Electro-surgical needle apparatus

• US 20060217704A1
• Filed: 02/06/2006
• Published: 09/28/2006
• Est. Priority Date: 02/04/2005
• Status: Active Grant

• Current Assignee: Instrumedical Limited
• Original Assignee: Instrumedical Limited
• Inventors: Cockburn, Donald James Alexander, Cockburn, John Francis, Wemyss-Holden, Simon
• Granted Patent: US 7,875,025 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• 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 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/0841 for locating instruments
• CPC Class Codes: A61B 8/488 involving Doppler signals

Abstract

A needle assembly (N) for RF ablation of target tissue in e.g. the liver (L) of a patient comprises a radial array of electrodes (1) in the form of loops which can be expanded by feeding the proximal ends of the Y electrodes along the bore of the needle assembly. An RF power supply (2) is connection between the array of electrodes and a skin pad (P) in contact with the skin (S) of a patient and, in accordance with the invention, is biased by a DC power supply 4 which generates electro-osmotic and/or electrolytic effects in the target tissue. In particular, chloride ions are discharged to generate chlorine which has a potent cytocidal effect and water can be attracted to the array of electrodes by electro-osmosis, thereby alleviating the problems of low electrical and thermal conductivity encountered with conventional apparatus.

Claims

1. Surgical apparatus for treating tumours in internal organs or bones of the human body, the apparatus comprising a penetrative needle assembly for penetrating into tumour tissue, energy transfer means coupled to the needle assembly for ablaing target tumour tissue in a region around the needle assembly, and at least one cathode for inducing electro-endosmosis in target tumour tissue in said region.

2. Surgical apparatus according to claim 1, wherein said energy transfer means comprises an AC source coupled to said cathode for generating RF ablation in said region, said AC source generating a power of at least 5 W.

3. Surgical apparatus according to claim 1, wherein said energy transfer means comprises an AC source coupled to said cathode for generating RF ablation in said region, said AC source generating a power of at least 10 W.

4. Surgical apparatus according to claim 1, wherein said energy transfer means comprises an AC source coupled to said cathode for generating RF ablation in said region, said AC source generating a power of at least 20 W.

5. Surgical apparatus according to claim 1, further comprising an anode for insertion into the patient'"'"'s body tissue.

6. Surgical apparatus according to claim 5, wherein said anode is in the form of a needle.

7. Surgical apparatus according to claim 1, further comprising a DC source for biasing said cathode to a negative potential.

8. Surgical apparatus according to claim 7, wherein said negative potential is in the range −

9V to −

12V relative to a positive pole of said DC source.

9. Surgical apparatus according to claim 7, comprising switching means for applying an initial treatment phase in which said cathode is biased to a negative potential to induce electro-endosmosis and for applying a subsequent treatment phase in which said energy transfer means is activated to ablate target tumour tissue hydrated in the initial treatment phase.

10. Surgical apparatus according to claim 1, wherein said needle assembly comprises a cannula and at least one said cathode disposed within and extendable from a distal end of said cannula and shaped to penetrate into target tissue.

11. Surgical apparatus according to claim 10, wherein a plurality of electrodes for inducing electro-endosmosis in target tumour tissue in said region are disposed within and extendable from the distal end of said cannula.

12. Surgical apparatus according to claim 11, wherein said electrodes are all biased with the same polarity, said apparatus further comprising means for establishing an electrical connection of opposite polarity with the body of a patient.

13. Surgical apparatus according to claim 11, wherein one or more of said electrodes are biased with one polarity and one or more others of said electrodes are biased with opposite polarity.

14. Surgical apparatus according to claim 11, further comprising means for selectively reversing the polarity of one or more of said electrodes.

15. Surgical apparatus according to claim 1, wherein said needle assembly has a lumen communicating with a source of conducting liquid or cytocidal substance or precursor thereof for introducing the conducting liquid or substance into said target tumour tissue, said cathode being in electrical contact with said conducting liquid or substance for inducing electro-endosmosis in target tissue in said region.

16. Surgical apparatus according to claim 15, wherein said needle arrangement has a further lumen and further comprising extraction means in communication with said further lumen for extracting liquid, solid or gaseous debris from said target tissue.

17. Surgical apparatus according to claim 1, which includes means for generating electrolysis in said region.

18. Surgical apparatus according to claim 17, wherein said apparatus further comprises ultrasonic imaging means for detecting electrolytically-produced gases in said region.

19. Surgical apparatus according to claim 18, wherein said ultrasonic imaging means is a Doppler ultrasound imager.

20. Surgical apparatus according to claim 1, wherein said needle assembly comprises an extendable electrode array enclosing a volume of tumour tissue for selective ablation of a periphery of said volume of tumour tissue.

23. Sterile surgical apparatus according to claim 1.

21. Surgical apparatus for necrotizing target tissue in internal organs of the human body, the apparatus comprising at least one penetrative anode for penetration into and inducing electrolysis in said target tissue.

22. Surgical apparatus according to claim 21, further comprising means for introducing an electrolyte into said target tissue, said electrolyte being electrolysable to generate a pharmaceutical agent in situ.

24. A method of treatment of a tumour in an organ or bone of the human or an animal body, the method comprising inducing electro-endosmosis in target tumour tissue and separately or simultaneously ablating the target tumour tissue.

25. A method according to claim 24, wherein electro-endosmosis is induced prior to ablating the target tumour tissue.

26. A method according to claim 24, wherein electro-endosmosis is induced for a period of 60 to 600 seconds prior to ablating the target tumour tissue.

27. A method according to claim 24, wherein electro-endosmosis is induced for a period of 120 to 400 seconds prior to ablating the target tumour tissue.

28. A method according to claim 24, wherein electro-endosmosis is induced for a period of 240 to 360 seconds prior to ablating the target tumour tissue.

29. A method according to claim 24, wherein target tumour tissue is ablated by RF ablation apparatus.