Non-Thermal Ablation System for Treating Tissue

• US 20100049188A1
• Filed: 08/19/2009
• Published: 02/25/2010
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: prostaCare Pty Ltd.
• Original Assignee: Ionix Medical, Inc.
• Inventors: Sundquist, Stephen K., Fruland, Benjamin R., Holtz, Michael C., Nelson, Tom A., Kroll, Kai
• Granted Patent: US 9,597,145 B2
• Time in Patent Office: Days
• US Class Current: 606/34
• 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 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00148 with metal
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/00285 Balloons
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00755 Resistance or impedance
• CPC Class Codes: A61B 2018/00767 Voltage
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00982 combined with or comprising means for visual or photographic inspections inside the body, e.g. endoscopes
• CPC Class Codes: A61B 2018/00988 Means for storing information, e.g. calibration constants, or for preventing excessive use, e.g. usage, service life counter
• CPC Class Codes: A61B 2018/1266 with DC current output
• CPC Class Codes: A61B 2018/143 multiple needles
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1475 : Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 2018/1861 : with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61B 2090/378 : using ultrasound
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 34/25 : User interfaces for surgical systems
• CPC Class Codes: A61B 5/055 : involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 8/08 : Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61N 1/36071 : Pain

Abstract

Systems and methods for non-thermal ablation of tissue are provided. A non-implantable minimally invasive system for treatment of tissue in a body via direct current ablation is provided including a catheter, a plurality of electrodes for deployment through the catheter, a power source for applying power to the electrodes, and a fixation element for maintaining the catheter in a treatment position during treatment of the tissue. A minimally invasive method for treating tissue in a body via direct current ablation is provided including inserting a catheter into the body such that a portion of the catheter remains outside of the body, deploying a fixation element to fix the catheter in a treatment position, deploying a plurality of electrodes through the catheter, applying power to the plurality of electrodes, using the electrodes to apply a current to the tissue, and removing the catheter from the body.

Claims

1. A non-implantable minimally invasive system for treatment of issue in a body via direct current ablation comprising:

a catheter for insertion into the body wherein a portion of the catheter remains outside of the body when the catheter is in a treatment position proximate the tissue to be treated;

between 2 and 12 electrodes positioned for deployment through and outwardly from the catheter, wherein an active area of at least one electrode delivers a charge to impart a high pH or a low pH such that a necrotic zone is created to form a field of treatment;

a power source for receiving treatment parameters and applying direct current and power to the plurality of electrodes based on the treatment parameters, wherein the direct current is applied at a magnitude of between approximately 10 and 50 mA per electrode and the power is applied at between approximately 20 and 3200 mW of power per electrode to deliver between 15 and 90 coulombs of charge per electrode,

a fixation element operably associated with the catheter for maintaining the catheter in a treatment position during treatment;

wherein the ablation of tissue using the system is substantially non-thermal.

2. The system of claim 1, wherein the system is configured to treat the prostate.

3. The system of claim 1, wherein the electrodes are provided in electrical pairs with each electrode pair comprising at least one anode and at least one cathode.

4. The system of claim 1, wherein, in a treatment position, the electrodes extend up to 22 mm from the catheter.

5. The system of claim 4, wherein an inserted length of each of the electrodes is approximately the same.

6. The system of claim 4, wherein an inserted length of each of the electrodes varies between at least two of the electrodes.

7. The system of claim 1, wherein distal most electrodes are deployed from the catheter at an axial distance of between 10 and 20 mm from a proximal edge of the fixation element.

8. The system of claim 1, wherein the electrodes are deployed from the catheter at an angle of 15 to 90 degrees from a longitudinal axis of the catheter.

10. The system of claim 1, wherein the plurality of electrodes comprise 4 to 8 electrodes.

11. The catheter of claim 1, wherein at least 4 electrodes are within a same transverse plane.

12. The catheter of claim 1, wherein the plurality of electrodes comprises a first set of 4 electrodes within a first transverse plane and a second set of 4 electrodes within a second transverse plane.

13. The catheter of claim 12, wherein the first transverse plane and the second transverse plane are axially spaced between approximately 8 and 16 mm.

14. The system of claim 1, wherein the catheter is pre-shaped in a curve to approximate anatomy.

15. The system of claim 1, wherein a portion of each of the electrodes is insulated.

16. The system of claim 1, wherein the electrodes are corrosion resistant.

17. The system of claim 16, wherein the electrodes comprise a nitinol wire with a platinum coating.

18. The system of claim 1, wherein the plurality of electrodes include anode electrodes and cathode electrodes and wherein the anode electrodes are corrosion resistant.

19. The system of claim 1, wherein the power source maintains constant current throughout treatment by using voltage compliance to adjust for changing impedance during the treatment.

20. The system of claim 1, wherein the catheter further includes a port for draining fluid.

21. The system of claim 1, wherein the catheter further includes ports for supplying fluid to buffer acid or alkaline reaction in the tissue adjacent to the catheter.

22. The system of claim 1, further comprising a rotational actuation mechanism for deploying the electrodes outwardly from the catheter into tissue to be treated.

23. The system of claim 1, further comprising a linear actuation mechanism for deploying the electrodes outwardly from the catheter into tissue to be treated.

