Electrosurgical device and methods

• US 9,241,760 B2
• Filed: 10/25/2012
• Issued: 01/26/2016
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: 9234438 Canada Inc.
• Inventors: Godara, Neil, Woo, Jason, Won, Emily, Gofeld, Michael
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US13/660,353
• Publication Number:
  US 20130060244A1
• Time in Patent Office: 1,188 Days
• Field of Search: 606/21, 606/23
• US Class Current: 1/1
• CPC Class Codes: A61B 18/14 Probes or electrodes 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 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/0044 Spinal cord
• CPC Class Codes: A61B 2018/00565 Bone
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/126 bipolar

Abstract

An electrosurgical bipolar probe with internal cooling for use in systems and methods for lesioning in bone and other tissue is disclosed. The bipolar probe includes tubular electrodes configured such that the inner surface of the electrodes are cooled, directly or indirectly, while keeping the electrodes electrically isolated. An exemplary disclosed method of using a bipolar probe having an active tip having at least two electrodes for delivering energy includes the steps of: advancing the active tip into a bone tissue; delivering energy substantially between the electrodes in a bipolar manner; and supplying cooling fluid to the active tip for internal cooling of the electrodes. Some versions of the method further include the steps of monitoring the temperature of tissue to which the energy is being delivered; and controlling the delivery of energy in response to the temperature of the tissue.

Claims

1. A method of lesioning in bone using a bipolar probe comprising at least two electrodes for delivering energy, the method comprising the steps of:

positioning a portion of the probe comprising the at least two electrodes in a bone tissue;

delivering energy substantially between the at least two electrodes in a bipolar manner; and

internally circulating a cooling fluid within the bipolar probe to cool the at least two electrodes, the portion of the probe comprising the at least two electrodes being substantially closed to the outside environment such that the cooling fluid is not delivered to the outside environment.

2. The method of claim 1 further comprising the steps of monitoring a temperature of the bone tissue to which the energy is being delivered, and controlling delivering energy in response to the temperature of the bone tissue to which the energy is being delivered.

3. The method of claim 1 wherein the bone is a vertebral body.

4. The method of claim 1 wherein the energy is delivered to nervous tissue at a bone-tumor interface.

5. The method of claim 1 wherein the at least two electrodes are positioned in a trabecular bone.

6. The method of claim 3 wherein an introducer assembly, comprising a cannula with a stylet disposed therein, is used to advance the bipolar probe into the vertebral body, and wherein the stylet is withdrawn from the cannula subsequent to the introducer assembly being advanced into the vertebral body.

7. The method of claim 6 wherein the introducer assembly is inserted into the vertebral body using a transpedicular approach.

8. The method of claim 7 wherein the introducer assembly is inserted through a pedicle at an angle of about 15 to about 25 degrees oblique to a mid-saggital plane.

9. The method of claim 6 wherein the introducer assembly is inserted into the vertebral body using a lateral approach.

10. The method of claim 3 wherein:

the bipolar probe is inserted into a vertebral body at a first target location to the right of a mid-saggital plane at an angle of about 15 to about 25 degrees to the mid-saggital plane and energy is delivered to form a first bipolar lesion at the first target location within the vertebral body; and

the bipolar probe is inserted at a second target location to the left of the mid-saggital plane at an angle of about 15 to about 25 degrees from the mid-saggital plane and energy is delivered to form a second bipolar lesion at the second target location within the vertebral body.

11. The method of claim 1 wherein the energy delivered to tissue is radiofrequency energy.

12. The method of claim 2 wherein the temperature of the tissue is maintained at between about 40 degrees and about 100 degrees Celsius.

13. The method of claim 1 wherein the energy is delivered at power levels between about 1 Watt and about 20 Watts.

14. The method of claim 1 wherein the energy is delivered for between about 2 minutes to about 30 minutes.

15. The method of claim 1 wherein the energy is delivered for less than about 2 minutes.

16. The method of claim 1 wherein the energy is delivered for more than about 30 minutes.

17. The method of claim 2 wherein the energy is delivered such that the temperature of the bone tissue increases at a ramp rate from about 10°

C./min to about 80°

C./min.

18. The method of claim 1 further comprising reversing a polarity of the energy to the at least two electrodes.

19. The method of claim 18 further comprising:

delivering a stimulation pulse of energy, comprising a continuous train of biphasic waves at a set frequency, to the bipolar probe;

navigating the at least two electrodes through the bone tissue while delivering the stimulation pulse;

reversing the polarity of the at least two electrodes while delivering the stimulation pulse to identify which electrode a stimulated nerve is in proximity to; and

repeating the steps of delivering a stimulation pulse, navigating the at least two electrodes and reversing the polarity, until a location of the stimulated nerve is determined.

20. The method of claim 2 further comprising:

placing at least one external temperature sensor at a boundary of a desired lesion;

monitoring a boundary temperature using the at least one external temperature sensor during energy delivery; and

determining lesion completion when the external boundary temperature reaches a predefined value.

21. The method of claim 18 wherein each probe is active for about 50 percent of the time.

22. The method of claim 1 wherein a temperature selected for the cooling fluid is from about 0 degrees C. to about 30 degrees C.

23. The method of claim 22 further comprising adjusting a flow rate of the cooling fluid.

24. The method of claim 1 wherein the energy is delivered to a nerve within a vertebral body.

25. The method of claim 24 wherein the energy is delivered to a basivertebral nerve.

26. The method of claim 1, wherein the step of internally circulating a cooling fluid within the bipolar probe comprises supplying the cooling fluid to the bipolar probe and withdrawing the cooling fluid from the bipolar probe.

27. The method of claim 1, wherein the at least two electrodes comprise a distal electrode that defines a distal lumen, and a proximal electrode that defines a proximal lumen, and wherein the step of internally circulating a cooling fluid within the bipolar probe comprises supplying the cooling fluid to the distal lumen, withdrawing the cooling fluid from the distal lumen, supplying the cooling fluid to the proximal lumen and withdrawing the cooling fluid from the proximal lumen.

28. The method of claim 1, wherein the bipolar probe comprises an elongate member and wherein the at least two electrodes are positioned at fixed positions on the elongate member, whereby the step of positioning the at least two electrodes in a bone tissue comprises inserting the elongate member such that the fixed positions of the at least two electrodes are within the bone tissue.

29. The method of claim 26, wherein the at least two electrodes comprise a distal electrode and a proximal electrode, and wherein the step of supplying the cooling fluid to the bipolar probe comprises supplying the cooling fluid to a first location within the bipolar probe that is proximal of the proximal electrode.

30. The method of claim 29, wherein the step of withdrawing the cooling fluid comprises withdrawing the cooling fluid from a second location within the bipolar probe at the distal electrode.

31. The method of claim 26, wherein the step of internally circulating a cooling fluid within the bipolar probe comprises delivering the cooling fluid to a first location within the bipolar probe and withdrawing the fluid from a second location within the bipolar probe, the second location being proximal of the first location.