Apparatus and methods for treating cervical inter-vertebral discs

• US 20030014047A1
• Filed: 06/18/2002
• Published: 01/16/2003
• Est. Priority Date: 06/07/1995
• Status: Active Grant

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Woloszko, Jean, Ormsby, Theodore C., Hovda, David C., Ellsberry, Maria
• Granted Patent: US 7,393,351 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1477 Needle-like probes
• 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 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• 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 2018/00327 : Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00434 : Neural system
• CPC Class Codes: A61B 2018/00505 : Urinary tract
• CPC Class Codes: A61B 2018/00547 : Prostate
• 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 2018/00678 : 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 2018/00827 : 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 2018/1425 : Needle
• 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
• CPC Class Codes: A61B 90/11 : with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61F 2/2493 : Transmyocardial revascularisation [TMR] devices

Abstract

Apparatus and methods for treating an inter-vertebral disc by ablation, coagulation, shrinking, stiffening, or other treatment of disc tissue. A method of the invention includes positioning at least one active electrode within the inter-vertebral disc, and applying at least a first high frequency voltage between the active electrode(s) and one or more return electrode(s), wherein the volume of the nucleus pulposus is decreased, pressure exerted by the nucleus pulposus on the annulus fibrosus is reduced, and discogenic pain of a patient is alleviated. An apparatus of the invention includes an electrosurgical probe, an introducer needle adapted for passing the distal end of the probe therethrough, and a positioning unit for monitoring a position of the probe in relation to the introducer needle.

Claims

1. An active electrode for a medical device, comprising:

a proximal portion comprising a filament; and

a distal electrode head, wherein the electrode head is formed by making a void in a distal portion of the filament, and shaping the void to form a loop.

2. The electrode of claim 1, wherein the loop is shaped to a distal point.

3. The electrode of claim 1, wherein the filament is encased within a first insulating sleeve.

4. The electrode of claim 1, wherein the loop comprises a material selected from the group consisting of platinum, stainless steel, molybdenum, tungsten, titanium, molybdenum, nickel, iridium, and their alloys.

5. The electrode of claim 1, wherein the active electrode comprises a material selected from the group consisting of platinum, stainless steel, molybdenum, tungsten, titanium, molybdenum, nickel, iridium, and their alloys.

6. The electrode of claim 5, wherein the filament comprises a wire having a diameter in the range of from about 0.010 to about 0.012 inches.

7. An electrode for an electrosurgical probe, comprising:

an electrode filament having a filament distal end and a filament proximal end, the filament comprising a first wire and a second wire; and

an electrode head disposed on the filament distal end, the electrode head comprising a distal portion of the first wire and a distal portion of the second wire, wherein the distal portion of the first wire and the distal portion of the second wire are united at an apex of the electrode head.

8. The electrode of claim 7, wherein the electrode head is formed by making at least one fold in a length of insulated wire to form a loop, and removing a layer of insulation from the loop.

9. The electrode of claim 7, wherein the distal portion of the first wire forms a loop with the distal portion of the second wire.

10. The electrode of claim 7, wherein the first wire and the second wire lie substantially parallel to each other at at least the filament distal end.

11. The electrode of claim 7, wherein the apex of the electrode head is shaped to a point.

12. The electrode of claim 7, wherein the first wire and the second wire are affixed to each other at the filament distal end.

14. The probe of claim 13, wherein the active electrode comprises a loop and the loop is shaped to a distal point.

15. The probe of claim 13, wherein the active electrode comprises a distal active electrode head and a proximal electrode filament.

16. The probe of claim 15, wherein the active electrode head is formed by making at least one fold in a wire, and shaping the distal portion of the folded wire to form the loop.

17. The probe of claim 15, wherein the electrode filament comprises a pair of wires, and the pair of wires are fused at a location adjacent to the active electrode head.

18. The probe of claim 15, wherein the electrode filament is encased within an electrically insulating inner sleeve.

19. The probe of claim 13, wherein the shaft includes an electrically conducting cylinder partially encased within an electrically insulating outer sleeve, and the return electrode comprises an exposed distal portion of the electrically conducting cylinder.

20. The probe of claim 13, wherein the shaft consists essentially of an uninsulated electrically conductive material, and the return electrode comprises the shaft.

