Needle for implanting brachytherapy seeds

• US 6,450,937 B1
• Filed: 12/17/1999
• Issued: 09/17/2002
• Est. Priority Date: 12/17/1999
• Status: Expired due to Term

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Mercereau, Steven F., Jacobs, Charles
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): Veniaminov, Nikita R
• Application Number:
  US09/466,507
• Time in Patent Office: 1,005 Days
• Field of Search: 600/1-8, 604/264-266, 604/890.1, 604/891.1, 604/272, 604/110
• US Class Current: 600/7
• CPC Class Codes: A61M 37/0069 Devices for implanting pellets, e.g. markers or solid medicaments for introducing of radioactive sources for interstitial radiation therapy, i.e. brachytherapy A61N5/1027
• CPC Class Codes: A61N 2005/1011 Apparatus for permanent insertion of sources
• CPC Class Codes: A61N 5/1007 Arrangements or means for the introduction of sources into the body
• CPC Class Codes: A61N 5/1027 Interstitial radiation therapy

Abstract

A brachytherapy needle for delivering radioactive seeds into the body of a patient comprises a tube into which the radioactive seeds and intervening spacers are loaded. The tube is telescopically disposed within a cutting cannula and is substantially longer than the cannula such that the cannula can be withdrawn over the tube, leaving the forward end of the tube exposed within the tissues of the patient. When the cannula is retracted, the seeds within the tube can be visualized using conventional medical imaging technology. The tube of the disclosed embodiment includes a deformable constriction which normally retains the seeds within the lumen of the needle but which deforms to permit the seeds to pass when subjected to a predetermined force. The tube of the disclosed needle has a low-friction exterior surface to prevent tissue from being displaced as the device is withdrawn. In yet another aspect the cannula and telescoping hollow tube are dimensioned such that when the cannula is withdrawn with respect to the tube, the blunt forward edge of the tube extends beyond the cutting edge of the hollow cannula to prevent accidental needle sticks.

Claims

1. A needle for implanting seeds within the body of a patient, comprising:

a hollow cannula having a forward end and a length;

a hollow tube having at least a portion thereof comprised of a transparent material, said hollow tube being telescopically received within said hollow cannula, and said hollow tube having a length greater than said length of said hollow cannula, such that when said hollow cannula is telescopically retracted with respect to said hollow tube, a forward portion of said hollow tube extends beyond said forward end of said hollow cannula; and

a stylet telescopically received within said hollow tube;

whereby when seeds and associated spacers are loaded into said tube, proper loading of said seeds and spacers can be visually verified through said portion of said tube which is comprised of said transparent material.

2. The needle of claim 1, wherein said entire tube is comprised of a transparent material.

3. The needle of claim 1, wherein said hollow tube is comprised of a transparent thermoplastic material.

4. The needle of claim 1, wherein said hollow tube is comprised of a lubricious material.

5. The needle of claim 1, wherein said hollow tube further comprises:

an exterior surface, and

a lubricious coating on said exterior surface of said hollow tube.

6. The needle of claim 1, wherein said hollow cannula has a cutting edge at a forward end thereof, wherein said hollow tube has a blunt forward end, and wherein said cannula and tube are dimensioned such that when said cannula is withdrawn with respect to said tube, said blunt forward end of said tube extends beyond said cutting edge of said hollow cannula, thereby preventing accidental needle sticks.

7. The needle of claim 1, wherein at least said forward portion of said hollow tube is comprised of a material which is transparent to ultrasound.

8. The needle of claim 7,

wherein said forward portion of said hollow tube is of sufficient length to contain said seeds and spacers therewithin such that when said hollow cannula is retracted with respect to said hollow tube and said forward portion of said hollow tube extends beyond said forward end of said hollow cannula, said seeds and spacers are disposed beyond said forward end of said hollow cannula,

whereby when said hollow cannula the location of said seeds can be confirmed by ultrasound.

