Echogenic medical device

• US 6,723,052 B2
• Filed: 06/07/2001
• Issued: 04/20/2004
• Est. Priority Date: 06/07/2001
• Status: Expired due to Term

• Current Assignee: Cowles Ventures LLC
• Original Assignee: Mills Biopharmaceuticals, Inc.
• Inventors: Mills, Stanley L.
• Primary Examiner(s): Ruhl, Dennis W.
• Assistant Examiner(s): Jung, William C
• Application Number:
  US09/878,159
• Publication Number:
  US 20020188195A1
• Time in Patent Office: 1,048 Days
• Field of Search: 600/437-472, 600/420, 600/309, 600/1-15, 604/100.01
• US Class Current: 600/459
• CPC Class Codes: A61B 2090/3925 ultrasonic
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures

Abstract

Echogenic medical devices, methods of fabrication and methods of use are disclosed. The device can be adapted to be inserted into a patient. The echogenic construction can be incorporated into the device at the time of fabrication providing acoustic impedance different from that of the surrounding biological tissue or fluid. The medical device is designed for use with an ultrasound imaging system to provide real-time location of the insertion and guidance at the time the device is implanted in a patient, such as in brachytherapy. Following placement of the device the position can be evaluated over time to insure the device remains in proper aligmnent and functional. Furthermore, the device is designed to incorporate a spacer element at one or both ends to provide separation between radioactive elements.

Claims

1. A medical device comprising:

a parabolic surface defining a body chamber, the body chamber including polymer; and

a radiosiotopic component inside the body chamber, the medical device having a proximal and a distal end, and the medical device being adapted for implantation into a live body.

2. The device of claim 1, where the radioisotopic component comprises ²⁶Al, ¹⁹⁸Au, ¹¹⁵Cd, ¹³⁷Cs, ¹²⁵I, ¹⁹²Ir, ⁴⁰K, ³²P, ¹⁰³Pd, ⁸⁶Rb, ¹²³Sn, ⁸⁹Sr, ⁹⁰Sr, ¹²⁵Te ⁹⁰Y, ⁹¹Y, ¹⁶⁹Yb or a combination of these.

3. The device of claim 2, where the radioisotopic component comprises ¹²⁵I or ¹⁰³Pd.

4. The device of claim 1, where the device comprise at least one spacer element connected to the body chamber.

5. The device of claim 4, further comprising a plurality of spacer elements.

6. The device of claim 5, comprising at least one spacer element at the proximal end and at least one spacer element at the distal end of the device.

7. The device of claim 4, comprising at least one spacer element at the proximal end of the device.

8. The device of claim 4, comprising at least one spacer element at the distal end of the device.

9. The device of claim 4, further comprising a plurality of parabolic surfaces, each parabolic surface defining a body chamber, each body chamber including polymer.

10. The device of claim 9, where one body chamber is connected to a spacer element that is connected to at least a second body chamber.

11. The device of claim 4, the spacer element further comprising a contrast material.

12. The device of claim 11, where the contrast material is silver, gold, or tungsten.

13. The device of claim 11, where the contrast material is adapted for nuclear magnetic imaging.

14. The device of claim 11, where the contrast material is adapted for radiographic imaging.

15. The device of claim 4, further comprising a docking guide operatively attached to the spacer element or to the body chamber, and the docking guide is at the proximal end of the device.

16. The device of claim 15, where the docking guide is configured to accept a radioactive source or a spacer.

17. The device of claim 15, where the docking guide comprises a flexible joint.

18. The device of claim 15, where the docking guide comprises a non-locking docking port.

19. The device of claim 4, where the device is adapted to monitor the positioning of the radioisotopic component in a patient.