21. The probe of claim 20, wherein the shaft slidably engages within a lumen of an introducer needle to make electrical contact between the shaft and the introducer needle, and the return electrode further comprises at least a portion of the introducer needle.

22. The probe of claim 13, wherein the shaft distal end is adapted for introduction within a cervical inter-vertebral disc.

23. The probe of claim 13, wherein at least the shaft distal end is adapted for passage within a lumen of a 20 Gauge needle.

24. The probe of claim 15, wherein the active electrode head is rotatable through an angle of up to about 360°

.

25. The probe of claim 15, wherein the active electrode head is expandable from a first unexpanded configuration to at least a second expanded configuration.

26. The probe of claim 13, wherein the extension lead is flexible, and has a length in the range of from about 40 cm to about 80 cm, and a diameter in the range of from about 0.5 mm to about 2.5 mm.

28. The apparatus of claim 27, wherein the positioning unit is integral with the introducer unit.

29. The apparatus of claim 27, wherein the positioning unit is adapted for moving the needle axially relative to the probe.

30. The apparatus of claim 27, wherein the positioning unit is adapted for sequentially positioning the probe at a plurality of probe locations relative to the needle.

31. The apparatus of claim 30, wherein the positioning unit is adapted for locking the probe in each of the plurality of probe locations.

32. The apparatus of claim 30, wherein the plurality of probe locations includes at least a first probe location and a second probe location.

33. The apparatus of claim 32, wherein in the first probe location the electrode assembly is located within the introducer lumen.

34. The apparatus of claim 32, wherein in the second probe location the electrode assembly is located a first distance distal from the needle distal end, wherein the first distance represents a minimum distance between the electrode assembly and the needle distal end for activating the electrode assembly.

35. The apparatus of claim 34, wherein the first distance is in the range of from about 1 mm to about 5 mm.

36. The apparatus of claim 32, wherein the plurality of probe locations further includes a third probe location, and wherein in the third probe location the electrode assembly is located a second distance distal from the needle distal end, wherein the second distance represents a maximum distance between the electrode assembly and the needle distal end.

37. The apparatus of claim 36, wherein the second distance is in the range of from about 10 mm to about 20 mm.

38. The apparatus of claim 27, wherein actuation of the positioning unit moves the needle axially while the probe remains stationary.

39. The apparatus of claim 27, wherein actuation of the positioning unit advances or retracts the needle relative to the probe.

40. The apparatus of claim 39, wherein the positioning unit includes a wheel, and the positioning unit is actuated by rotating the wheel against the shaft.

41. The apparatus of claim 39, wherein the positioning unit includes a ratchet mechanism, and the positioning unit is actuated by actuating the ratchet mechanism.

42. The apparatus of claim 39, wherein the positioning unit is actuated by rotating a screw against a threaded bore.

43. The apparatus of claim 27, wherein the introducer unit includes an introducer stop unit for limiting the penetration of the needle into a patient'"'"'s body.

44. The apparatus of claim 27, wherein the needle includes at least one depth marking on an external surface of the needle for determining a depth of penetration of the needle into a patient'"'"'s body.

45. The apparatus of claim 27, wherein the electrode head is expandable from a first unexpanded configuration to at least a second expanded configuration.

46. The apparatus of claim 27, wherein the probe includes a handle affixed to the shaft proximal end, and a connecting unit, the connecting unit including a connection block and an extension lead, the extension lead distal end affixed to the handle, the extension lead distal end electrically coupled to the active electrode and to the return electrode, the extension lead proximal end electrically coupled to the connection block, and the connection block adapted for coupling the probe to a high frequency power supply.

47. The apparatus of claim 46, wherein the connecting unit includes a connection housing, wherein the connection block is housed within the connection housing.

48. The apparatus of claim 46, wherein the extension lead is flexible and has a diameter in the range of from about 0.5 mm to about 2.5 mm.

50. The system of claim 49, wherein the probe further includes a connecting unit including an extension lead, the extension lead distal end coupled to the active electrode and to the return electrode, and the extension lead proximal end coupled to a connection block.

51. The system of claim 49, wherein the active electrode is located at the distal terminus of the probe.

52. The system of claim 49, wherein the loop is formed by folding a wire to form an electrode head.

53. The system of claim 52, wherein the electrode head is shaped to an apical point.

54. The system of claim 52, wherein the electrode head comprises a substantially rectangular shaped loop.

55. The system of claim 54, wherein the substantially rectangular shaped loop is oriented substantially parallel to the longitudinal axis of the shaft.

