Method for treating the prostate and inhibiting obstruction of the prostatic urethra using biodegradable stents

• US 20040230316A1
• Filed: 05/12/2003
• Published: 11/18/2004
• Est. Priority Date: 05/12/2003
• Status: Abandoned Application

• Current Assignee: Wit Ip Corporation
• Original Assignee: Wit Ip Corporation
• Inventors: Cioanta, Iulian, Klein, Richard Barry
• Application Number:
  US10/436,804
• Publication Number:
  US 20040230316A1
• Time in Patent Office: Days
• US Class Current: 623/23.66
• 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 2017/00274 Prostate operation, e.g. prostatectomy, turp, bhp treatment
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00238 porous
• CPC Class Codes: A61B 2018/00547 Prostate
• CPC Class Codes: A61M 2025/105 having a balloon suitable for drug delivery, e.g. by using holes for delivery, drug coating or membranes
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence
• CPC Class Codes: A61M 25/1011 Multiple balloon catheters

Abstract

Methods of treating the prostate include administering a thermal ablation therapy and inhibiting the obstruction or closure of the prostatic urethral opening by forming a biodegradable stent in situ in the subject such that the stent attaches to the walls of the prostatic urethra. A related method of treating BPH includes thermally treating or ablating localized tissue in the prostate with a treatment catheter and inserting flowable stent material via the treatment catheter into the prostate (either before, during, or after the thermal treatment), forming the flowable stent material so that it defines a stent that remains in position after removal of the treatment catheter to inhibit the closure of the urinary passage. Associated stents and catheters are included.

Claims

1. A method of treating a condition of the prostate and forming a prostatic stent in situ in the prostatic urethra, comprising:

introducing a catheter having an expandable treatment balloon thereon into the male urethra of the subject so that the treatment balloon resides proximate the prostatic urethra;

administering a thermal ablation therapy to the prostatic urethra of the subject via the treatment catheter, wherein the thermal ablation therapy has a duration of at least about 10 minutes;

releasing biocompatible biodegradeable fluent stent material from the catheter;

activating the stent material in situ to cause it to attach to the interior surface of the prostatic urethra so as to take on a non-fluent form to define a stent having sufficient thickness to inhibit closure of the prostatic urethra after administration of the thermal therapy; and

then removing the treatment catheter such that the stent remains in position in the prostatic urethra.

2. A method according to claim 1, wherein the step of releasing is carried out after initiation of or during the administering step to direct fluent stent material to travel into the acini ducts during the administering step.

3. A method according to claim 1, wherein the step of administering the thermal ablation therapy comprises administering a thermal ablation therapy at a temperature of between about 57-80°

C. for at least a portion of the treatment session, and wherein the step of releasing is carried out before the administering step to thereby direct fluent stent material to flow into the acini ducts during the administering step.

4. A method according to claim 1, wherein the step of releasing is carried out after, but proximate in time to, the administering step.

5. A method according to claim 1, wherein the thermal ablation therapy is carried out for at least about 20-60 minutes, and wherein, after removal of the catheter, the stent has a thickness of at least about 1-2 mm average about the circumference of the prostatic urethra.

6. A method according to claim 1, wherein the stent material is a good heat conductor, and wherein the flowable stent material is configured to be imageable by X-ray to verify the location of the stent in vivo.

7. A method according to claim 1, wherein the treatment catheter has a bladder anchoring balloon disposed above the treatment balloon and an axially extending shaft, said method further comprising:

inflating the bladder anchoring balloon to attach to the bladder neck of the subject prior to the administering step; and

deflating the bladder anchoring balloon prior to the removing step.

8. A method according to claim 2, wherein the administering step comprises expanding the treatment balloon, and the method further comprises:

partially or wholly deflating the treatment balloon during the releasing step pressing the fluent stent material into intimate contact with the interior surface of the prostatic urethra with the expandable treatment balloon; and

pressing the fluent stent material into intimate contact with the interior surface of the prostatic urethra with the expandable treatment balloon.

9. A method according to claim 1, wherein the releasing step comprises directing liquid stent material to flow from a supply located external of the body of the subject through the catheter so that it exits the catheter proximate the prostatic urethra in sufficient quantity, and wherein the method further comprises pressing the fluent stent material into intimate contact with the interior surface of the prostatic urethra with the expandable treatment balloon.

10. A method according to claim 9, wherein said catheter comprises a third expandable sealing balloon located below the treatment balloon so that in the body of the subject it resides above the urinary sphincter, and wherein the method further comprises expanding the third balloon so that it contacts the membraneous urethra during the releasing and activating steps thereby inhibiting the stent material from traveling below the third sealing balloon in the body.

11. A method according to claim 10, wherein the releasing step comprises directing two liquid materials held in fluid isolation in the catheter to exit the catheter separately and mix in situ to form the stent.

