Electrosurgical Device Having Floating Potential Electrode and Adapted for Use With a Resectoscope

• US 20080077129A1
• Filed: 09/21/2007
• Published: 03/27/2008
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: RF Medical, Inc.
• Original Assignee: ElectroMedical Associates, Inc.
• Inventors: Van Wyk, Robert A., Carmel, Yuval, Shkvarunets, Anatoly
• Granted Patent: US 8,177,784 B2
• Time in Patent Office: Days
• US Class Current: 606/46
• 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 18/149 bow shaped or with rotatable body at cantilever end, e.g. for resectoscopes, or coagulating rollers
• CPC Class Codes: A61B 2018/00053 Mechanical features of the instrument of device
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00505 Urinary tract
• CPC Class Codes: A61B 2018/00559 Female reproductive organs
• CPC Class Codes: A61B 2018/00625 Vaporization
• CPC Class Codes: A61B 2018/1213 creating an arc
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/1427 with a beveled end
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

Disclosed herein are embodiments of an electrosurgical device that include one or more floating electrodes and are specifically adapted to remove, cut, resect, ablate, vaporize, denaturize, drill, coagulate and form lesions in soft tissues, with or without externally supplied liquids, preferably in combination with a resectoscope, particularly in the context of urological, gynecological, laparoscopic, arthroscopic, and ENT procedures. Specific adaptations for urological and gynecological applications, for example kidney stone removal and BPH treatment, are also described.

Claims

1. An electrosurgical instrument comprising:

(a) an elongate shaft having a proximal end configured for connection to an electrosurgical power source and a distal end having an electrode assembly mounted thereto;

(b) a conductive member coupled to the elongate shaft and extending between the proximal and distal ends thereof;

(c) an electrode assembly having an active surface that forms an acute angle with the longitudinal axis of the shaft and comprising an active electrode, a floating electrode, and an insulator separating said active and floating electrodes;

wherein said active surface comprises a continuous or discontinuous array of raised and recessed portions that creates regions of high current density for high efficiency vaporization of tissue;

further wherein said insulator is formed from a nonconductive dielectric material while said active and floating electrodes are formed from an electrically conductive material;

further wherein said active and floating electrodes are positioned in close proximity to each other;

further wherein said active electrode is electrically connected to said conductive member while said floating electrode is not connected to either the conductive member or the electrosurgical power source.

2. The electrosurgical instrument of claim 1, wherein said array comprises a plurality of bubble catching grooves.

3. The electrosurgical instrument of claim 1, wherein said array comprises a plurality of cylindrical pins.

4. The electrosurgical instrument of claim 1, wherein the acute angle formed between the active surface of said electrode assembly and the longitudinal axis of said shaft ranges from 20 to 60 degrees, such that said active surface faces the proximal end of said instrument.

5. The electrosurgical instrument of claim 1, wherein the active surface of said electrode assembly has a non-uniform cross-section and takes the shape of a convex spherical segment or a concave spherical segment.

6. The electrosurgical instrument of claim 1, wherein the active surface of said active electrode extends beyond said insulator and said insulator extends beyond said floating electrode.

7. The electrosurgical instrument of claim 1, further comprising an electrode stabilizer mounted to the distal end of the shaft for stabilizing the electrode assembly.

8. The electrosurgical instrument of claim 1, further comprising a pair of parallel tubular members mounted between the distal end of the shaft and the electrode assembly for attaching said electrosurgical instrument to a resectoscope.

9. The electrosurgical instrument of claim 1, wherein said instrument further comprises a return electrode electrically connected to said conductive member.

10. The electrosurgical instrument of claim 1, wherein said active and floating electrodes are formed from a suitable metallic material selected from the group consisting of stainless steel, nickel, titanium, and tungsten whereas the insulator is formed from a suitable dielectric material selected from the group consisting of alumina, zirconia, and high-temperature polymers.

11. The electrosurgical instrument of claim 1, further comprising at least one lumen disposed along the length of said shaft, said lumen configured to deliver an irrigant to the electrode assembly.

12. The electrosurgical instrument of claim 1, further comprising at least one lumen disposed along the length of said shaft, said lumen forming an aspiration path between the active electrode and an external vacuum source.