56. The system of claim 54, wherein the substantially rectangular shaped loop is oriented at an angle of from about 30°

to 60°

with respect to the longitudinal axis of the shaft.

57. The system of claim 54, wherein the loop is formed by making at least five folds in the wire.

59. The method of claim 58, wherein the introducer needle includes at least one depth marking for monitoring a depth of penetration of the introducer needle into the patient'"'"'s body, and the method further includes:

f) prior to said step a), positioning a needle stop unit on the introducer needle to limit the depth of penetration of the introducer needle into the patient'"'"'s body.

60. The method of claim 58, wherein said step c) comprises positioning the active electrode in relation to the needle distal end such that the active electrode is located within the needle lumen.

61. The method of claim 58, wherein said step d) is performed by actuating a positioning unit, the positioning unit adapted for moving the introducer needle relative to the probe.

62. The method of claim 61, wherein the positioning unit is adapted for sequentially positioning the probe at a plurality of locations relative to the introducer needle.

63. The method of claim 62, wherein the positioning unit is adapted for monitoring a location of the probe relative to the introducer needle.

64. The method of claim 62, wherein the positioning unit is adapted for sequentially locking the probe in each of the plurality of locations.

65. The method of claim 60, wherein said step c) comprises positioning the probe at a first probe location, wherein the active electrode is located adjacent to the needle distal end.

66. The method of claim 58, wherein said step d) comprises retracting the introducer needle such that the active electrode protrudes from the needle distal end by a distance in the range of from about 1 mm to 4 mm.

67. The method of claim 58, wherein the active electrode and the return electrode are coupled to a high frequency power supply capable of operating in at least one of an ablation mode and a sub-ablation mode.

68. The method of claim 58, wherein the active electrode and the return electrode are coupled to a high frequency power supply capable of operating in both an ablation mode and a sub-ablation mode.

69. The method of claim 58, wherein the active electrode comprises an electrode head and an electrode filament, the electrode head in the form of a wire loop.

70. The method of claim 69, wherein the electrode filament comprises of a pair of juxtaposed wires.

71. The method of claim 70, wherein the wire loop is formed by folding a wire to form the pair of juxtaposed wires, and thereafter locally separating the folded wire.

72. The method of claim 58, wherein the target tissue is selected from the group consisting of an errant fragment of the nucleus pulposus, a fissure in the annulus fibrosus, and a contained herniation of the nucleus pulposus.

73. The method of claim 58, wherein the high frequency voltage applied in said step e) is sufficient to ablate the target tissue, and the method further comprises:

g) during said step e) axially translating the shaft distally within the inter-vertebral disc.

74. The method of claim 73, wherein said step g) causes formation of a channel within the nucleus pulposus.

75. The method of claim 74, wherein said step e) comprises applying a first high frequency voltage sufficient to form the channel, the channel having a channel wall, and thereafter applying a second high frequency voltage, the second high frequency voltage sufficient to coagulate, stiffen, or shrink nucleus pulposus tissue adjacent to the channel wall.

76. The method of claim 73, wherein the shaft is rotatable, and the method further comprises:

h) during said step g), rotating the shaft.

77. The method of claim 68, wherein the high frequency voltage applied in said step e) is in the range of from about 70 volts RMS to 350 volts RMS in the ablation mode, and from about 20 volts RMS to 90 volts RMS in the sub-ablation mode.

78. The method of claim 58, wherein the high frequency voltage applied in said step e) is sufficient to effect treatment of the target tissue, and the treatment comprises ablation of the target tissue, stiffening of the target tissue, coagulation of the target tissue, or shrinkage of the target tissue.

79. The method of claim 58, wherein the disc is a cervical inter-vertebral disc.

80. The method of claim 58, further comprising:

i) after said step e), moving the shaft distal end with respect to the disc, and thereafter repeating said step e).

81. The method of claim 58, wherein said step e) causes the volume of the nucleus pulposus to decrease.

82. The method of claim 58, wherein the shaft is engaged within the introducer needle such that the shaft is in electrical contact with the introducer needle, and the shaft in combination with the introducer needle serves as the return electrode.

83. The method of claim 58, wherein the active electrode is expandable between an unexpanded configuration and an expanded configuration.