12. A method according to claim 10, wherein the releasing step comprises directing the flowable stent material to travel under pressure through the catheter, exit the catheter in at least one dispersing port located below the treatment balloon so that it travels upward in the body to reenter the catheter via at least one flushing port located above the treatment balloon, and exit the body of the subject via the catheter, thereby allowing a clinician to verify that a sufficient quantity of the stent material has been administered over the prostatic urethra.

13. A method according to claim 12, wherein the dispersing port is configured and sized to be larger than the flushing port.

14. A method according to claim 12, wherein the administering step comprises circulating heated fluid in the treatment catheter to expand the treatment balloon with heated fluid so that the expanded balloon contacts the stent material and presses it against the interior surface of the prostatic urethra.

15. A method according to claim 1, wherein the releasing step comprises:

forming a solidified stent material layer onto the outer surface of the treatment balloon; and

applying a first thermal treatment to the solidified material via the treatment balloon to transform the solidified material layer into a flowable viscous form that flowably releases the stent material from the catheter,

and wherein the method further comprises pressing the fluent stent material into intimate contact with the interior surface of the prostatic urethra with the expandable treatment balloon.

16. A method according to claim 15, wherein the activating step comprises applying a second thermal treatment to cause the flowable stent material to resolidify.

17. A method according to claim 16, wherein the first thermal treatment has a greater temperature than the second thermal treatment.

18. A method according to claim 16, wherein the second thermal treatment has a greater temperature than the first thermal treatment.

19. A method according to claim 16, wherein the administering step comprises circulating heated fluid in the treatment catheter to expand the treatment balloon with heated fluid so that the expanded balloon contacts the stent material and presses it against the interior surface of the prostatic urethra.

20. A method according to claim 1, wherein the catheter comprises an expandable permeable sleeve in fluid communication with a liquid material flow port, the sleeve overlying the treatment balloon so that it is concurrently inflatable via inflation of the underlying treatment balloon and configured so as to be separately inflatable from the underlying treatment balloon, wherein the releasing step comprises directing stent material to flow through the catheter, out of the liquid material flow port, and out of the permeable sleeve into the prostatic urethra.

21. A method according to claim 20, wherein the step of directing in the releasing step is carried out while the underlying treatment balloon is wholly or partially deflated.

22. A method according to claim 21, wherein the step of directing is carried out while the underlying treatment balloon is inflated.

23. A method according to claim 20, further comprising pressing the fluent stent material against the internal surface of the prostatic urethra cavity, wherein the treatment balloon is expanded during the administering step, deflated wholly or partially during the releasing step and then expanded again during the activating and pressing steps.

24. A method according to claim 1, wherein the catheter has an elongated, axially extending shaft configured so that an upper portion located above the treatment balloon has a reduced cross-sectional size relative to the portion below the treatment balloon.

25. A method according to claim 1, wherein the activating step is carried out by applying heat at or above a predetermined temperature.

26. A method according to claim 1, wherein the activating step is carried out by exposing the stent material to light.

27. A method according to claim 1, wherein the step of releasing fluent stent material is carried out by separately introducing two flowable substances from the catheter, and wherein the step of activating is carried out by mixing the two substances in situ to cause a chemical reaction.

28. A method of treating BPH, comprising:

thermally ablating localized tissue in the prostate with a treatment catheter having an expandable treatment balloon thereon;

directing fluent viscous or semi-viscous biocompatible biodegradeable stent material from the treatment catheter into the prostate;

expanding the treatment balloon to press the stent material away from the treatment balloon toward the interior surface of the prostatic urethra;

securing the stent material to the prostatic urethra so that it defines a resilient conformable stent that remains in position after removal of the treatment catheter to inhibit the closure of the urinary passage; and

removing the treatment catheter from the body of the subject.

29. A method according to claim 28, wherein the directing step is carried out before the thermal ablating step.

30. A method according to claim 29, wherein the directing step is carried out after the thermal ablating step has been commenced.

31. A method according to claim 28, wherein the directing step is performed after the thermal ablating step is substantially complete.

32. A method according to claim 28, wherein the stent material is directed to enter into a plurality of the acini ducts, wherein the thermal ablating step is carried out for at least about 20-60 minutes, and wherein the resilient stent has a thickness sufficient to maintain a desired urinary flow during the post-treatment healing process.

33. A method according to claim 28, wherein the thermal ablating step comprises:

circulating liquid via a closed loop system where the liquid is heated external of the body of the subject and circulated into the subject in the treatment catheter to a localized treatment region in the prostate for between about 40-60 minutes; and

exposing targeted tissue in the prostate in a localized treatment region to heat at a desired temperature for a predetermined thermal treatment period corresponding to the circulating heated liquid.