24. The system of claim 1, wherein the fixation element is a balloon or an airless anchor.

25. The system of claim 1, wherein at least one of the electrodes comprises the fixation element.

26. The system of claim 1, wherein the power source displays predicted areas of necrosis over an uploaded image from ultrasound or other form of imaging

27. The system of claim 1, wherein the power source includes between 1 and 6 independent isolated current sources with each current source controlling 1 pair of electrodes.

28. The system of claim 1 wherein the power source is portable.

29. The system of claim 1 wherein the power source controls the treatment with inputted treatment parameters.

30. The system of claim 1 wherein the power source detects whether the catheter is properly electrically attached to the generator.

31. The system of claim 1 wherein the generator is inputted with the size parameters of required lesion or target area.

32. The system of claim 1, wherein the power source includes controls for increasing or decreasing the magnitude of direct current magnitude during treatment.

33. The system of claim 1, wherein the power source includes a mechanism for detecting prior use of the catheter.

34. The system of claim 1, wherein the power source automatically pauses the treatment after sensing a large increase in impedance.

35. The system of claim 34, wherein the power source automatically restarts the treatment after a period of time after pausing the treatment due to sensing a large increase in impedance.

36. The system of claim 1, wherein the catheter includes vacuum ports for applying a vacuum to draw the tissue to the catheter or electrodes.

37. The system of claim 1, wherein the plurality of electrodes deployed from the catheter are of the same electrical polarity and an indifferent electrode is placed outside the body.

38. The system of claim 1, wherein the catheter is semi-flexible with a flex modulus of between about 0.4 and 3 GPa.

39. A minimally invasive method for treating tissue in a body via direct current ablation comprising:

inserting a catheter into the body, wherein a portion of the catheter remains outside of the body when the catheter is in a treatment position;

deploying a fixation element associated with the catheter to fix the catheter in the treatment position;

deploying a plurality of electrodes through the catheter into the tissue proximate the catheter;

determining treatment parameters;

inputting the treatment parameters into at least one of a power source and a processor;

applying between approximately 10 and 100 mA of direct current and less than 3200 mW of power to deliver a charge to the electrodes using a power source, wherein the direct current applied is based on the treatment parameters;

wherein at least one of a high pH and a low pH is imparted by at least one of the electrodes upon application of the direct current such that a necrotic zone is created and wherein application of the direct current is substantially non-thermal;

stopping the application of direct current to the treatment area once the treatment parameters are reached, wherein the application of current to the electrodes is done in between approximately 8 and 100 minutes with the catheter in a single treatment position.

40. The method of claim 39, further comprising determining desired lesion size or targeted area in the body to determine input treatment parameters.

41. The method of claim 40, wherein the input treatment parameters include electrode insertion length, charge delivered, treatment duration, or current magnitude.

42. The method of claim 40, wherein an ultrasound, endoscopy, MRI, PET, or CT is used to determine the targeted area in the body.

43. The method of claim 39, further comprising visualizing the treatment system during deployment or treatment using magnetic resonance, ultrasound, or fluoroscopy.

44. The method of claim 39, wherein deploying the fixation element comprises inflating a balloon or deploying the plurality of electrodes.

45. The method of claim 39, wherein the treatment imparts a temperature increase in the tissue of less than that required to cause thermal damage to the tissue.

46. The method of claim 39, wherein a charge of 15 to 90 coulombs is delivered to each electrode.

47. The method of claim 39, wherein inserting a catheter into the body comprises inserting the catheter into a body lumen, and wherein deploying the plurality of electrodes comprise deploying in tissue on both lateral sides of the catheter.

48. The method of claim 39, wherein inserting a catheter into the body comprises inserting the catheter into a body lumen, and wherein deploying the plurality of electrodes comprise deploying in tissue on one side of the catheter.

49. A non-implantable minimally invasive system for treatment of issue in a body via direct current ablation comprising:

a semi-flexible trans-lumen catheter for insertion into the body wherein a portion of the catheter remains outside of the body when the catheter is in a treatment position proximate the tissue to be treated;

between 2 and 12 electrodes having an insulated portion and an active portion, wherein each electrode has a total length of 14 to 22 mm with the active portion having a length of between 3 and 12 mm, wherein the active portion of at least one of the electrodes delivers a charge to impart a high pH or a low pH such that a necrotic zone is created;

wherein the electrodes are positioned for deployment through and outwardly from the catheter at an angle of 15 to 90 degrees from a longitudinal axis of the catheter, a power source for receiving treatment parameters and applying direct current and power to the plurality of electrodes based on the input parameters, wherein the direct current is applied at a magnitude of between approximately 10 and 50 mA per electrode and the power is applied at between approximately 20 and 3200 mW of power per electrode to deliver between 15 and 90 coulombs of charge per electrode; and

a fixation element operably associated with the catheter for maintaining the catheter in the treatment position during treatment;

wherein the ablation of tissue using the system is substantially non-thermal.

50. The system of claim 49, where is it configured to treat the prostate.

51. The system of claim 49, wherein the distal most electrodes are deployed from the catheter at an axial distance of between 10 and 20 mm from the proximal edge of the distal fixation element.

52. The system of claim 49, wherein the catheter is pre-shaped in a curve to approximate the shape of male urinary tract.

53. The system of claim 49, wherein the electrodes are configured to resist corrosion.

54. The system of claim 49, wherein the electrodes comprise a nitinol wire with a platinum coating.

55. The system of claim 49, wherein the semi-flexible catheter has a flex modulus of between about 0.4 and 3 GPa.