METHOD FOR ABLATING WITH NEEDLE ELECTRODE

• US 20090069808A1
• Filed: 04/24/2007
• Published: 03/12/2009
• Est. Priority Date: 10/27/2003
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Mest, Robert A., Sapp, John L. JR., Pike, Robert W. JR., Stevenson, William G.
• Granted Patent: US 9,326,813 B2
• Time in Patent Office: Days
• US Class Current: 606/49
• CPC Class Codes: A61B 18/1477 Needle-like probes
• 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 2018/00351 Heart
• CPC Class Codes: A61B 2018/1425 Needle
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes

Abstract

A method for ablating tissue in or around the heart to create an enhanced lesion is provided. The distal end of a catheter including a needle electrode at its distal end is introduced into the heart. The distal end of the needle electrode is introduced into the tissue. An electrically-conductive fluid is infused through the needle electrode and into the tissue. The tissue is ablated after and/or during introduction of the fluid into the tissue. The fluid conducts ablation energy within the tissue to create a larger lesion than would be created without the introduction of the fluid.

Claims

1. A method for ablating tissue in or around the heart comprising:

introducing into the heart a distal end of a catheter comprising a catheter body and a needle electrode assembly at the distal end of the catheter body, the needle electrode assembly comprising proximal and distal tubings, wherein the distal tubing comprises at least one irrigation port in a sidewall of the tubing, the distal tubing of the needle electrode assembly being in a retracted position within the distal end of the catheter body;

introducing a distal end of the distal tubing of the needle electrode assembly into the tissue, including moving the distal tubing from its retracted position within the distal end of the catheter body to an extended position outside the distal end of the catheter body;

infusing into the tissue an electrically-conductive fluid through the distal tubing of the needle electrode assembly while in the extended position; and

ablating the tissue after and/or during introduction of the fluid into the tissue, whereby the fluid conducts ablation energy within the tissue to create a larger lesion than would be created without the introduction of the fluid.

2. The method according to claim 1, wherein the distal tubing of the needle electrode assembly comprises a closed distal end.

3. The method according to claim 1, wherein the distal tubing of the needle electrode comprises an opening at the distal end of the tubing.

4. The method according to claim 1, wherein the tissue is ablated using the needle electrode.

5. The method according to claim 1, wherein the tissue is ablated using a tip electrode on the distal end of the catheter.

6. The method according to claim 1, wherein fluid is infused through the needle electrode during ablation.

7. The method according to claim 1, wherein fluid is infused through the needle electrode before ablation.

8. The method according to claim 1, wherein fluid is infused through the needle electrode before and during ablation.

9. The method according to claim 1, wherein the fluid infused through the needle electrode comprises saline having a salt content ranging from about 0.3 to about 4 wt %.

10. The method according to claim 1, wherein the fluid infused through the needle electrode comprises a radiographic contrast agent.

11. The method according to claim 1, wherein the amount of contrast agent present in the fluid ranges from about 5 to about 50%.

12. The method according to claim 1, wherein the fluid is infused through the needle electrode a rate ranging from about 0.3 to about 5 ml/min.

13. The method according to claim 1, wherein radiofrequency energy is introduced to the needle electrode at a power up to about 70 watts.

14. The method according to claim 1, wherein radiofrequency energy is introduced to the needle electrode for at least about 15 seconds.

15. The method according to claim 4, further comprising burning a surface lesion with a tip electrode on the catheter, wherein the surface lesion is burned at the endocardial surface of the tissue ablated with the needle electrode.

16. The method according to claim 1, further comprising taking an impedance measurement using the needle electrode before, during and/or after introduction of the distal end of the needle electrode into the tissue.

17. The method according to claim 16, further comprising adjusting the flow rate of the fluid infused through the needle electrode, an amount of power delivered to the needle electrode, and/or the time over which the fluid is infused and/or the power delivered in response to the impedance measurement.

18. The method according to claim 1, further comprising measuring the temperature of the needle electrode during ablation.

19. The method according to claim 18, further comprising adjusting the flow rate of the fluid infused through the needle electrode, an amount of power delivered to the needle electrode, and/or the time over which the fluid is infused and/or the power delivered in response to the temperature measurement.

20. The method according to claim 19, wherein the needle electrode is maintained at a temperature ranging from about 35 to about 90°

C.

21. The method according to claim 1, further comprising measuring electrical activity using the needle electrode before and/or after ablation.

22. The method according to claim 1, further comprising pacing using the needle electrode before and/or after ablation.