Apparatus and method for RF ablation into conductive fluid-infused tissue

• US 20040006336A1
• Filed: 07/02/2002
• Published: 01/08/2004
• Est. Priority Date: 07/02/2002
• Status: Abandoned Application

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Swanson, David K.
• Application Number:
  US10/188,487
• Publication Number:
  US 20040006336A1
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/143 multiple needles
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

A radiofrequency (RF) ablation device includes a cannula having a proximal end, a distal end, and a lumen extending therethrough. At least one electrode having a lumen and plurality of ports is disposed within the cannula. The electrode can reciprocate between a proximally retracted position and a distally extended position. The at least one electrode is coupled to a source of pressurized conductive fluid. The RF ablation device is used to pre-treat a region of tissue with a high-pressure injection of conductive fluid prior to the delivery of RF energy to the tissue. The pre-treatment step aids in creating extremely large lesions within the tissue.

Claims

1. A radiofrequency ablation device comprising:

a cannula having a proximal end, a distal end, and a lumen extending therethrough;

a plurality of pre-shaped electrodes disposed in the cannula lumen to reciprocate between a proximally retracted position and a distally extended position, the plurality of electrodes including a lumen extending through at least a portion therethrough, the plurality of electrodes further including a plurality of ports provided along at least a portion of each of the plurality of electrodes;

a source of pressurized conductive fluid coupled to the electrode lumens; and

wherein in the proximally retracted position all of the plurality of electrodes are radially constrained within the lumen of the cannula and wherein in the distally extended position all of the plurality of electrodes deploy radially outward.

2. The radiofrequency ablation device of claim 1, wherein the plurality of electrodes includes at least three electrodes.

3. The radiofrequency ablation device of claim 1, further comprising a core disposed coaxially within the cannula and radially inward from the plurality of electrodes.

4. The radiofrequency ablation device of claim 3, wherein the core is reciprocable with the plurality of electrodes.

5. The radiofrequency ablation device of claim 1, wherein the source of pressurized fluid produces a pressure at the proximal end of the electrodes within the range of about 1000 psi to about 2000 psi.

6. The radiofrequency ablation device of claim 1, wherein the source of pressurized fluid produces a pressure at the ports of the electrodes within the range of about 500 psi to about 1500 psi.

7. The radiofrequency ablation device of claim 1, wherein the plurality of electrodes comprise stainless steel hypotube.

8. The radiofrequency ablation device of claim 1, wherein each electrode contains between 20 and 40 ports.

9. The radiofrequency ablation device of claim 1, wherein the plurality of ports have an internal diameter within the range of about 0.002″

to about 0.004.″

10. The radiofrequency ablation device of claim 1, further comprising a temperature probe having a temperature sensor located centrally to the plurality of electrodes.

11. The radiofrequency ablation device of claim 1, wherein the conductive fluid is saline.

12. The radiofrequency ablation device of claim 1, further comprising a radiofrequency generator connected to the plurality of electrodes.

13. The radiofrequency ablation device of claim 1, further comprising a source of vacuum coupled to the lumen of the cannula.

14. The radiofrequency ablation device of claim 1, wherein the plurality of ports are disposed around the entire circumference of at least one electrode.

15. A radiofrequency ablation device comprising:

a cannula having a proximal end, a distal end, and a lumen extending therethrough;

an electrode disposed in the cannula lumen to reciprocate between a proximally retracted position and a distally extended position, the electrode including a lumen extending through at least a portion therethrough, the electrode further including a plurality of ports provided along at least a portion of the length of the electrode;

a source of pressurized conductive fluid coupled to the electrode lumen.

16. The radiofrequency ablation device of claim 15, wherein the source of pressurized fluid produces a pressure at the proximal end of the electrode within the range of about 1000 psi to about 2000 psi.

17. The radiofrequency ablation device of claim 15, wherein the source of pressurized fluid produces a pressure at the ports of the electrode within the range of about 500 psi to about 1500 psi.

18. The radiofrequency ablation device of claim 15, wherein the electrode comprises a closed end, hollow needle.

19. The radiofrequency ablation device of claim 18, wherein the closed end, hollow needle has an internal diameter within the range of about 2 mm to about 3 mm.

20. The radiofrequency ablation device of claim 18, wherein adjacent ports are separated by a distance of about 5 mm.

21. The radiofrequency ablation device of claim 18, wherein the ports are spaced evenly around the circumference of at least a portion of the closed end, hollow needle.

22. The radiofrequency ablation device of claim 15, wherein the conductive fluid is saline.

23. The radiofrequency ablation device of claim 15, further comprising a radiofrequency generator connected to the plurality of electrodes.

24. The radiofrequency ablation device of claim 15, further comprising a source of vacuum coupled to the lumen of the cannula.

25. A method of performing radiofrequency ablation on tissue comprising the steps of:

positioning a radiofrequency ablation device within a region of tissue;

deploying at least one electrode within the region of tissue;

injecting, under pressure, a conductive fluid into the region of tissue with the at least one electrode; and

delivering RF power to the region of tissue using the at least one electrode.

26. The method of claim 25 further comprising the step of irrigating the region of tissue with a conductive fluid when RF power is applied.