Pre-loaded needle assembly

• US 20020049411A1
• Filed: 10/24/2001
• Published: 04/25/2002
• Est. Priority Date: 10/25/2000
• Status: Active Grant

• Current Assignee: Theragenics Corporation (Juniper Investment Co. LLC)
• Original Assignee: Gary A. Lamoureux, Richard A. Terwilliger
• Inventors: Terwilliger, Richard A., Lamoureux, Gary A.
• Granted Patent: US 6,554,760 B2
• Time in Patent Office: Days
• US Class Current: 604/164.01
• CPC Class Codes: A61N 2005/1011 Apparatus for permanent insertion of sources
• CPC Class Codes: A61N 2005/1023 Means for creating a row of seeds, e.g. spacers
• CPC Class Codes: A61N 5/1027 Interstitial radiation therapy

Abstract

For implanting a therapeutic element, this needle assembly comprises a cannula having a sharpened distal end, a line of elements in the cannula extending rearward from the distal end. yieldable positioner positions the element more proximate the distal end a predetermined distance from the distal end. The positioner may be in various forms including an end plug, a tab in the cannula and a distortion of the wall of the cannula. A stylet is reciprocable in the cannula and engages the end of the line of elements more remote from the distal end of the cannula.

Claims

1. For implanting a therapeutic element, a needle assembly comprising a cannula having a sharpened distal end, a line of elements in the cannula extending rearward from the distal end, yieldable means for positioning the element more proximate the distal end a predetermined distance from the distal end, and a stylet reciprocable in the cannula engaging the end of the line of elements more remote from the distal end of the cannula.

2. A needle assembly as claimed in claim 1 wherein the means for positioning is a plug.

3. An assembly as claimed in claim 1 wherein the line of seeds is encapsulated, the seeds being held in spaced relation by the encapsulation.

5. An assembly as claimed in claim 1 wherein the wall of the distal end of the cannula is formed with an irregularity to comprise the means for positioning.

6. An assembly as claimed in claim 1 wherein the wall is longitudinally slitted at peripherally spaced location and the wall is deflected inward between two adjacent slits to form an inward tabs to comprise the means for positioning.

7. An assembly as claimed in claim 6 wherein the inward tab extends inward from the wall of the cannula and has a U-shaped outline.

8. An assembly as claimed in claim 6 wherein the irregularity is an inward hump in the wall of the cannula between the slits.

4. An assembly as claimed in claim I wherein the line of seeds has a rearward tail and the distal end of the stylet is formed with an axial recess receiving the tail.

9. For implanting a therapeutic element, a needle assembly comprising a cannula having a sharpened distal end, a generally cylindrical end plug frictionally held in the distal end having its rearward end extending from the distal end a pre-determined distance, a line of seeds in the cannula contacting the plug and extending rearward therefrom, and a stylet reciprocable in the cannula engaging the end of the line of seeds more remote from the distal end of the cannula.

10. An assembly as claimed in claim 9 wherein the line of elements is encapsulated, the seeds being held in spaced relation by the encapsulation.

11. An assembly as claimed in claim 9 wherein the line of elements has a rearward tail and the distal end of the stylet is formed with an axial recess receiving the tail.

12. An assembly as claimed in claim 9 wherein the wall of the distal end of the cannula is formed with an irregularity to enhance the frictional holding of the plug.

13. An assembly as claimed in claim 12 wherein the irregularity is in the form of a tab extending inward of the wall.

14. An assembly as claimed in claim 12 wherein the wall is formed with peripherally spaced openings and an inward hump is deflected inward between the openings to comprise the irregularity.

15. An assembly as claimed in claim 9 wherein the stylet is formed with an axial vent.

18. A method as claimed in claim 17 wherein the diameter is modified by heating.

19. A method as claimed in claim 17 wherein the diameter of the plug is modified by treating the plug with a solvent.

20. A method as claimed in claim 17 wherein the diameter of the plug is modified by mechanical distortion.

16. A method of making a needle assembly for implanting radiation seeds, comprising the steps of:

a. providing a cannula having a sharpened distal end and a generally cylindrical plug,

b. forcing the plug into the distal end of the cannula to frictionally reside there.

17. A method of making a needle assembly for implanting therapeutic elements, comprising the steps of:

a. providing a cannula having a sharpened distal end and a generally cylindrical plug,

b. placing the plug into the distal end of the cannula to reside there, and

c. modifying the diameter of the plug to enhance its frictional engagement with the contiguous wall of the cannula.