Radiation exposure device for blood vessels, body cavities and the like

• US 6,183,410 B1
• Filed: 05/06/1999
• Issued: 02/06/2001
• Est. Priority Date: 05/06/1999
• Status: Expired due to Fees

• Current Assignee: Precision Vascular Systems, Inc. (Boston Scientific Corporation)
• Original Assignee: Precision Vascular Systems, Inc. (Boston Scientific Corporation)
• Inventors: Backman, Kent, Jacobsen, Stephen C., Davis, Clark C., Lippert, John
• Primary Examiner(s): Hindenburg, Max
• Assistant Examiner(s): SZMAL, BRIAN SCOTT
• Application Number:
  US09/306,079
• Time in Patent Office: 642 Days
• Field of Search: 600/3, 600/4, 600/5, 600/7, 604/500, 604/516, 604/528
• US Class Current: 600/3
• CPC Class Codes: A61N 2005/1005 with asymmetrical radiation pattern
• CPC Class Codes: A61N 5/1002 Intraluminal radiation therapy
• CPC Class Codes: A61N 5/1007 Arrangements or means for the introduction of sources into the body

Abstract

A device and method for irradiating with a desired radioactive emission the interior walls of blood vessels, body cavities and the like. The device includes a catheter for placement in the blood vessel, body cavity or the like, adapted for disposition adjacent the walls thereof. The distal end of the catheter is preferably configured to expand into a helical coil shape when unconstrained, but may be straightened when constrained within a second catheter. The catheter includes a section which is opaque to the radioactive emissions in question, and a wire slidably disposed therein for threading selectable distances into the catheter. A radioactive source is positioned at the distal end of the wire, and when positioned within the radio-opaque section of the catheter, radioactive emissions arc blocked from reaching adjacent tissue, allowing the radiation source to be safely guided to a target location. Upon reaching the target location, the radioactive source is moved out of the opaque section, and radioactive emissions are allowed to reach adjacent tissue for treatment. The radiation source is preferably retracted through the catheter at a variable rate, so as to vary the radiation exposure level of adjacent tissues.

Claims

1. Apparatus for selectively radiating with radioactive emissions the inside surface of blood vessels, body cavities and the like of a patient, said apparatus comprising:

a resilient, elongate guide means configured for threading into and contacting the inside surface of a blood vessel, body cavity or the like, said guide means having a helical section shaped as a coil when unconstrained, yet configured to be straightenable for insertion into and movement through a catheter having a distal end, for discharge therefrom to re-assume a helical coil shape and occupy a target location adjacent said distal end, and having at least one lumen formed therein configured for guiding a radiation source in an arcuate path within the helical coil adjacent an interior wall of said blood vessel, body cavity or the like at the target location;

an elongate wire means slidably disposed within the lumen of the guide means, said wire means including a proximal end and a distal end; and

a radiation source disposed near said distal end configured for exposing the tissue of the blood vessel, body cavity or the like to radioactive emissions.

2. Apparatus as in claim 1 further comprising:

a first catheter for containing and constraining said guide means in a straight configuration for insertion into the patient, said first catheter having a proximal end, a distal end, and a central lumen.

3. Apparatus as in claim 2 wherein said guide means comprises a second catheter having a central lumen, a proximal end, and a distal end, and said elongate wire means comprises a flexible wire disposed within the central lumen of said second catheter and extending from the proximal end to the distal end thereof, the distal end of said second catheter being configured to radially expand into a helical coil and contact the inside surface of the blood vessel, body cavity or the like at the target location when unconstrained, said helical coil having a central hollow whereby the radiation source will be caused to negotiate a helical path through said catheter when the flexible wire is slidably withdrawn from the distal end toward the proximal end of said catheter.

4. Apparatus as in claim 3 wherein said second catheter is formed of materials selected from the group consisting of nickel titanium alloy, stainless steel, and polymeric materials.

5. Apparatus as in claim 3 wherein the outside diameter of said second catheter is no greater than approximately 0.014 inches.

6. Apparatus as in claim 3 wherein the distal tip of said second catheter is absorbent to radioactive emissions from the radiation source, whereby radioactive emissions are substantially blocked from reaching adjacent tissue when the radiation source is positioned within said distal tip.

7. Apparatus as in claim 6 wherein said distal tip is made of a material selected from the group consisting of tungsten and platinum.

8. Apparatus as in claim 6 further comprising a radioactive emission absorbing section formed in the second catheter at a location toward the proximal end thereof relative to the expandable distal end thereof, whereby the radiation source may be retracted into said radioactive emission absorbing section, so as to substantially block radioactive emissions from reaching adjacent tissue.

9. Apparatus as in claim 8, wherein said radioactive emission absorbing section is made of a material selected from the group consisting of tungsten and platinum.