20. The device of claim 1, further comprising a contrast material inside the body chamber.

21. The device of claim 1, where the device has a density of between 0.5 and 1.5 g/ml.

22. The device of claim 1, where the device has a density of between 0.8 and 1.2 g/ml.

23. The device of claim 1, where the device has a density of between 0.9 and 1.1 g/ml.

24. The device of claim 1, where the polymer comprises one or more synthetic polymers.

25. The device of claim 1, where the polymer is selected from the group consisting of liquid crystal polymer (LCP), Teflon, carboxylic polymers, polyacetates, polyacrylics, polyacrylamides, polyamides, polyvinylbutyrals, polycarbonates, polyethylenes, polysilanes, polyureas, polyurethanes, polyethers, polyesters, polyoxides, polystyrenes, polysulfides, polysulfones, polysulfonides, polyvinylhalides, pyrrolidones, rubbers, and thermal-setting polymers.

26. The device of claim 25, where the polymer is LCP.

27. The device of claim 26, where the LCP is an extruded LCP.

28. The device of claim 1, further comprising one or more voids, bubbles or channels.

29. The device of claim 28, where each void is between 0.01 mm and 0.9 mm in length.

30. The device of claim 29, where each void is about 0.5 mm in length.

31. The device of claim 29, comprising 1-10 voids.

32. The device of claim 31, comprising 1 void.

33. The device of claim 28, where each bubble is between 0.001 and 0.1 mm in diameter.

34. The device of claim 33, where each bubble is about 0.01 mm in diameter.

35. The device of claim 28, where each channel is between 0.001 and 0.1 mm in diameter.

36. The device of claim 35, where each channel is about 0.01 mm in diameter.

37. The device of claim 35, where each channel spirals at approximately 45°

C. to the long axis.

38. The device of claim 1, where the device is adapted for use in brachytherapy.

39. A method of manufacturing an ultrasonically visible device, the method comprising:

(a) obtaining a liquid crystal polymer (LCP) tube comprising a proximal and a distal end;

(b) obtaining a LCP spacer element;

(c) placing the spacer element in the proximal end of the LCP tube;

(d) sealing the proximal end of the LCP tube containing the spacer element; and

(e) sealing the distal end of the LCP tube, forming a body chamber, where the inner surface of the body chamber is a parabolic surface.

40. The method of claim 39, further comprising the step:

(f) shaping the body chamber by heating the body chamber to form hemispherical repeating units on the body chamber.

41. The method of claim 40, where the heating is ultrasonic heating.

42. The method of claim 40, where step (f) occurs before steps (c), (d) or (e).

43. The method of claim 39, where the spacer comprises a contrast agent.

44. The method of claim 43, where the contrast agent is silver, gold or tungsten

45. The method of claim 39, further comprising a second spacer element.

46. A method of manufacturing an ultrasonically visible device, the method comprising:

(a) obtaining a liquid crystal polymer (LCP) tube comprising a proximal and a distal end;

(b) sealing the proximal end of the LCP tube;

(c) placing a radioisotopic component into the LCP tube; and

(d) sealing the distal end of the LCP tube, forming a body chamber containing the radioisotopic component, where the surface of the body chamber is a parabolic surface.

47. The method of claim 46, further comprising the step:

(e) shaping the body chamber by heating the body chamber to form hemispherical repeating units on the body chamber.

48. The method of claim 48, where the heating is ultrasonic heating.

49. The method of claim 48, where step (e) occurs before steps (b), (c) or (d).

50. A method of monitoring implant position in a position in a partial comprising:

(a) inserting a medical device into the patient, the device comprising a parabolic surface defining a body chamber and a radioisotope component incorporated into the device;

(b) directing an ultrasonic beam at the implant position;

(c) reflecting a signal from the ultrasonic beam off of the parabolic surface;

(d) collecting the reflected ultrasonic signal; and

(e) determining the location of the device in the patient from the reflected ultrasonic signal.

51. The method of claim 50, further comprising surgically extracting tissue from the patient.

52. The method of claim 51, where the location is determined after extraction of tissue from the patient.

53. The method of claim 50, where the medical device further comprises a nuclear magnetic or radiographic contrast agent.

54. The method of claim 50, where the device is a brachytherapy.

55. The method of claim 50, where more than one of the devices is inserted in the patient.

56. The method of claim 50, where the device is used for breast lesion localization.

57. The method of claim 50, where the location is determined before an operation.