13. An electrosurgical probe, comprising:

a shaft having a shaft proximal end and a shaft distal end;

an active electrode located at the shaft distal end;

a return electrode located proximal to the active electrode;

a handle affixed to the shaft proximal end; and

a connection unit including a connection block and an extension lead, the extension lead having a lead proximal end and a lead distal end, the lead distal end coupled to the active electrode and to the return electrode, and the lead proximal end coupled to the connection block, the connection block adapted for coupling the probe to a high frequency power supply.

27. An apparatus for performing percutaneous electrosurgical procedures, comprising:

an introducer unit including a needle, the needle having a needle distal end and an introducer lumen within the needle;

an electrosurgical probe, the probe including a shaft and an electrode assembly located at the shaft distal end, the shaft distal end adapted for passage within the introducer lumen, and the electrode assembly including an active electrode having a distal electrode head and a return electrode located proximal to the electrode head; and

a positioning unit for monitoring an axial location of the probe relative to the needle.

49. An electrosurgical system, comprising:

an electrosurgical probe including a shaft having a shaft distal end and a shaft proximal end, and an electrode assembly disposed on the shaft distal end, the electrode assembly including an active electrode and a return electrode located proximal to the active electrode, the active electrode comprising a loop;

a high frequency power supply coupled to the active electrode and to the return electrode, the high frequency power supply adapted for supplying a high frequency voltage between the active electrode and the return electrode in at least an ablation mode or a sub-ablation mode;

an introducer unit including a needle having an introducer lumen therethrough, the introducer lumen adapted for passing the shaft distal end therethrough; and

a positioning unit for positioning the introducer unit relative to the probe.

58. A method of treating a target tissue of an inter-vertebral disc, comprising:

a) inserting an introducer needle into the inter-vertebral disc, the introducer needle having a needle lumen therethrough and a needle distal end;

b) positioning the needle distal end with respect to the target tissue within the inter-vertebral disc;

c) positioning an active electrode of an electrosurgical probe in relation to the needle distal end, the probe including a shaft having a shaft distal end, the active electrode disposed at the shaft distal end;

d) retracting the introducer needle by at least a first distance, wherein the first distance represents a minimum distance, between the active electrode and the needle distal end, for activating the probe; and

e) after said step d), applying a high frequency voltage between the active electrode and a return electrode, the high frequency voltage sufficient to ablate or modify at least a portion of the target tissue.

84. A method of treating a target tissue of an inter-vertebral disc, comprising:

a) introducing a distal portion of an electrosurgical apparatus into the inter-vertebral disc, the apparatus comprising an electrosurgical probe having a shaft and an active electrode disposed on the shaft distal end, an introducer device adapted for passage of the shaft therethrough, and a positioning unit adapted for monitoring a location of the probe in relation to the introducer device;

b) positioning the active electrode into at least close proximity to the target tissue of the disc, wherein the active electrode includes an active electrode filament and an electrode head disposed on the filament distal end; and

c) applying a high frequency voltage between the active electrode and the return electrode, wherein the high frequency voltage is sufficient to ablate or modify the target tissue.

85. The method of claim 84, wherein the electrode filament comprises a pair of juxtaposed wires.

86. The method of claim 84, wherein the electrode head comprises a wire loop, the wire loop comprising a material selected from the group consisting of platinum, stainless steel, molybdenum, tungsten, titanium, molybdenum, nickel, iridium, and their alloys.

87. The method of claim 84, wherein the disc is a cervical disc.

88. The method of claim 84, wherein the active electrode and the return electrode are independently coupled to a high frequency power supply, and the high frequency power supply is capable of operating in at least an ablation mode.

89. The method of claim 84, wherein said step a) comprises:

d) positioning the distal end of the introducer device in the inter-vertebral disc, the introducer device having an introducer lumen therethrough; and

e) positioning the active electrode within the introducer lumen adjacent to the introducer device distal end.

90. The method of claim 89, further comprising:

f) after said step e) and prior to said step c), actuating the positioning unit such that the active electrode protrudes from the introducer device distal end by a distance in the range of from about 1 mm to 4 mm.

91. The method of claim 90, wherein the active electrode protrudes from the introducer device distal end by a distance up to about 20 mm.

92. The method of claim 84, further comprising:

g) during said step c), moving the probe relative to the disc.

