WO2011079168A1

WO2011079168A1 - Plugless brachytherapy needle

Info

Publication number: WO2011079168A1
Application number: PCT/US2010/061712
Authority: WO
Inventors: Jay Reed; Kevin Helle
Original assignee: Medi-Physics, Inc.
Priority date: 2009-12-23
Filing date: 2010-12-22
Publication date: 2011-06-30

Abstract

A plugless brachytherapy needle includes either a detent span defined between a pair of elongate channels formed in the needle wall such that the detent span is deflected into the needle passageway or a pair of detent tongs deflected into a single transverse opening towards the needle passageway.

Description

PLUGLESS BRACHYTHERAPY NEEDLE

Field of the Invention

The present invention is directed to the field of brachytherapy equipment. More specifically, the present invention relates to a brachytherapy needle which does not require a plug at its dispense end.

Background of the Invention

The prior art has seen various attempts at holding a brachytherapy member, whether an elongate brachytherapy strand or a number of loose brachytherapy seeds and/or spacers, within an implantation needle. For example, it has been known to dip the dispense end of the needle into a wax which then solidifies to hold the brachytherapy member in place during transportation or handling yet yields to let the member pass once the member is acted upon by a stylet during implantation. Alternatively, the needle may be plugged with a sterile elastomeric material or with a sterilized cat-gut material. Each perform essentially the same function as they are able to hold the brachytherapy member in place during routine transportation and handling environments, but will give way as the brachytherapy member is urged out of the needle by a stylet. In each of these examples, the plug material is dispensed into the patient with the brachytherapy member.

With reference to Figure 1, United States Patent No. 6,450,938 to Miller discloses a plugless brachytherapy needle 2 having deflectable tong 4 at the dispense end 5 thereof. The tong is a cantilevered piece whose free end is deflected into the needle passageway. The free end of the tong extends towards the dispense end of the needle. In transverse facing opposition to the free end of the tong is an exposed edge 8 of the cut-out that can grab tissue and force the tissue towards the depressed tong, resulting in trauma to the tissue as the needle is withdrawn from the tissue. United States Patent No. 7,150,790 to Schmidt et al. discloses a plugless brachytherapy needle having dimple formed at the dispense end of the needle. While obviating the trauma from an exposed transverse edge of a cut-out, such a design requires deformation of the needle without stress-relief for the tubular wall. As such, the penetration of the dimple into the needle passageway is difficult to ensure for mass- production.

There is therefore a need in the art for a plugless brachytherapy needle which reduces patient trauma during both needle insertion and withdrawal. Such a needle would ideally provide the ease and predictable manufacturing of the Miller needle with the low trauma of the Schmidt needle.

Summary of the Invention

In view of the needs of the prior art, the present invention provides a plugless brachytherapy needle which reduces patient trauma as the needle is either inserted into or withdrawn from a patient. The needle includes an elongate needle body having an elongate tubular wall defining an elongate needle passageway. At least one transversely- opening aperture is formed in the needle body to be in fluid communication with the passageway so as to form either a single detent span or a pair of longitudinally-opposed detent tongs. The detent span, and the detent tongs, are deflected towards said passageway so as to provide opposed tapering surfaces descending into the aperture. The detent span, or one of the detent tongs, is deflected towards the needle passageway far enough so as to engage restrict passage of an elongate brachytherapy member therepast. The needles of the present invention reduce the aperture edges which can catch tissue as the needle is inserted into or withdrawn from the patient.

Brief Description of the Drawings

Figure 1 depicts a plugless brachytherapy needle of the prior art.

Figure 2 depicts a plugless brachytherapy needle of the present invention. Figure 3 depicts a cross-sectional view of the needle of Figure 2 holding a train of loose seeds and spacers therein.

Figure 4 depicts a cross-sectional view of the needle of Figure 2 holding a brachytherapy strand therein.

Figure 5 depicts a close-up view of the depressed bridge of the needle of the present invention. Figure 6 depicts a close-up view of an alternative detent for a plugless brachytherapy needle of the present invention.

Figure 7 depicts a cross-sectional view of the plugless brachytherapy needle of Figure 6.

Figure 8 depicts yet another embodiment of a plugless brachytherapy needle of the present invention.

Figure 9 depicts a cross-sectional view of a plugless brachytherapy needle of the present invention showing a brachytherapy member in the storage, or transportation, position.

Figure 10 depicts a cross-sectional view of a plugless brachytherapy needle of Figure 9, showing a brachytherapy member in a dispense position.

Figure 11 depicts a cross-sectional view of a plugless brachytherapy needle of the present invention showing a brachytherapy member in the storage, or transportation, position. Figure 12 depicts a cross-sectional view of a plugless brachytherapy needle of

Figure 11, showing a brachytherapy member in a dispense position. Figure 13 depicts a method for forming a plugless brachytherapy needle of the present invention.

Detailed Description of the Preferred Embodiment

With reference to Figures 2 and 5, the present invention provides a plugless needle 10. Needle 10 eliminates the need for incorporating a plug for holding a brachytherapy member therein. The conventional brachytherapy member may take the form of a brachytherapy strand or a train of brachytherapy seeds and/or spacers. Needle 10 is formed from conventional material for brachytherapy needles, such as stainless steel and is of a gage that is useful for brachytherapy procedures, such as 18 gage or 20 gage.