10. Apparatus as in claim 8 wherein said radioactive emission absorbing section comprises a hollow, generally cylindrical section formed in the catheter.

11. Apparatus as in claim 6 wherein the distal end of said first catheter comprises a radioactive emission absorbing section, whereby the first catheter having the radiation source contained therein may be retracted into the distal end of said first catheter, so as to substantially block radioactive emissions from reaching adjacent tissue.

12. Apparatus as in claim 1 wherein said radiation source comprises a source selected from the group consisting of beta radiation emitters and gamma radiation emitters.

13. Apparatus as in claim 12 wherein said beta radiation emitter is formed of a material selected from the group consisting of iridium 192, phosphorus 92, and strontium 90.

14. Apparatus as in claim 3 wherein said helical coil includes a plurality of cuts on the exterior surface thereof, formed to shape said portion into a coil, and provide openings to permit transmission of radiation outwardly from said coil, and to substantially inhibit transmission of radiation toward the interior of said coil.

15. Apparatus as in claim 14, wherein said cuts have a depth approximately equal to 80% of the diameter of said second catheter.

16. Apparatus as in claim 14, further comprising a plurality of cuts on the interior surface of said catheter, said interior cuts formed to shape said portion into a coil, and to generally close when said portion is in the coil configuration, to thereby inhibit transmission of radiation toward the interior of said coil.

17. Apparatus as in claim 4, further comprising:

a plurality of cuts formed on the exterior surface of said catheter so as to shape said distal end into a coil, and provide openings to permit transmission of radiation outwardly from said coil; and

a plurality of cuts formed on the interior surface of said catheter so as to shape said distal end into a coil, and to generally close when said distal end is in the coil configuration, to thereby inhibit transmission of radiation toward the interior of said coil.

18. Apparatus as in claim 17 wherein said cuts are formed by a method selected from the group consisting of cutting, grinding, etching, and EDM.

19. Apparatus as in claim 17 wherein the longitudinal locations of the plurality of cuts formed on the exterior surface and on the interior surface of said catheter are oppositely staggered.

20. Apparatus as in claim 17 wherein the plurality of cuts formed on the exterior surface and on the interior surface of said catheter extend from the outside surface to the central lumen thereof.

21. Apparatus as in claim 20 wherein the coiled section of said second catheter has a diameter approximately equal to 0.014 inches, and said cuts are from approximately 0.001 inches wide to approximately 0.002 inches wide when in an unstressed condition, are from approximately 0.004 inches to 0.012 inches deep, and are longitudinally spaced from approximately 0.004 inches to 0.015 inches apart.

22. Apparatus as in claim 3, further comprising power retraction means for mechanically retracting said flexible wire through the second catheter.

23. Apparatus as in claim 22, wherein said power retraction means further comprises speed adjustment means, whereby the speed of retraction of said flexible wire may be selectively adjusted.

24. An apparatus as in claim 1, further comprising cuts formed in the guide configured to facilitate straitening of the guide to be deployed through the catheter.

25. A device for irradiating with a desired radiation the walls of blood vessels, body cavities and the like of a patient, comprising:

a resilient elongate guide means having a central lumen, a proximal end, and a distal end, the distal end being configured to expand into a helical coil and contact the inside surface of the blood vessel, body cavity or the like at a target location when unconstrained, and to collapse and straighten when constrained for insertion into and movement through a catheter for discharge therefrom to expand and occupy the target location, said helical coil forming a central hollow when unconstrained for allowing bodily fluids to pass therethrough, said guide means being configured for guiding a radiation source contained within the lumen thereof through said helical coil;

a catheter for containing and constraining said guide means in a straight configuration for insertion into the patient;

a flexible wire slidably disposed within the central lumen of said guide means and extending from the proximal end to the distal end thereof, said flexible wire having a proximal end and a distal end, and having a radiation source disposed near the distal end whereby the radiation source will be caused to negotiate a helical path through said catheter when the flexible wire is slidably withdrawn from the distal end toward the proximal end of said catheter; and

a radio-absorptive sleeve formed in the distal tip of said catheter, whereby radioactive emissions from the radiation source are substantially blocked from reaching adjacent tissue when the radiation source is positioned within said sleeve.

26. An apparatus for selectively radiating with radioactive emissions the inside surface of blood vessels, body cavities and the like of a patient, said apparatus comprising:

a catheter having a proximal end and a distal end, and configured for threading into a blood vessel, body cavity or the like, the distal end of said catheter being configured to be straightened for insertion into and movement through a catheter, and configured to expand into a coil so as to contact the inside surface of the blood vessel, body cavity or the like at a target location when unconstrained; and

elongate wire means slidably disposed within the lumen of the catheter, said wire means including a proximal end and a distal end, and having a radiation source disposed near said distal end for exposing the tissue of the blood vessel, body cavity or the like to radioactive emissions when the wire means is slidably withdrawn from the distal end toward the proximal end of said catheter.

