ELECTRICAL ABLATION DEVICES AND METHODS

• US 20120220998A1
• Filed: 02/28/2011
• Published: 08/30/2012
• Est. Priority Date: 02/28/2011
• Status: Active Grant

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Long, Gary L., Plescia, David N., Bakos, Gregory J.
• Granted Patent: US 9,314,620 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1206 Generators therefor
• 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 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00613 Irreversible electroporation reversible electroporation A61N1/327
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00672 lower
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00708 switching the power on or off
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61N 1/327 for enhancing the absorption properties of tissue, e.g. by electroporation

Abstract

An electrical ablation device may generally comprise first and second electrodes coupled to an energy source operative to generate and deliver a first sequence of electrical pulses and a second sequence of electrical pulses to tissue having a necrotic threshold, wherein the first sequence of electrical pulses delivers a first energy dose that is less than the necrotic threshold to induce thermal heating in the tissue and the second sequence of electrical pulses delivers a second energy dose equal to or greater than the necrotic threshold to induce cell necrosis in the tissue by irreversible electroporation. The first sequence of electrical pulses may each be independently characterized by a first amplitude, a first pulse width, and a first frequency. The second sequence of electrical pulses may be characterized by a second amplitude, a second pulse width, and a second frequency.

Claims

1. An ablation apparatus, comprising:

first and second electrodes coupled to an energy source operative to generate and deliver a first sequence of electrical pulses and a second sequence of electrical pulses to tissue having a necrotic threshold, wherein the first sequence of electrical pulses delivers a first energy dose that is less than the necrotic threshold to induce thermal heating in the tissue and the second sequence of electrical pulses delivers a second energy dose equal to or greater than the necrotic threshold to induce cell necrosis in the tissue by irreversible electroporation.

2. The ablation apparatus of claim 1, wherein the energy source is operative to generate and deliver a sequence interval between the first sequence and second sequence.

3. The ablation apparatus of claim 1, wherein the first sequence has a first sequence duration and the second sequence has a second sequence duration, and wherein the first sequence duration is greater than the second sequence duration.

4. The ablation apparatus of claim 1, wherein the first sequence has a first sequence total number of pulses and the second sequence has a second sequence total number of pulses, and wherein the first sequence total number of pulses is greater than the second sequence total number of pulses.

5. The ablation apparatus of claim 1, wherein the first sequence comprises a series of first pulse trains each having a first pulse train amplitude, a first pulse train pulse width, and a first pulse train frequency, and the second sequence comprises a series of second pulse trains each comprising a second pulse train amplitude, a second pulse train pulse width, and a second pulse train frequency.

6. The ablation apparatus of claim 5, wherein the first pulse train amplitude is less than the second pulse train amplitude, the first pulse train pulse width is equal to the second pulse train pulse width, and the first pulse train frequency is greater than the second pulse train frequency.

7. The ablation apparatus of claim 5, wherein each of the first pulse trains comprise a plurality of first pulses each having a first amplitude, a first pulse width, and a first frequency, and each of the second pulse trains comprise a plurality of second pulses each having a second amplitude, a second pulse width, and a second frequency.

8. The ablation apparatus of claim 7, wherein the first pulses and the second pulses are each independently characterized by first and second amplitudes in the range of about ±

100 VDC to about ±

10,000 VDC, first and second pulse widths in the range of about 1 μ

s to about 100 ms, and first and second frequencies in the range of about 1 Hz to about 10,000 Hz.

9. The ablation apparatus of claim 7, wherein the first amplitude is less than the second amplitude, the first pulse width is equal to the second pulse width, and the first frequency is equal to the second frequency.

10. The ablation apparatus of claim 7, wherein the plurality of second pulses comprise biphasic pulses.

11. The ablation apparatus of claim 1 comprising at least one of a temperature sensor and a pressure sensor adjacent at least one of the first and second electrodes.

12. The ablation apparatus of claim 1 comprising:

a housing for supporting the first and second electrodes; and

at least one of a temperature sensor and a pressure sensor located within the housing.

13. The ablation apparatus of claim 1 comprising:

a housing having a distal end, a proximal end, and a body extending therebetween for supporting the first and second electrodes;

a temperature sensor located within the housing at the distal end; and

a pressure sensor located within the housing along the body.

