Electrosurgical systems and methods for removing and modifying tissue

• US 7,824,398 B2
• Filed: 01/09/2003
• Issued: 11/02/2010
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Tsuji, Craig, Tapliyal, Hira V., Woloszko, Jean, Eggers, Philip E.
• Primary Examiner(s): Cohen; Lee S
• Application Number:
  US10/339,470
• Publication Number:
  US 20030130655A1
• Time in Patent Office: 2,854 Days
• Field of Search: 606/41, 606/45, 606/46, 606/49
• US Class Current: 606/32
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• 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 2018/00148 with metal
• 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 2018/00327 Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00404 : Blood vessels other than those in or around the heart
• 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 2018/00625 : Vaporization
• 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 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00797 : measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00815 : measured by a thermistor
• 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 2018/1213 : 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 2018/1412 : Blade
• CPC Class Codes: A61B 2018/1422 : Hook
• 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 2218/003 : using a spray or a foam
• CPC Class Codes: A61B 2218/007 : Aspiration
• CPC Class Codes: A61F 2/2493 : Transmyocardial revascularisation [TMR] devices

Abstract

The present invention provides systems, apparatus and methods for selectively applying electrical energy to body tissue in order to, ablate, contract, coagulate, or otherwise modify a tissue or organ of a patient. An electrosurgical apparatus includes an electrode support bearing an active electrode in the form of a plasma blade or hook having an active edge and first and second blade sides. The active edge is adapted for severing a target tissue via localized molecular dissociation of tissue components. The first and second blade sides are adapted for engaging against, and coagulating, the severed tissue. s. A method of the present invention comprises positioning an electrosurgical probe adjacent to the target tissue so that a blade- or hook-like active electrode is brought into at least close proximity to the target tissue in the presence of an electrically conductive fluid. A high frequency voltage is applied between the active electrode and a return electrode to effect cool ablation or other modification of the target tissue. During application of the high frequency voltage, the electrosurgical apparatus may be translated, reciprocated, or otherwise manipulated such that the active edge is moved with respect to the tissue. The present invention volumetrically ablates or otherwise modifies the target tissue with minimal or no damage to surrounding, non-target tissue.

Claims

1. A method of modifying a tissue at a target site of a patient'"'"'s body, comprising:

a) providing an electrosurgical probe having a shaft distal end, the shaft distal end bearing an electrode support, and the electrode support having an active electrode affixed thereto, the active electrode consisting essentially of a single blade electrode, the single blade electrode including a distal active edge, a proximal active edge, an active tip, and first and second blade sides, the distal active edge, the proximal active edge, and the active tip each adapted for severing tissue via molecular dissociation of components of the tissue, and the first and second blade sides each adapted for engaging the severed tissue and for coagulating the severed tissue, wherein an entire contact surface of the active electrode is available for severing and coagulating tissue;

b) positioning the shaft distal end in the vicinity of the target site such that the single blade electrode is in at least close proximity to the tissue at the target site; and

c) applying a high frequency voltage between the active electrode and a return electrode in the presence of an electrically conductive fluid, the high frequency voltage sufficient to generate a vapor layer comprising ionic particles proximate each of the distal active edge, the proximal active edge, and the active tip, wherein at least a portion of the tissue at the target site is modified by molecular dissociation so as to volumetrically remove a portion of the tissue at the target site and proximate each of the distal active edge, the proximal active edge, and the active tip, and whereby the vapor layer comprises a high resistance region such that thermal damage to the tissue surrounding the target site is minimized.

2. The method of claim 1, wherein the modified tissue is dissected, transected, incised, or contracted.

3. The method of claim 1, further comprising manipulating the probe such that the active electrode moves in a direction substantially parallel to a surface of the tissue.

4. The method of claim 3, wherein manipulating the probe comprises reciprocating the active electrode with respect to the tissue.

5. The method of claim 1, wherein the single blade electrode comprises a hook.

6. The method of claim 1, further comprising:

moving the distal active edge, the proximal active edge, and the active tip with respect to the tissue, wherein the tissue is severed due to localized molecular dissociation of tissue components in a region of movement of the distal and proximal active edges and the active tip.

