Non-Thermal Ablation System for Treating BPH and Other Growths

• US 20100049031A1
• 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 9,211,155 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• 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 minimally invasive method for treating prostate tissue via direct current ablation comprising:

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

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 prostate;

determining treatment parameters;

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

applying between approximately 10 and 50 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 in the treatment zone is created and wherein application of the direct current is substantially non-thermal; and

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 15 and 45 minutes with the catheter in a single treatment position.

2. The method of claim 1, wherein the electrodes are the fixation element and deploying the fixation element and deploying the electrodes comprises one step of deploying the electrodes.

3. The method of claim 1, wherein the treatment zones are created between the bladder neck and verumontanum of the prostate or in the median lobe of the prostate, and wherein the method treats benign prostatic hyperplasia.

4. The method of claim 1, further comprising determining the prostate size to determine input treatment parameters.

5. The method of claim 4, wherein an ultrasound, cystoscopy, MRI, PET, or CT is used to determine the prostate size.

6. The method of claim 4, further comprising determining the transverse width of the prostate to determine input parameters.

7. The method of claim 4, wherein the treatment parameters include at least one of electrode insertion length, charge delivered, current magnitude, and treatment duration, and wherein determining the input parameters comprises comparing information gathered from determining the prostate size against tabulated data.

8. The method of claim 1, wherein the treatment parameters include at least one of electrode insertion length, charge delivered, current magnitude, and treatment duration.

9. The method of claim 1, wherein the fixation element is deployed in the urinary bladder and further comprising using ultrasound to verify the position of the fixation element in the urinary bladder.

10. The method of claim 1, further comprising examining the patient by cystoscopy or ultrasound to determine number of electrodes to be deployed.

11. The method of claim 1, wherein the electrodes are deployed a distance of 14 to 22 mm into the prostate.

12. The method of claim 1, wherein between 2 and 12 electrodes are deployed.

13. The method of claim 1, wherein between 4 and 8 electrodes are deployed.

14. The method of claim 1, wherein the electrodes are deployed into both lateral posterior quadrants, and both lateral anterior quadrants or both lateral quadrants, of tissue relative to the urethra.

15. The method of claim 1, further comprising visualizing at least one of the catheter, the electrodes, and the fixation element during deployment or treatment and wherein visualizing is done by at least one of magnetic resonance, fluoroscopy, and ultrasound imaging.

16. The method of claim 1, further comprising increasing or decreasing the direct current delivered by the electrodes at a controlled ramp rate.

17. The method of claim 16, wherein the ramp rate is between approximately 0.1 mA/sec and 10 mA/sec.

18. The method of claim 1, wherein the current is kept constant throughout the treatment by using voltage compliance to adjust for changing impedance between the electrodes during treatment.

19. The method of claim 1, wherein deploying the fixation element comprises inflating a balloon.

20. The system of claim 19, wherein inflating the balloon comprises inflating the balloon in the bladder.

21. The method of claim 1, wherein the necrotic zone is created with a temperature increase in the prostate of less than 8 degrees.

22. The method of claim 1, wherein the necrotic zone is created with a temperature increase in the prostate of less than that required to cause thermal damage to the tissue.

23. The method of claim 1, further comprising using an indifferent electrode outside the body to complete a treatment circuit with the plurality of electrodes.

24. The method of claim 1, further comprising delivering a charge of between approximately 15 and 72 coulombs to each electrode.

26. The method of claim 1, further comprising delivering a charge of between approximately 24 and 48 coulombs to each electrode.

27. The method of claim 1, further comprising testing impedance of the electrodes in prostate tissue to verify adequate contact.

28. A non-implantable minimally invasive system for treatment of prostate tissue via direct current ablation comprising:

a transurethral catheter for insertion into the urinary tract, wherein a portion of the catheter remains outside of the body when the catheter is in a treatment position proximate the prostate;

a plurality of 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 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,

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

wherein the ablation of tissue is substantially non-thermal.

29. The system of claim 28, wherein the system treats Benign Prostatic Hyperplasia between the bladder neck and verumontanum of the prostate.

30. The system of claim 28, wherein the active area of each electrodes contacting the tissue is between approximately 3 and 12 mm in length.

31. The system of claim 28, wherein each electrode delivers between approximately 24 and 48 coulombs of charge.

32. The system of claim 28, wherein each electrode delivers between approximately 15 and 72 coulombs of charge.

33. The system of claim 28, wherein the electrodes are provided in electrical pairs with each electrode pair consisting of an anode and a cathode.

34. The system of claim 33, wherein the plurality of electrodes comprises of between 2 to 12 electrodes.

35. The system of claim 28, wherein the plurality of electrodes comprises at least four electrodes and wherein a first two of the four electrodes are within a second same transverse plane and a second two of the four electrodes are within a second same transverse plane, with two electrodes on each of two substantially opposing sides of the catheter.

36. The system of claim 35, wherein the two electrodes each of the two substantially opposing sides of the catheter have a deployed angle between them of between approximately 15 and 65 degrees around a longitudinal axis of the catheter.

37. The system of claim 28, wherein the plurality of electrodes are provided in pairs, with each pair being provided at a different transverse plane and wherein consecutive transverse planes of electrodes are axially spaced between approximately 8 and 16 mm.

38. The system of claim 28, wherein the fixation element is a distal fixation element having a proximal edge and a distal edge and wherein distal most electrodes are deployed from the catheter at an axial distance of between approximately 10 and 20 mm from the proximal edge of the distal fixation element.

39. The system of claim 28, wherein the electrodes are deployable from the catheter between approximately 14 and 22 mm into the tissue.

40. The system of claim 28, wherein the electrodes are deployed from the catheter at an angle of approximately 15 to 90 degrees from a longitudinal axis of the catheter.

41. The system of claim 28, wherein a portion of each of the electrodes is insulated.

42. The system of claim 28, wherein the electrodes are configured to resist corrosion.

43. The system of claim 42, wherein the electrodes comprise a nitinol wire with a platinum coating.

44. The system of claim 28, the catheter further comprising a port to drain the bladder

45. The system of claim 28, the catheter further comprising ports for supplying a fluid to buffer the low or high pH created by the electrodes.

46. The system of claim 28, further comprising a rotational actuation mechanism for deploying the electrodes outwardly from the catheter into tissue to be treated.

47. The system of claim 28, further comprising a linear actuation mechanism for deploying the electrodes outwardly from the catheter into tissue to be treated.

48. The system of claim 28, wherein the fixation element is a balloon.

49. The system of claim 28, wherein the fixation element comprises at least one of the plurality of electrodes.

50. The system of claim 28, wherein the treatment parameters include electrode insertion length, charge delivered, treatment duration, or current magnitude.

51. A minimally invasive method for treating prostate tissue via direct current ablation comprising:

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

deploying a fixation element in the urinary bladder, the fixation element being operably coupled to the catheter and operating to fix the catheter in the treatment position;

deploying between approximately 4 and 8 electrodes a distance of approximately 14 to 22 mm into both lateral lobes of the prostate;

determining treatment parameters;

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

applying between approximately 10 and 50 mA of direct current and less than 3200 mW of power to deliver a charge of between approximately 15 and 72 coloumbs 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 in the treatment 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 15 and 45 minutes with the catheter in a single treatment position.

52. The method of claim 51, wherein the method treats Benign Prostatic Hyperplasia between the bladder neck and verumontanum of the prostate.

53. The method of claim 51, wherein determining treatment parameters includes determining prostate size.

54. The method of claim 51, wherein the method imparts a temperature increase in the prostate of less than 8 degrees.