Method and system for performing intraurethral radio-frequency urethral enlargement

• US 20030060819A1
• Filed: 08/26/2002
• Published: 03/27/2003
• Est. Priority Date: 02/11/1998
• Status: Active Grant

• Current Assignee: Radionics, Inc. (Integra LifeSciences Holdings Corporation)
• Original Assignee: Radionics, Inc. (Integra LifeSciences Holdings Corporation)
• Inventors: McGovern, Francis J., Cosman, Eric R., Rittman, William J. III, Goldberg, S. Nahum
• Granted Patent: US 6,692,493 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/00505 Urinary tract
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00755 Resistance or impedance
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00815 measured by a thermistor
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2090/3782 transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 2218/002 Irrigation
• CPC Class Codes: A61B 2218/007 Aspiration

Abstract

Relief of urethral obstruction is achieved by heat ablation of prostatic tissue by an ablation electrode passed within the urethra to a position in the prostate near the point of urethral obstruction. The electrode is coupled to a high frequency power supply to ablatively heat the urethra and the prostatic tissue near the urethra. Image guidance of the electrode placement is monitored by an imaging device. The temperature of the tissue is sensed at the electrode to control the high frequency heating energy and ablation process. The electrode has a blunt tip to help prevent piercing of the wall of the urethra during insertion of the electrode into the urethra through the penis and the positioning of the electrode tip near to the point of urethral obstruction. Several forms of electrodes, apparatus, and methods accommodate the specific objectives.

Claims

1. A method of inducing a urethral enlargement at the prostate in an operative field in a patient, which includes a periurethral region of the prostate, comprising the steps of:

inserting an electrode into the urethra through the penis to a region of the prostate within the operative field without piercing the wall of the urethra; and

applying an appropriate level of a high-frequency output from a high-frequency generator through the electrode to induce heat ablation of at least a portion of the urethra and at least a portion of the periurethral tissue within the operative field, thereby inducing formation of a cavity to enlarge a passageway within the urethra.

2. The method of claim 1, further comprising the step of monitoring the position of the electrode in the urethra within the operative field by an ultrasonic scanner inserted in the patient'"'"'s rectum.

3. The method of claim 1, further comprising the step of generating image representations of the electrode for guiding the electrode in the urethra into the region of the prostate in the operative field via a CT or MR imaging scanner.

4. The method of claim 1, and further comprising the step of detecting a temperature level of the tissue proximate to the electrode with a temperature sensor in the electrode coupled to an external temperature monitor.

5. The method of claim 1, further comprising the step of placing an endoscope into the urethra through the penis, and wherein the inserting step comprises inserting the electrode through the endoscope and visualizing, by an optical visualizing channel of the endoscope, the position of the electrode within the urethra.

6. The method of claim 1, wherein the electrode comprises a catheter with a balloon tip, and the inserting step comprises the steps of:

inserting of the catheter into the urethra so that the balloon tip is inside the bladder of the patient; and

inflating the balloon tip so that the catheter is stably positioned in the urethra and that an exposed conductive portion of the electrode is in a fixed position in the urethra proximate to the region of the prostate.

7. The method of claim 1, further comprising the step of generating image representations of the electrode in the region of the prostate with an X-ray imaging apparatus.

8. A method of inducing a urethral enlargement at the prostate within an operative field of a patient, comprising the steps of:

inserting an electrode into the urethra through the penis to a region of the prostate in the operative field without piercing the wall of the urethra;

connecting the electrode to a high-frequency generator located external to the operative field; and

heating the region of the prostate within the operative field by applying an output from the high-frequency generator to the tissue within the operative field through the electrode sufficient to elevate the temperature of a portion of the urethra in the region of the prostate to at least 50°

C. to induce ablation of the portion of the prostate, thereby causing enlargement of the urethra.

9. The method of claim 8, further comprising the step of generating an image representation of the position of the electrode in the prostate by utilizing an imaging apparatus.

10. The method of claim 9, wherein the generating step comprises inserting an ultrasonic image scanner into the rectum of the patient to visualize the prostate and the position of the electrode within the region of the prostate in the operative field.

11. The method of claim 9, wherein the generating step comprises scanning the patient with a CT or MR image scanner to visualize the prostate and the position of the electrode within the region of the prostate in the operative field.

12. The method of claim 8, further comprising the step of passing an endoscope into the urethra through the penis, and wherein the inserting step comprises inserting the electrode through the endoscope and visualizing by an optical visualizing channel the position of the electrode within the urethra.