7. The method of claim 6, wherein said moving step comprises engaging the active tip against the tissue and drawing the shaft distal end towards an operator.

8. The method of claim 6, further comprising engaging at least one of the first and second blade sides against the severed tissue such that hemostasis of the severed tissue is effected.

9. The method of claim 1, further comprising:

delivering the electrically conductive fluid to the shaft distal end or to the target site such that a current flow path is formed between the active electrode and the return electrode.

10. The method of claim 1, further comprising:

aspirating unwanted materials from the target site via an aspiration lumen.

11. The method of claim 1, wherein the high frequency voltage applied between the active electrode and the return electrode is in the range of from about 10 to 500 volts RMS.

12. The method of claim 1, wherein the tissue at the target site is exposed to a temperature in the range of from about 40°

C. to 70°

C.

13. The method of claim 1, wherein the tissue comprises connective tissue.

14. The method of claim 13, wherein the connective tissue is selected from the group consisting of adipose tissue, cartilage, and bone.

15. A method of modifying a tissue at a target site of a patient, comprising:

a) providing an electrosurgical probe having a shaft distal end, the shaft distal end bearing at least one electrically insulating electrode support, and the at least one electrode support having an active electrode affixed thereto, the active electrode consisting essentially of a hook having a distal active edge, a proximal active edge, an active tip, and first and second sides, the distal and proximal active edges and the active tip each adapted for severing tissue via molecular dissociation of components of the tissue, and the first and second sides each adapted for engaging the severed tissue and for coagulating the severed tissue. wherein an entire contact surface of the active electrode is available for severing and coagulating tissue;

b) positioning the shaft distal end in the vicinity of the target site such that the hook is in at least close proximity to the tissue at the target site; and

c) applying a high frequency voltage between the active electrode and a return electrode in the presence of an electrically conductive fluid, the high frequency voltage sufficient to generate a vapor layer comprising ionic particles proximate each of the distal and proximal active edges and the active tip, wherein at least a portion of the tissue at the target site is modified via molecular dissociation so as to volumetrically remove a portion of the tissue at the target site and proximate each of the distal and proximal active edges and the active tip, and whereby the vapor layer comprises a high resistance region such that thermal damage to the tissue surrounding the target site is minimized.

16. The method of claim 15, further comprising:

d) during said step c), moving the hook with respect to the tissue at the target site, wherein the tissue is severed at the target site.

17. The method of claim 16, wherein the tissue is severed during movement of the shaft distal end portion towards an operator of the probe.

18. The method of claim 16, wherein said step d) comprises engaging the active tip with the tissue at the target site and reciprocating the active tip with respect to the tissue at the target site.

19. A method of resecting a tissue at a target site of a patient'"'"'s body, comprising:

a) positioning an electrosurgical probe in the vicinity of the target site, wherein the probe has a shaft distal end having an electrically insulating electrode support, the electrode support having an active electrode affixed thereto, the active electrode consisting essentially of a hook having a distal active edge, a proximal active edge, an active tip, and first and second sides;

b) positioning the hook in at least close proximity to the tissue at the target site;

c) applying a high frequency voltage between the active electrode and a return electrode spaced proximally away from the active electrode, the high frequency voltage sufficient to generate a high current density at each of the distal active edge, the proximal active edge, and the active tip, such that at least a portion of the tissue at the target site is severed via molecular dissociation of components of the tissue, and wherein the first and second sides engage the severed tissue such that coagulation of the severed tissue is effected as a result of a relatively low current density on the first and second sides, wherein an entire contact surface of the active electrode is available for severing and coagulating tissue.

20. The method of claim 19, further comprising engaging at least the active tip against the tissue and drawing the shaft distal end toward an operator.

21. The method of claim 19, further comprising moving the probe such that the active electrode moves in a direction substantially parallel to the surface of the tissue.

22. The method of claim 19, wherein the tissue comprises connective tissue.