21. A method of treating benign prostatic hyperplasia (BPH) in a subject in need thereof, comprising the steps of:

(a) inserting a resectoscope outer sheath into the urethra of said subject;

(b) advancing the resectoscope outer sheath until the distal end is adjacent a target site of the prostate of the subject;

(c) advancing a resectoscope working element with telescope and an electrosurgical instrument of claim 1 or 13 through the resectoscope outer sheath to the target site;

(d) introducing an irrigant to the target site so as to submerge the active and floating electrodes of the electrosurgical instrument; and

(e) applying current to the active electrode of the electrosurgical instrument and moving the electrosurgical instrument in a proximal direction relative to the prostate tissue;

wherein step (e) results in vaporization, thermal modification and hemostatic dessication of adjacent prostate tissue.

22. The method of claim 21, wherein the irrigant is selected from the group consisting of non-conductive and conductive fluids.

23. The method of claim 21, wherein the electrosurgical instrument is initially advanced distally past the end of the prostate, extending slightly into the bladder.

24. The method of claim 21, wherein step (e) comprises repeated proximal and distal advancement of the active electrode until the required volume of tissue is removed.

13. An electrosurgical instrument comprising:

(a) an elongate shaft having a proximal end configured for connection to an electrosurgical power source and a distal end having an electrode assembly mounted thereto;

(b) a conductive member coupled to the elongate shaft and extending between the proximal and distal ends thereof; and

(c) a layered electrode assembly comprising;

(i) an active electrode having upper and lower surfaces;

(ii) an insulator having upper and lower surfaces, wherein the upper surface of the insulator is adhered to the lower surface of the active electrode; and

(iii) a floating electrode having upper and lower surfaces, wherein the upper surface of the floating electrode adhered to the lower surface of the insulator;

 

wherein the upper surface of said active electrode comprises an active surface comprised of a continuous or discontinuous array of raised and recessed portions that creates regions of high current density for high efficiency vaporization of tissue;

 

further wherein said insulator is formed from a nonconductive dielectric material while said active and floating electrodes are formed from an electrically conductive material;

 

further wherein said active and floating electrodes are positioned in close proximity to each other;

 

further wherein said active electrode is electrically connected to said conductive member whereas said floating electrode is not connected to either the conductive member or the electrosurgical power source.

14. The electrosurgical instrument of claim 13, wherein said insulator comprises first and second portions, said first portion disposed about a lateral surface of said active electrode and said second portion disposed between said floating electrode and said active electrode so as to electrically insulate the floating electrode from the active electrode.

15. The electrosurgical instrument of claim 13, wherein said layered electrode assembly has a beveled profile.

16. The electrosurgical instrument of claim 13, wherein said layered electrode assembly is mounted to said elongate shaft in such a manner that the active proximal surface of said active electrode faces the proximal end of the instrument.

17. The electrosurgical instrument of claim 13, wherein said layered electrode assembly is mounted to said elongate shaft by means of first and second laterally opposed, distally extending, insulated conductive members having proximal ends mounted to the distal end of said shaft and distal ends received within the active surface of said active electrode.

18. The electrosurgical instrument of claim 13, wherein said lower surfaces of said floating electrode, insulator, and active electrode are approximately parallel.

19. The electrosurgical instrument of claim 13, wherein said array comprises a plurality of bubble trapping grooves.

20. The electrosurgical instrument of claim 13, wherein said array comprises a plurality of cylindrical pins.

27. The electrosurgical instrument of claim 15, wherein the distal surface of said active electrode protrudes beyond the distal surface of said insulator and the distal surface of said insulator protrudes beyond the distal surface of said floating electrode, wherein each of said distal surfaces is beveled, forming an inclined angle of 5 to 50 degrees with the longitudinal axis of the shaft.

25. An electrosurgical instrument comprising:

(a) an elongate shaft having a proximal end configured for connection to an electrosurgical power source and a distal end having an electrode assembly mounted thereto;

(b) a conductive member coupled to the elongate shaft and extending between the proximal and distal ends thereof; and

(c) an electrode assembly mounted to the distal end of the elongate shaft and comprising an active electrode, a floating electrode, and an insulator separating said active and floating electrodes;

 

wherein said insulator is concentrically disposed about said active electrode, and said floating electrode is concentrically disposed about said insulator;

 

wherein said insulator is formed from a nonconductive dielectric material whereas said active and floating electrodes are formed from an electrically conductive material;

 

further wherein said active and floating electrodes are positioned in close proximity to each other;

 

further wherein said active electrode is electrically connected to said conductive member whereas said floating electrode is not connected to either the conductive member or the electrosurgical power source.

26. The electrosurgical instrument of claim 25, wherein said active electrode comprises an elongate portion that extends beyond the distal surfaces of both said floating electrode and said insulator and terminates in a spherical portion or conical point.