13. The method of claim 8, wherein the electrode comprises a catheter having a balloon tip, and wherein the inserting step comprises the steps of:

inserting the catheter into the urethra so that the balloon tip is inside the bladder of the patient; and

inflating the balloon tip so that the catheter is stably positioned in the urethra.

14. The method of claim 9, wherein the generating step comprises taking X-ray images to visualize the prostate and the position of the electrode within the prostate.

15. A method for relieving urethral obstruction in a patient with benign prostatic hyperplasia, comprising the steps of:

inserting an electrode into the urethra through the penis to a region of the prostate without penetrating the urethral wall, wherein the electrode has a portion which is uninsulated and has an electrical connection for connecting the portion to a high-frequency generator located external to the body of the patient;

disposing the uninsulated portion within the urethra close to the point of urethral obstruction;

ablatively heating the urethra and the prostate tissue near the urethra by connecting the uninsulated portion of the electrode to the high frequency generator and inducing ablative reduction of tissue mass near the urethra to reduce the urethral obstruction.

16. A system for intraurethral high-frequency heating of an operative field comprising the prostate of a patient to accomplish enlargement of the patient'"'"'s urethra, comprising:

a generator of a high-frequency electrical signal;

an endoscope adapted to be inserted into the urethra through the penis of the patient;

an electrode adapted to be inserted through the endoscope, wherein the electrode has an electrically conductive tip that is blunt to inhibit piercing of the urethral wall and an elongated shaft which is in part electrically insulated, the shaft having a length sufficient to enable the electrically conductive tip to extend out of a distal end of the endoscope and be positioned within the urethra at a position within the prostate; and

an electrical connection between the conductive tip and the generator, allowing the high-frequency electrical signal from the generator to induce ablative heating of a portion of the urethra and a portion of prostate tissue near the urethra when the conductive tip is placed within the urethra at the position within the prostate, thereby causing urethral enlargement.

17. The system of claim 16, wherein the electrode includes a temperature sensor to sense the temperature of the urethra and prostate during heating, and further comprising an external temperature monitoring apparatus coupled to the temperature sensor.

18. The system of claim 16, further comprising:

a temperature-sensing probe adapted for insertion into or adjacent to the prostate to sense the temperature of tissue at a distance from the tip during ablative heating; and

an external apparatus to monitor the temperature as sensed by the temperature-sensing probe.

19. The system of claim 18, wherein the temperature-sensing probe is adapted to be placed proximate to the patient'"'"'s rectal wall to monitor the temperature of the rectal wall during ablative heating.

20. The system of claim 16, further comprising an imaging apparatus to monitor the placement of the tip in the prostate.

21. The system of claim 20, wherein the imaging system is an ultrasonic scanner adapted to be inserted in the rectum of the patient.

22. The system of claim 20, wherein the imaging apparatus comprises a CT or MR imaging scanner.

23. The system of claim 20, wherein the imaging apparatus comprises an X-ray imaging system.

24. The system of claim 16, wherein the endoscope comprises an optical viewing channel adapted to provide visual representations of the position of the electrode within the urethra.

25. A system for intraurethral high-frequency heating of a patient'"'"'s prostate to accomplish enlargement of the patient'"'"'s urethra, comprising:

a generator of a high-frequency electrical signal;

an electrode adapted to be inserted into the urethra through the penis of the patient, wherein the electrode has a non-cooled electrically conductive portion capable of being positioned within the urethra proximate to the prostate; and

an electrical connection between the conductive portion and the generator, allowing the high-frequency electrical signal from the generator to induce ablative heating of a portion of the urethra and a portion of prostate tissue near the urethra, thereby causing urethral enlargement.

26. The system of claim 25, wherein the conductive portion comprises a blunt conductive tip.

27. The system of claim 25, wherein the conductive portion comprises an axially asymmetric conductive tip.

28. The system of claim 25, wherein the conductive portion comprises a pointed tip adapted to pierce the urethra.

29. The system of claim 25, wherein the electrode comprises a catheter, and the conductive portion comprises a conductive ring affixed to the catheter.

30. The system of claim 25, wherein the electrode includes a catheter having an inflatable balloon near a distal end of the catheter, and wherein the balloon can be inflated within the patient'"'"'s bladder to stably position the electrically conductive portion within the urethra proximate to the prostate.