9. A needle for implanting seeds within the body of a patient, comprising:

a hollow cannula;

a hollow tube having a forward end, said hollow tube being telescopically received within said hollow cannula, and said hollow tube comprising a portion of reduced inner diameter adjacent said forward end, whereby when radioactive seeds and associated spacers are loaded into said tube, said portion of reduced inner diameter prevents said seeds from falling out of said forward end of said tube; and

a stylet telescopically received within said hollow tube.

10. The needle of claim 9, wherein said portion of reduced inner diameter of said hollow tube comprises an inwardly projecting circumferential lip at said forward end, whereby when radioactive seeds and associated spacers are loaded into said tube, said lip prevents said seeds from falling out of said forward end of said tube.

11. The needle of claim 9, wherein said portion of reduced inner diameter of said hollow tube comprises a inwardly projecting circumferential lip adjacent said forward end, whereby when radioactive seeds and associated spacers are loaded into said tube, said lip prevents said seeds from falling out of said forward end of said tube.

12. The needle of claim 9, further comprising a lubricious coating material disposed on an exterior surface of said hollow tube, and wherein said portion of reduced inner diameter of said hollow tube comprises an accumulation of said coating material on the inner surface of said hollow tube adjacent said forward end thereof, said accumulation of coating material being sufficient to reduce the inner diameter of said hollow tube so as to prevent radioactive seeds within said tube from falling out of said forward end of said tube under force of gravity.

13. The needle of claim 12, wherein said accumulation of coating material forms a membrane which closes off said forward end of said hollow tube.

14. A needle for implanting seeds within the body of a patient, comprising:

a hollow tube; and

a stylet telescopically received within said hollow tube;

said hollow tube having a lumen dimensioned to receive radioactive seeds therewithin, and said hollow tube having a constriction at a forward end thereof to prevent said radioactive seeds from exiting said forward end of said tube under force of gravity, and said constriction being deformable under a force in excess of said force of gravity to permit said seeds to pass.

15. The needle of claim 14, further comprising a hollow cannula, said hollow tube being telescopically received within said hollow cannula.

16. The needle of claim 14, wherein said constriction comprises an inwardly projecting lip.

17. The needle of claim 14, wherein said constriction is formed integrally with said hollow tube.

18. The needle of claim 14, wherein said hollow tube is comprised of a flexible thermoplastic material.

19. The needle of claim 14, wherein said hollow tube further comprises an outer surface and a lubricious coating on said outer surface.

20. A needle for implanting radioactive seeds within the body of a patient, comprising:

a hollow cannula;

a hollow tube having a lubricious exterior surface, said hollow tube being telescopically received within said hollow cannula; and

a stylet telescopically received within said hollow tube;

whereby when seeds and associated spacers are loaded into said hollow tube, said tube is introduced into a patient, and said tube is withdrawn while said stylet is held steady to push said seeds out into the tissues of said patient, said lubricious coating reduces friction between said tube and the tissues of said patient to minimize displacement of said tissues.

21. A needle for implanting radioactive seeds within the body of a patient, comprising:

a hollow cannula having a cutting forward edge; and

a hollow tube having a blunt forward edge, said hollow tube being telescopically received within said hollow cannula;

said cannula and tube being dimensioned such that when said cannula is withdrawn with respect to said tube, said blunt forward edge of said tube extends beyond said cutting edge of said hollow cannula, thereby preventing accidental needle sticks.

22. The needle of claim 21, further comprising a stylet telescopically disposed within said hollow tube.

23. A needle for implanting seeds within the body of a patient, comprising:

a hollow cannula having an exterior surface, a forward end, and a cutting edge at said forward end;

a stylet telescopically received within said hollow tube; and

a lubricious coating material disposed on said exterior surface of said cannula and within said forward end of said hollow cannula in an amount sufficient to reduce the internal diameter of said cannula adjacent said forward end such that a seed disposed within said cannula cannot fall out of said forward end of said cannula under force of gravity.

24. The needle of claim 23, wherein said lubricious coating within said forward end of said hollow cannula closes off said forward end of said cannula.