27. A method for irradiating the walls of a blood vessel, body cavity or the like with a desired radiation, said method comprising the steps of:

inserting an elongate hollow guide means into a blood vessel, body cavity or the like of a patient, such that the distal end of the guide means is located adjacent a target location, the guide means having a flexible wire slidably disposed within a central lumen thereof, said flexible wire having a radiation source disposed near its distal end, and enclosed in a radiation absorbtive section formed at the distal end of said guide means to shield tissue from radiation exposure;

expanding the distal end of the guide means into a helical coil so as to contact the inside surface of the blood vessel, body cavity or the like at the target location, said coil forming a central hollow for allowing bodily fluids to pass therethrough;

retracting the flexible wire through the guide means so as to draw the radiation source from the radiation absorbtive section at the distal end of the guide means, through the helical coil, toward the proximal end thereof, so as to irradiate the walls of the blood vessel, body cavity or the like; and

withdrawing the guide means from the patient.

28. The method as in claim 27, wherein the step of retracting the wire so as to draw the radiation source through the coiled guide means further comprises the step of

retracting the flexible wire at a variable speed, whereby the radiation source is located proximal to the portions of the anatomy requiring more radiation exposure for a longer time interval.

29. The method as in claim 27, further comprising the step of:

tracking the position of the distal end of said guide means while threading said apparatus into the anatomy of the patient; and

tracking the position of said radiation source while retracting the flexible wire through the coiled guide means.

30. The method as in claim 27, wherein the step of withdrawing the apparatus from the patient further comprises the steps of:

retracting the radiation source into a radioactive emission absorbing section formed in the guide means at a location toward the proximal end thereof relative to the helically formed distal end thereof, to shield tissue from radiation exposure; and

withdrawing the guide means from the patient with the radiation source contained within the radioactive emission absorbing section.

31. The method as in claim 27, wherein the step of inserting the guide means into the patient further comprises the steps of:

threading an elongate catheter into the blood vessel, body cavity or the like of the patient, such that the distal end of said catheter is advanced to a point near the target location; and

inserting the guide means in a straightened condition into the lumen of said catheter and advancing said guide means so as to place its distal end adjacent to the target location.

32. The method as in claim 31 wherein the step of expanding the distal end of the guide means into a helical coil comprises the step of:

advancing said guide means beyond the distal end of said catheter, whereby the guide means may be unconstrained.

33. The method as in claim 31 wherein the step of expanding the distal end of the guide means into a helical coil comprises the step of:

retracting the distal end of said catheter from around the distal end of said guide means, whereby the guide means may be unconstrained.

34. The method as in claim 31 wherein the step of withdrawing the guide means from the patient further comprises the steps of:

retracting the radiation source into a radioactive emission absorbing section formed in the guide means at a location toward the proximal end thereof relative to the helically formed distal end thereof, to shield tissue from radiation exposure; and

withdrawing the guide means from the catheter with the radiation source contained within said radioactive emission absorbing section.

35. The method as in claim 31 wherein the step of withdrawing the guide means from the patient further comprises the steps of:

retracting said guide means into a radioactive emission absorbing section formed in the distal end of said catheter such that the radiation source may be contained therein to shield tissue from radiation exposure; and

withdrawing the catheter from the patient with the guide means contained therein.

36. The method as in claim 27, wherein the step of inserting the guide means into the patient further comprises the steps of:

inserting the guide means in a straightened condition into the lumen of a catheter such that the distal end of the guide means is contained within the distal end of the catheter;

threading the catheter into the blood vessel, body cavity or the like of the patient with the guide means disposed within the catheter during said threading, such that the distal end of the catheter and the enclosed guide means is advanced to a point near the target location.

37. The method as in claim 36 wherein the step of expanding the distal end of the guide means into a helical coil comprises the step of:

advancing said guide means beyond the distal end of said catheter, whereby the guide means may be unconstrained.

38. The method as in claim 36 wherein the step of expanding the distal end of the guide means into a helical coil comprises the step of:

retracting the distal end of said catheter from around the distal end of said guide means, whereby the guide means may be unconstrained.

39. The method as in claim 36 wherein the step of withdrawing the guide means from the patient further comprises the steps of:

retracting the radiation source into a radioactive emission absorbing section formed in the guide means at a location toward the proximal end thereof relative to the helically formed distal end thereof, to shield tissue from radiation exposure; and

withdrawing the guide means from the catheter with the radiation source contained within said radioactive emission absorbing section.

40. The method as in claim 36 wherein the step of withdrawing the guide means from the patient further comprises the steps of:

retracting said guide means into a radioactive emission absorbing section formed in the distal end of said catheter such that the radiation source may be contained therein to shield tissue from radiation exposure; and

withdrawing the catheter from the patient with the guide means contained therein.