28. The electrosurgical instrument of claim 25, wherein said distal surfaces are said floating electrode, insulator, and active electrode are approximately parallel.

29. The electrosurgical instrument of claim 25, wherein the distal surface of said active electrode comprises a plurality of protuberances that create regions of high current density for high efficiency vaporization of tissue.

30. The electrosurgical instrument of claim 25, wherein the distal surface of said active electrode comprises an active surface composed of a continuous or discontinuous array of raised and recessed portions that creates regions of high current density for high efficiency vaporization of tissue.

31. The electrosurgical instrument of claim 25, wherein said array comprises a plurality of bubble trapping grooves.

32. The electrosurgical instrument of claim 25, wherein the floating electrode comprises a cylindrical proximal portion and a flared distal portion, wherein said flared distal portion protrudes beyond the distal surface of said active electrode.

33. The electrosurgical instrument of claim 25, wherein the distal surface of said active electrode extends beyond the distal surface of said insulator, further wherein said active electrode terminates in a sharpened distal tip.

34. The electrosurgical instrument of claim 25, further comprising a lumen disposed between said active electrode and said shaft, said lumen forming an aspiration path between the distal opening of active electrode and an external vacuum source.

35. The electrosurgical instrument of claim 25, further comprising a kidney stone grasping means slidably mounted to the distal portion of the shaft.

36. The electrosurgical instrument of claim 25, further comprising an electrode stabilizer mounted to the distal end of the shaft for stabilizing the electrode assembly.

37. The electrosurgical instrument of claim 25, further comprising a pair of parallel tubular members mounted between the distal end of the shaft and the electrode assembly for attaching said electrosurgical instrument to a resectoscope.

38. The electrosurgical instrument of claim 25, wherein said instrument further comprises a return electrode that is electrically connected to said conductive member.

39. The electrosurgical instrument of claim 25, wherein said active and floating electrodes are formed from a suitable metallic material selected from the group consisting of stainless steel, nickel, titanium, and tungsten whereas the insulator is formed from a suitable dielectric material selected from the group consisting of alumina, zirconia, and high-temperature polymers.

40. The electrosurgical instrument of claim 25, further comprising at least one lumen disposed along the length of said shaft, said lumen configured to deliver an irrigant to the electrode assembly.

41. The electrosurgical instrument of claim 25, further comprising at least one lumen disposed along the length of said shaft, said lumen forming an aspiration path between the active electrode and an external vacuum source.

42. An electrosurgical instrument comprising:

(a) an elongate shaft having a proximal end configured for connection to an electrosurgical power source and a distal end having an electrode assembly mounted thereto;

(b) a conductive member coupled to the elongate shaft and extending between the proximal and distal ends thereof;

(c) first and second laterally opposed, distally extending, insulated conductive members mounted to the distal end of said shaft;

(d) a pair of floating electrodes, one concentrically disposed about the distal end of said first conductive member and the other concentrically disposed about the distal end of said second of conductive member;

(e) a bubble trap mounted to the distal ends of said first and second conductive members; and

(f) an active loop electrode mounted to said bubble trap, extending between said first and second conductive members;

 

wherein said bubble trap is formed from a nonconductive dielectric material while said active loop and floating electrodes are formed from an electrically conductive material;

 

further wherein said at least one active electrode is electrically connected to said conductive member while said at least one floating electrode is not connected to either the conductive member or the electrosurgical power source.

43. The electrosurgical instrument of claim 42, wherein said bubble trap comprises a pair of circular members, one mounted to and projecting radially from the distal end of said first conductive member and the other mounted to and projecting radially from the distal end of said second of conductive member.

44. The electrosurgical instrument of claim 42, wherein said bubble trap comprises a transverse planar component perpendicular to said conductive members and connecting the distal end of said first conductive member to the distal end of said second of conductive member.

45. The electrosurgical instrument of claim 42, further comprising an electrode stabilizer mounted to the distal end of the shaft for stabilizing the electrode assembly.

46. The electrosurgical instrument of claim 42, further comprising a pair of parallel tubular members mounted between the distal end of the shaft and the electrode assembly for attaching said electrosurgical instrument to a resectoscope.

47. The electrosurgical instrument of claim 42, wherein said instrument further comprises a return electrode that is electrically connected to said conductive member.

48. The electrosurgical instrument of claim 42, wherein said active and floating electrodes are formed from a suitable metallic material selected from the group consisting of stainless steel, nickel, titanium, and tungsten whereas the insulator is formed from a suitable dielectric material selected from the group consisting of alumina, zirconia, and high-temperature polymers.