ABLATION DEVICES AND METHODS OF USING THE SAME

• US 20090118727A1
• Filed: 11/05/2007
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: AngioDynamics, Inc.
• Original Assignee: AngioDynamics, Inc.
• Inventors: Douglass, Valerie, Isbell, Lewis, Pearson, Robert
• Granted Patent: US 8,535,306 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1477 Needle-like probes
• 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 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/1425 Needle
• CPC Class Codes: A61B 2090/3925 ultrasonic

Abstract

Devices and methods for ablating a selected tissue volume, such as for ablating tumor, are disclosed. In certain embodiments, the ablation devices include a low-conductivity, tissue-piercing tip, an adjustment mechanism for selectively adjusting the length of an exposed portion of the electrode, for producing ablation volumes of desired geometry. In other embodiment, the methods allow the adjustment of the length of the exposed electrode portion be carried out by moving an insulative sleeve along the electrode.

Claims

1. An ablation device for ablating a selected tissue volume in a patient, comprising:

(a) a hollow, tubular, electrode having a blunt distal end,

(b) a low-conductivity, tissue-piercing, tip snuggly adapted to the distal end of the electrode, and

(c) an insulative sleeve extending over a major proximal portion of the electrode such that the electrode is exposed to a target tissue of the patient only between the sleeve and the tip, wherein

application of RF energy to the exposed portion of the electrode is effective to ablate the selected tissue volume.

2. The device of claim 1, wherein the axial position of a distal end of the sleeve along the electrode is adjustable for selection of different ablation volumes.

3. The device of claim 1, wherein the electrode has one or more openings along the exposed portion for delivery of fluid to the target tissue.

4. The device of claim 1, wherein:

the exposed portion is ultrasonically reflective or radio-opaque, or

either one, or both, of the low-conductivity tip and a distal end of the sleeve is ultrasonically reflective or radio-opaque.

5. An ablation device for ablating a selected tissue volume in a patient, comprising:

(a) an electrode having a central axis,

(b) an insulative sleeve coaxially adapted over a portion of the electrode and is rotatable about the central axis,

(c) a nut through which the electrode passes, the nut being coupled to the sleeve and rotatable about the central axis, and

(d) an adjustment member through which the electrode passes, the adjustment member being movably couple to the nut through an arm, and the nut being rotatable about the central axis, wherein;

rotation of the adjustment member about the central axis is capable of rotating the nut about the central axis and consequently moving the sleeve along the electrode.

6. The device of claim 5, further comprising a handle to which the adjustment member is coupled, and in which the nut is positioned, wherein the handle is transparent or comprises window through which at least a portion of the nut is visible.

7. The device of claim 6, wherein the handle further comprises indicia for identifying an axial length of a portion of the electrode not covered by the sleeve.

8. The device of claim 5, wherein the electrode has one or more openings along the exposed portion for delivery of fluid to the target tissue.

9. The device of claim 5, wherein:

the exposed portion is ultrasonically reflective or radio-opaque, or

a distal end of the sleeve is ultrasonically reflective or radio-opaque.

10. An ablation device for ablating a selected tissue volume in a patient, comprising:

(a) an electrode having a proximal end and a distal end,

(b) a tissue-piercing tip carried on the distal end of the electrode, and

(c) an insulative sleeve extending over a region of the electrode and terminating at a distal end proximal to the distal end of the electrode, such that the electrode is exposed between the sleeve and the electrode distal end,

wherein the length of the exposed portion of said electrode is detectable by virtue of a differential radio-opacity or ultrasound reflectivity between the exposed portion of the electrode and the tip and the sleeve defining the distal and proximal ends of the exposed portion, respectively.

11. The device of claim 10, wherein the electrode has one or more openings along the exposed portion for delivery of fluid to the target tissue.

12. The device of claim 10, wherein:

the exposed portion is ultrasonically reflective or radio-opaque, or

either one, or both, of the tip and a distal end of the sleeve is ultrasonically reflective or radio-opaque.

13. An ablation device for ablating a selected tissue volume in a patient, comprising

an electrode having a single portion exposed to a target tissue, the exposed portion adjoins, on both a distal end and a proximal end, low-conductivity materials, wherein

the exposed portion provides a spheroidal electric field when RF energy is applied thereto, with electric strength equally concentrated on both ends thereof.

14. The device of claim 13, wherein, when RF energy is applied thereto, the exposed portion of the electrode is effective to ablate the selected tissue volume has substantial reflective symmetry with respect to a plane of symmetry of the exposed portion that is orthogonal thereto.

15. The device of claim 13, wherein the selected tissue volume ablated is substantially spheroidal.

16. A method for ablating a selected volume of a patient tissue, comprising

imaging the tissue to determine the location and volume of the selected-volume in the patient tissue,

inserting an electrode of a single-electrode ablation device into the tissue, substantially along one axis thereof,

adjusting the relative axial position of an insulative sleeve on said electrode, to expose a portion of the electrode, such that the exposed electrode portion is substantially coextensive with said selected volume along said axis, and

applying energy to the electrode for a period sufficient to ablate the selected volume.

17. The method of claim 16, wherein the position of the insulative sleeve on said electrode is adjusted prior to said inserting, the electrode has a distal end that can be visualized by tissue imaging, and said inserting includes imaging the electrode tip as the electrode is inserted into the tissue.

18. The method of claim 16, wherein said electrode has one or more openings along the exposed portion for delivery of fluid to the tissue.

19. The method of claim 16, wherein:

the exposed portion is ultrasonically reflective or radio-opaque, or

either one, or both, of the tip and a distal end of the sleeve is ultrasonically reflective or radio-opaque.

20. The method of claim 16, wherein the electrode includes a low-conductivity tip carried on the distal end of the electrode, wherein application of an RF voltage across the electrode is effective to produce an ablation volume whose major axis dimension approximates the combined length of the exposed portion of the electrode and the low-conductivity tip.