Multiple antenna ablation apparatus and method

• US 6,958,062 B1
• Filed: 11/03/1997
• Issued: 10/25/2005
• Est. Priority Date: 11/08/1993
• Status: Expired due to Fees

• Current Assignee: AngioDynamics, Inc.
• Original Assignee: Rita Medical Systems Incorporated (AngioDynamics, Inc.)
• Inventors: Edwards, Stuart D., Gough, Edward J., Stein, Alan A.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US08/963,239
• Time in Patent Office: 2,913 Days
• Field of Search: 606/41, 606/42, 606 45- 50, 607/101, 607/102, 607/115, 607/116, 607/122, 607/128
• US Class Current: 606/41
• 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 2018/1425 Needle
• CPC Class Codes: A61B 2018/143 multiple needles
• CPC Class Codes: A61B 2018/1432 curved
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 2018/183 characterised by the type of antenna

Abstract

A multiple antenna ablation apparatus includes an electromagnetic energy source, a trocar including a distal end, and a hollow lumen extending along a longitudinal axis of the trocar, and a multiple antenna ablation device with three or more antennas. The antennas are initially positioned in the trocar lumen as the trocar is introduced through tissue. At a selected tissue site the antennas are deployable from the trocar lumen in a lateral direction relative to the longitudinal axis. Each of the deployed antennas has an electromagnetic energy delivery surface of sufficient size to, (i) create a volumetric ablation between the deployed antennas, and (ii) the volumetric ablation is achieved without impeding out any of the deployed antennas when 5 to 200 watts of electromagnetic energy is delivered from the electromagnetic energy source to the multiple antenna ablation device. At least one cable couples the multiple antenna ablation device to the electromagnetic energy source.

Claims

1. A method of volumetric ablation of tumorous tissue, comprising:

providing a tissue ablation apparatus comprising an elongated delivery device having a tissue piercing distal end and a proximal end, and at least one RF electrode having a tissue penetrating distal portion, said at least one RF electrode being pre-shaped to assume a curved shape and define an ablation volume when deployed;

advancing the elongated delivery device to the selected tissue site, wherein said advancing is effective to place the distal end of the delivery device in or adjacent the tumorous tissue;

deploying said at least one RF electrode from the distalmost end of the elongated delivery device;

delivering energy to a selected tissue site through said at least one RF electrode to ablate said tissue;

monitoring a temperature of said tissue using at least one sensor positioned on said at least one RF electrode, and

modulating delivery of said energy when said temperature reaches a predetermined limit.

2. The method of claim 1, wherein at least a portion of the RF electrode includes an insulator, the method further comprising:

utilizing the insulator to define at least a portion of the ablation volume.

3. The method of claim 1 further comprising adjusting, in response to said measured temperature, said energy level to maintain said temperature at a desired value.

4. The method of claim 1, wherein said at least one sensor is positioned at said distal end of said at least one RF electrode.

5. A method of ablating a tissue mass comprising:

positioning in a patient an ablation apparatus comprising an elongated delivery device and a plurality of electrodes that are pre-shaped to assume a curved shape and define an ablation volume when deployed, wherein said positioning is effective to place the distal tip of the delivery device in or adjacent the tissue mass;

deploying said plurality of electrodes from the distalmost end of the elongated delivery device, thus to define an ablation volume that includes the tissue mass;

applying an ablating current to the deployed electrodes, wherein said tissue mass contained within the defined volume is ablated;

monitoring a characteristic of said tissue mass using at least one sensor positioned on at least one of said electrodes as said tissue mass is being ablated; and

controlling the extent of ablation in response to the characteristic detected at said at least one sensor.

6. The method of claim 5 wherein said sensors are positioned at a distal end of said electrodes.

7. The method of claim 5 further comprising infusing said tissue with an infusion medium.

8. The method of claim 7, wherein said infusion medium is a chemotherapeutic agent.

9. The method of claim 7, wherein said infusion medium is a conductivity enhancement medium.

10. The method of claim 7, wherein at least one of said plurality of electrodes includes a lumen capable of being operatively coupled to an infusion source, and said method further includes infusing a liquid through said electrodes into the defined ablation volume prior to or during said ablating step.

11. The method of claim 5, wherein said sensor is a thermal sensor and said detected characteristic is temperature.

12. The method of claim 11 further comprising adjusting, in response to said monitored characteristic, said energy to maintain said characteristic at a desired value.

13. The method of claim 12, wherein said energy source is a RF source and said electrode is a RF electrode.

14. The method of claim 13, wherein said electrodes, when deployed, have an electromagnetic energy delivery surface of a size sufficient to create a volumetric ablation without impeding out any one of said deployed electrodes when 5 to 200 watts of electromagnetic energy is delivered.

15. The method of claim 5, wherein said controlling step comprises ceasing said applying of energy in response to said characteristic.

16. The method of claim 5, wherein said controlling step comprises modulating said applying of energy in response to said characteristic.

17. The method of claim 5, wherein said ablation apparatus includes an insulator positioned in a surrounding relationship to at least a portion of one of (i) the elongated delivery device, or (ii) at least one of the plurality of electrodes.

18. The method of claim 17, further including positioning said insulator over at least one of the plurality of electrodes to produce a selectable energy delivery surface.

19. The method of claim 5, wherein said detected characteristic is impedance.

20. The method of claim 5, further including localizing the tissue mass by a process selected from the group consisting of ultrasound, computerized tomography scanning, X-ray, magnetic resonance imaging, and electromagnetic imaging.

21. The method of claim 5, wherein said applying an ablating current comprises applying an RF current.

22. The method of claim 5, wherein said applying an ablating current comprises applying a microwave current.