14. The ablation apparatus of claim 1 comprising:

a housing having a plurality of vents for supporting the first and second electrodes; and

a pressure sensor located adjacent the plurality of vents.

15. The ablation apparatus of claim 1 comprising:

a sleeve having a distal end for supporting the first and second electrodes;

a first electrode having a positive polarity located at the distal end of the sleeve; and

a second electrode having a negative polarity not located at the distal end of the sleeve.

16. The ablation apparatus of claim 1, wherein the energy source is operative to generate and deliver the second sequence when at least one of a predetermined temperature and a predetermined pressure is achieved.

17. The ablation apparatus of claim 1, wherein the energy source is operative to not generate and not deliver the second sequence when at least one of a predetermined temperature and a predetermined pressure is achieved.

18. A method of treating tissue, comprising:

obtaining the apparatus of claim 1;

inserting the first electrode into the tissue having a necrotic threshold;

applying a first sequence of electrical pulses to the first electrode less than the necrotic threshold to induce thermal heating;

applying a second sequence of electrical pulses to the first electrode to induce cell necrosis by irreversible electroporation; and

applying a ground potential to the second electrode,

wherein the ablation apparatus is operative to reduce the necrotic threshold relative to a corresponding ablation apparatus having an energy source configured to deliver a first sequence of electrical pulses to induce cell necrosis by irreversible electroporation.

19. A method of treating tissue, comprising:

inserting the first electrode into the tissue having a membrane potential and a necrotic threshold;

applying a first sequence of electrical pulses to the first electrode less than the necrotic threshold to induce thermal heating;

applying a second sequence of electrical pulses to the first electrode to induce cell necrosis by irreversible electroporation; and

applying a ground potential to the second electrode.

20. The method of claim 19 comprising:

forming a pre-heated zone by applying an electric field that is less than about 700 V/cm; and

forming a necrotic zone by applying an electric filed that is greater than about 700 V/cm.

21. The method of claim 19 comprising:

heating the mass of tissue by applying an electric field that is less than about 700V/cm to lower the necrotic threshold; and

inducing cell necrosis by irreversible electroporation by applying an electric filed that is greater than about 700 V/cm.

22. The method of claim 19 comprising:

applying a first sequence of electrical pulses to the first electrode less than the necrotic threshold to lower the necrotic threshold;

applying a second sequence of electrical pulses to the first electrode to induce cell necrosis by irreversible electroporation.

23. The method of claim 19 comprising:

lowering the necrotic threshold by heating the tissue by applying an electric field that is less than about 700 V/cm.

24. The method of claim 19 comprising:

lowering the necrotic threshold by 30% by heating the tissue by applying an electric field that is less than about 700 V/cm.

25. The method of claim 19 comprising:

applying a sequence of electrical pulses to increase a membrane potential from less than zero to 100 mV;

applying a sequence of electrical pulses to increase a membrane potential from 100 mV to 500 mV; and

applying a sequence of electrical pulses to increase a membrane potential from 500 mV to the necrotic threshold.

26. The method of claim 19 comprising:

measuring at least one of temperature and pressure adjacent at least one of the first and second electrodes; and

applying a sequence of electrical pulses when at least one of a predetermined temperature and a predetermined pressure is achieved.

27. The method of claim 19 comprising:

measuring at least one of temperature and pressure adjacent at least one of the first and second electrodes; and

stopping a sequence of electrical pulses when at least one of a predetermined temperature and a predetermined pressure is achieved.

28. The method of claim 19 comprising:

measuring at least one of temperature and pressure adjacent at least one of the first and second electrodes; and

applying a sequence of electrical pulses to achieve at least one of a predetermined temperature and a predetermined pressure.

29. The method of claim 19 comprising:

applying a sequence of electrical pulses to the first electrode, the sequence of electrical pulses having amplitudes in the range of about ±

100 VDC to about ±

10,000 VDC, pulse widths in the range of about 1 μ

s to about 100 ms, and frequencies in the range of about 1 Hz to about 10,000 Hz; and

re-applying the sequence of electrical pulses to the first electrode.

30. The method of claim 19 comprising:

applying a sequence of electrical pulses having a first polarity to induce cell necrosis by irreversible electroporation;

applying a sequence of electrical pulses having an opposite polarity to induce cell necrosis by irreversible electroporation.