METHOD FOR ABLATING CARDIAC TISSUE

• US 20070135811A1
• Filed: 02/15/2007
• Published: 06/14/2007
• Est. Priority Date: 04/27/2000
• Status: Active Grant

• Current Assignee: Michael Hooven
• Original Assignee: Michael Hooven
• Inventors: Hooven, Michael
• Granted Patent: US 7,543,589 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/2945 Curved jaws
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00363 Epicardium
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00738 Depth, e.g. depth of ablation
• CPC Class Codes: A61B 2018/00755 Resistance or impedance
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/0212 using an instrument inserted into a body lumen, e.g. catheter
• CPC Class Codes: A61B 2018/0225 using an instrument for clamping tissue, e.g. forceps
• CPC Class Codes: A61B 2018/0262 using a circulating cryogenic fluid
• CPC Class Codes: A61B 2018/1432 curved
• CPC Class Codes: A61B 2018/145 wherein the effectors remain parallel during closing and opening

Abstract

A method and apparatus for transmural ablation using an instrument containing two electrodes or cryogenic probes. A clamping force is exerted on the two electrodes or probes such that the tissue of the hollow organ is clamped therebetween. Bipolar RF energy is then applied between the two electrodes, or the probes are cryogenically cooled, thus ablating the tissue therebetween. The method provides for ablating cardiac tissue of a patient utilizing a sub-xyphoid approach and identifying cardiac tissue prior to ablation.

Claims

1. A method for creating an electrically isolated line of ablated tissue in cardiac tissue comprising:

a) clamping cardiac tissue between a pair of jaws each of which carries a conductive member;

b) passing sufficient bi-polar electrical current between the conductive members through the cardiac tissue to form a line of ablation in the cardiac tissue;

c) gauging the completeness of tissue ablation; and

d) indicating to the user when tissue ablation is complete.

2. The method of claim 1 in which gauging the completeness includes monitoring impedance.

3. The method of claim 1 in which gauging the completeness includes monitoring current.

4. The method of claim 1 in which gauging the completeness includes monitoring voltage.

5. The method of claim 1 in which gauging the completeness includes monitoring tissue temperature.

6. The method of claim 2 in which gauging the completeness includes monitoring the change in impedance.

7. The method of claim 1 further including stopping the electrical current when it is gauged that the ablation is transmural.

8. The method of claim 1 in which the completeness of tissue ablation is gauged simultaneously with passing electrical current through the cardiac tissue to form the line of ablation in the tissue.

9. The method of claim 1 further comprising bringing opposed walls of cardiac tissue together and passing current through both walls simultaneously.

10. The method of claim 1 in which the indication to the user that tissue ablation is complete is a visual signal.

11. The method of claim 10 wherein the visual signal is a light.

12. The method of claim 1 in which the indication to the user that tissue ablation is complete is an audible signal.

13. A method for creating an electrically isolated line of ablated tissue in cardiac tissue comprising:

a) clamping cardiac tissue between a pair of jaws each of which carries a conductive member;

b) passing sufficient bi-polar electrical current between the conductive members through the cardiac tissue to form a line of ablation in the cardiac tissue;

c) gauging the completeness of tissue ablation by monitoring one or more of tissue temperature and at least one electrical characteristic relating to ablation; and

d) indicating to the user when tissue ablation is complete.

14. The method of claim 13 in which the at least one electrical characteristic includes impedance and gauging the completeness includes monitoring the impedance.

15. The method of claim 13 in which the at least one electrical characteristic includes current and gauging the completeness includes monitoring the current.

16. The method of claim 13 in which the at least one electrical characteristic includes voltage and gauging the completeness includes monitoring the voltage.

17. The method of claim 13 in which gauging the completeness includes monitoring tissue temperature.

18. The method of claim 14 in which the at least one electrical characteristic includes a change in impedance and gauging the completeness includes monitoring the change in impedance.

19. The method of claim 13 in which the completeness of tissue ablation is gauged simultaneously with passing electrical current through the cardiac tissue to form the line of ablation in the tissue.

20. The method of claim 13 further comprising bringing opposed walls of cardiac tissue together and passing current through both walls simultaneously.

21. The method of claim 13 in which the indication to the user that tissue ablation is complete is a visual signal.

22. The method of claim 21 wherein the visual signal is a light.

23. The method of claim 13 in which the indication to the user that tissue ablation is complete is an audible signal.

24. A method for creating an electrically isolated line of ablated tissue in cardiac tissue comprising:

a) clamping cardiac tissue between a pair of jaws each of which carries a conductive member;

b) passing sufficient bi-polar electrical current between the conductive members through the cardiac tissue to form a line of ablation in the cardiac tissue;

c) gauging the completeness of tissue ablation by monitoring one or more of impedance, current, voltage, tissue temperature, and transmission of an electrical signal across the line of ablation; and

d) indicating to the user when tissue ablation is complete.

25. The method of claim 24 in which gauging the completeness includes monitoring transmission of an electrical signal across the line of ablation.

26. The method of claim 25 in which gauging the completeness includes generating an electrical signal in the tissue on one side of the line of ablation and sensing whether it is transmitted across the line of ablation.

27. The method of claim 24 in which the indication to the user that tissue ablation is complete is a visual signal.

28. The method of claim 27 wherein the visual signal is a light.

29. The method of claim 24 in which the indication to the user that tissue ablation is complete is an audible signal.