93. The method of claim 92, wherein said step g) comprises at least one of:

rotating the shaft and axially translating the shaft.

94. The method of claim 84, wherein the high frequency power supply is switchable between an ablation mode and a sub-ablation mode, and wherein the high frequency voltage applied in said step c) is in the range of from about 70 volts RMS to 350 volts RMS in the ablation mode, and from about 20 volts RMS to 90 volts RMS in the sub-ablation mode.

95. The method of claim 84, wherein the high frequency voltage applied in said step c) is sufficient to effect ablation, stiffening, coagulation, or shrinkage of the target tissue.

96. The method of claim 84, wherein the probe further includes a connecting unit including an extension lead and a connection block, the extension lead for coupling the active electrode and the return electrode to the connection block, and the high frequency power supply coupled to the connection block.

97. The method of claim 96, wherein the extension lead is flexible, and has a diameter in the range of from about 0.5 mm to 2.5 mm, and has a length in the range of from about 50 cm to 70 cm.

98. The method of claim 84, wherein the shaft is engaged within the introducer device such that the shaft is in electrical contact with the introducer device, and the return electrode comprises the shaft in combination with the introducer device.

99. The method of claim 84, wherein the active electrode is adapted for expanding and contracting between an unexpanded configuration and an expanded configuration.

100. A method of treating a target tissue of an inter-vertebral disc, comprising:

a) introducing a distal portion of an electrosurgical apparatus into the inter-vertebral disc, the apparatus comprising an electrosurgical probe and an introducer device, the probe including a shaft having a shaft distal end and an electrically insulating spacer disposed at the shaft distal end, and an active electrode disposed distal to the spacer, wherein the introducer device includes an introducer lumen adapted for passage of the shaft therethrough, and the shaft makes electrical contact with the introducer device when the shaft is engaged within the introducer lumen;

b) positioning the active electrode in at least close proximity to the target tissue; and

c) applying a high frequency voltage between the active electrode and a return electrode, wherein the return electrode comprises the shaft in combination with the introducer device, and the high frequency voltage is sufficient to ablate or modify the target tissue.

101. The method of claim 100, wherein the active electrode includes an active electrode filament and an electrode head disposed on the filament distal end, and wherein the electrode head is expandable.

102. A method of treating a patient experiencing discogenic pain, comprising:

a) inserting an electrosurgical apparatus into a cervical inter-vertebral disc, the apparatus coupled to a high frequency power supply; and

b) applying RF energy to a target tissue within the cervical disc, wherein the discogenic pain is alleviated or eliminated.

103. The method of claim 102, wherein the electrosurgical apparatus includes a shaft having a shaft distal end, an electrode support disposed at the shaft distal end, and an active electrode head disposed on the electrode support, and wherein said step a) comprises positioning the active electrode head within a nucleus pulposus of the cervical disc.

104. The method of claim 103, wherein said step a) comprises advancing an introducer needle into the nucleus pulposus of the cervical disc, and passing the shaft distal end through an introducer lumen of the introducer needle.

105. The method of claim 104, wherein the apparatus further comprises a return electrode, the shaft makes electrical contact with the introducer needle when the shaft is engaged within the introducer lumen, and the return electrode comprises the shaft in combination with the introducer needle.

106. The method of claim 104, wherein the active electrode head and the shaft are independently coupled to the high frequency power supply, and the introducer needle provides a portion of a conductive path between the return electrode and the power supply.

107. The method of claim 103, wherein said step a) comprises applying a first high frequency voltage between the active electrode head and the shaft, the first high frequency voltage sufficient to volumetrically remove at least a portion of the target tissue, wherein the target tissue comprises nucleus pulposus tissue, and whereby the cervical disc is decompressed.

108. The method of claim 103, wherein said step a) comprises applying a second high frequency voltage between the active electrode head and the shaft, the second high frequency voltage sufficient to effect controlled heating of the target tissue, wherein the target tissue comprises nucleus pulposus tissue, the nucleus pulposus tissue is coagulated, stiffened, or contracted, and the cervical disc is decompressed.

109. The method of claim 103, wherein the active elecrode head is expandable between a first unexpanded configuration and a second expanded configuration, wherein the active electrode head adopts the unexpanded configuration during said step a), and the active electrode head adopts the expanded configuration during said step b).