34. A method according to claim 33, wherein heat provided by the circulating heated liquid causes the flowable material to become non-fluent and adhere to the interior surface of the prostatic urethra.

35. A method according to claim 34, wherein the flowable stent material comprises a biocompatible and/or biodegradable polymeric matrix.

36. A catheter for treating a condition of the prostate, comprising:

an elongated axially extending shaft;

a treatment balloon secured to the shaft and configured to expand outwardly therefrom, the treatment balloon configured to apply a thermal therapy to targeted tissue in the body;

a bladder-anchoring balloon secured to the shaft above the treatment balloon and configured to expand outwardly from the shaft;

a sealing balloon secured to the shaft below the treatment balloon and configured to expand outwardly from the shaft;

a urinary drainage channel extending through the shaft; and

a flowable biocompatible biodegradable stent material channel having at least one ejection port formed in the shaft associated therewith, the flowable material channel being in fluid isolation with the drainage channel;

wherein the shaft is configured and sized such that the portion intermediate the treatment balloon and anchoring balloon has a decreased cross-sectional width relative to a portion of the shaft intermediate the treatment balloon and sealing balloon, and wherein, in operation, the sealing balloon and the bladder anchoring balloon are in an expanded configuration when flowable biocompatible biodegradable stent material is directed to exit the ejection port.

37. A catheter according to claim 36, further comprising a flushing port and associated flushing channel disposed in the shaft above the at least one ejection port, wherein, in operation, the flushing port is configured to receive flowable stent material therein and direct it to flow out of the body of the subject in the flushing channel that is in fluid isolation from the flowable stent material ejection channel to thereby allow a clinician to verify that the flowable stent material has traveled about the prostatic urethra.

38. A catheter according to claim 37, wherein the flushing port is smaller than the at least one ejection port.

39. A catheter according to claim 36, further comprising inlet and outlet circulating liquid channels in fluid communication with the treatment balloon, wherein the treatment balloon expands responsive to the amount of liquid circulating therethrough.

40. A catheter for treating a condition of the prostate, comprising:

an elongated axially extending shaft;

a treatment balloon secured to the shaft and configured to expand outwardly therefrom;

a bladder-anchoring balloon secured to the shaft above the treatment balloon and configured to expand outwardly from the shaft;

a urinary drainage channel extending through the shaft; and

a non-fluent transformable biocompatible biodegradeable stent material layer formed over the outer surface of the treatment balloon, the stent material being selected such that, when exposed to predetermined temperatures, the stent material becomes fluent and is released from the treatment balloon to flow to surrounding regions in the prostatic urethra and then, upon exposure to at least one of different predetermined temperatures, light, or chemical activation, becomes non-fluent and remains in intimate contact with the interior surface of the prostatic urethra to define a biocompatible biodegradable stent.

41. A catheter according to claim 40, wherein the shaft is configured and sized such that a portion intermediate the treatment balloon and anchoring balloon has a decreased cross-sectional width relative to the portion of the shaft immediately below the treatment balloon.

42. A catheter for treating a condition of the prostate, comprising:

an elongated axially extending shaft;

a treatment balloon secured to the shaft and configured to expand outwardly therefrom;

an outwardly expandable permeable or porous sleeve configured to overlie the treatment balloon, the sleeve being independently inflatable from the treatment balloon;

a quantity of flowable biocompatible biodegradable stent material disposed intermediate the treatment balloon and the sleeve;

a bladder-anchoring balloon secured to the shaft above the treatment balloon and configured to expand outwardly from the shaft;

a sealing balloon secured to the shaft below the treatment balloon and configured to expand outwardly from the shaft;

a urinary drainage channel extending through the shaft; and

a flowable fluent biocompatible stent material channel having at least one ejection port formed in the shaft in fluid communication with the sleeve so as to direct the flowable biocompatible stent material therein, the flowable material channel being in fluid isolation with the drainage channel;

wherein, in operation, the treatment balloon is adapted to inflate to press the flowable stent material released from the sleeve into the targeted tissue in the body.

43. A catheter according to claim 42, wherein the shaft is configured and sized such that the portion intermediate the treatment balloon and anchoring balloon has a decreased cross-sectional width relative to the portion of the shaft intermediate the treatment balloon and sealing balloon.

44. A biodegradable stent for the prostatic urethra defined by a selectively transformable non-fluent biocompatible biodegradable polymeric material in intimate contact with tissue on the surface of the prostatic urethra and configured to extend a distance into a plurality of the acini ducts, the biodegradable stent being resilient and having a sufficient thickness and length to inhibit closure of the urinary flow passage through the prostatic urethra associated with increased inwardly directed pressures associated with inflammation of the prostate or hyperplasia.