electrically insulating support member having a tissue treatment surface at or near the distal end of the instrument shaft, wherein the electrode terminal is recessed by at least 0.05 mm from the tissue treatment surface of the support member;

at least one connector disposed near the proximal end of the shaft for electrically coupling the electrode terminal and the return electrode to a high frequency voltage source; and

wherein the electrode terminal is sized and constructed to deliver sufficient energy to an irregular surface of a body structure to at least partially smooth the irregular surface of the body structure.

40. The system of claim 39 wherein the electrode terminal is configured to deliver sufficient energy to smooth the irregular surface of the articular cartilage while minimizing the depth of ablation and necrosis in the articular cartilage.

41. The system of claim 39 wherein the return electrode is spaced from the electrode terminal such that when a portion of the electrode terminal is brought adjacent the irregular surface of the body structure immersed in electrically conductive fluid, the electrode terminal is positioned between the return electrode and the body structure and the electrically conductive fluid completes a conduction path between the electrode terminal and the return electrode.

42. The system of claim 41 further comprising a fluid source for supplying the electrically conductive fluid, wherein the electrically conductive fluid has originated from the fluid source, and the fluid source is an external source outside of a patient'"'"'s body.

43. The system of claim 42 wherein the electrically conductive fluid comprises isotonic saline.

44. The system of claim 39 wherein the electrode terminal comprises a tissue treatment surface and a second surface opposite the tissue treatment surface and spaced from the tissue treatment surface in a tissue treatment direction, and wherein the return electrode is spaced about 0.5 to 25 mm in the tissue treatment direction from the second opposite surface of the electrode terminal.

45. The system of claim 39 wherein the return electrode is positioned on the shaft proximal to the electrode terminal.

46. The system of claim 39 wherein the electrode terminal is configured to deliver sufficient energy to ablate at least a portion of cartilage strands on the irregular surface of the articular cartilage to smooth said surface.

47. The system of claim 39 wherein the electrode terminal is configured to deliver sufficient energy to heat at least a portion of cartilage strands on the irregular surface of the articular cartilage to smooth said surface.

48. The system of claim 39 wherein the electrode terminal comprises a single electrode disposed near the distal end of the shaft.

49. The system of claim 39 wherein the electrode terminal includes an array of electrically isolated electrode terminals disposed near the distal end of the shaft.

50. The system of claim 39 further comprising a fluid delivery element for delivering electrically conductive fluid to the electrode terminal.

51. The system of claim 50 wherein the fluid delivery element comprises a fluid lumen on the shaft of the instrument.

52. The system of claim 39 further comprising a high frequency voltage source coupled to the electrode terminal and the return electrode, the voltage source having an operating voltage between about 10 volts RMS and 1000 volts RMS.

53. The system of claim 39 wherein the electrode terminal is disposed over a lateral surface of the electrically insulating support member near the distal end of the shaft.

54. The system of claim 39 further comprising a temperature sensor adjacent to the electrode terminal for controlling power delivery to the electrode terminal.