Needle 10 includes an elongate needle body 12 spanning between a sharpened first end 14 and an opposed second end 16. Second end 16 typically supports a luer connector 18 or some other connection member useful for brachytherapy procedures. First end 14 defines a dispense aperture 20, second end 16 defines a stylet aperture 22, and needle body 12 defines an elongate needle passageway 24 extending in fluid communication therebetween. An elongate stylet 26 includes a tip 28 which is inserted through stylet aperture 22 into passageway 24. Tip 28 of stylet 26 operates on the brachytherapy load 30, shown in Figure 3 to be a train 34 of loose brachytherapy seeds 36 and, optionally, spacers 38 and shown in Figure 3 to be an elongate brachytherapy strand 32, to force the load 30 out of needle 10 through dispense aperture 20.

Proximate to first end 14, needle body 12 defines adjacent first and second elongate apertures 40 and 42. Apertures 40 and 42 are separated by an elongate detent span 44. Detent span 44 is deflected towards passageway 24 a sufficient distance so as to be able to engage and releasably hold a brachytherapy load aft from dispense aperture 20. By "releasably hold", the present invention intends that detent span 44 sufficiently extends into passageway 24 so as to prevent a brachytherapy load 30 from being able to mover therepast simply by the gravitational or intertial forces exterted by the brachytherapy load 30. However, upon application of additional dispense force by stylet 26, the brachytherapy load 30 will be able to slide past detent span 44 and out from passageway 24 through dispense aperture 20. As seen in Figure 5, apertures 40 and 42 are defined between longitudinally- opposed pairs of edges 40a, 40b and 42a, 42b, respectively. Edges 40a, 40b and 42a, 42b thus provide smaller tissue-cutting surfaces in both directions of needle travel as compared to, e.g., needle 2 of Figure 1. As body tissue conforms about needle 10, the outer surface 44a of detent 44 provides a smoother deflection of the tissue which helps minimize insult by the edges which define apertures 40 and 42. Needle 10 thus reduces patient trauma as compared to known brachytherapy needles with detents.

It is further contemplated by the present invention that apertures 40 and 42 need not be parallel openings in the needle body 12. As shown in Figure 8, apertures 40' and 42' have opposed crescent shapes. Detent span 44' is thus defined having non-parallel edge surfaces 45a and 45b so that detent span 44' is wider mid-span than at its opposed longitudinal ends. It is further contemplated (though not shown) that apertures 40' and 42' may be to opposite sides of detent span 44' than as shown, so that span 44 is thinner mid-span than at its opposed longitudinal ends.

In an alternative embodiment of the present invention, shown in Figures 6 and 7, a brachytherapy needle 110 is provided. Like numbering is to reflect like components as for needle 10. Needle 110 is desirably similar to needle 10 in all manner except that, in place of apertures 40 and 42 and detent span 44 of needle 10, needle 110 includes an elongate cylindrical needle body 112 which defines a single transversely-opening aperture 150 and opposing detent tongs 152 and 154 projecting into aperture 150. Detent tong 152 is deflected further into passageway 124 than detent tong 154, so that detent tong 152 will hold a brachytherapy member within passageway 24 against gravitational or inertial forces, but will allow brachytherapy member 52 to be dispensed through first end 14 under the urging of a stylet. Desirably, detent tong 154 will provide no resistance to the brachytherapy member 52 during any phase of storage, transportation, handling, or dispensement.

Aperture 150 includes pairs of adjacent edges 150a, 150b and 150c, 150d to either side of detent tongs 152 and 154 respectively. Detent tongs 152 and 154 each include an outer surface 152a and 154a, respectively, which are tapered with respect to the needle longitudinal axis X. Needle 110 thus reduces insult to body tissue as it conforms threreabout because tapering surfaces 152a and 154a help gently carry tissue past adjacent edges 150a and 150b during needle insertion into, and past adjacent edges 150c and 150d during needle withdrawal from, the patient.

Referring now to Figures 9-12, a needle 210 of the present invention includes a detent span 244 having an apex 245 at a known geometry so that the location of a seed abutting to either side of the detent 244 is thereby known. The apex 245 of detent span 244 is defined as that point or length of the detent span which is capable of retaining the widest portion of the brachytherapy member within passageway 222. Thus, a physician will thus know where the seed is with respect to the needle tip by the tactile sense of pushing on the brachytherapy member 30 with the stylet. The needle is desirably provided to the physician with the brachytherapy member 30 loaded therein, although the present invention further contemplates that a physician may direct the loading of brachytherapy member 30 into needle 210. The physician, upon pushing on the stylet will sense the interference provided by the detent 244 against the first seed 36 in the train. The physician will therefore know that the seed is on the proximal side of the detent (ie, towards the physician from the detent span). Upon further urging, the stylet will force the first seed 36 of brachytherapy member 30 past the apex 245 of the detent span 244. The physician will feel the resistance give way and know that the seed 36 is now on the distal, or opposite, side of apex 245 of detent 244, desirably with one end of the brachytherapy member being coextensive with the needle tip. As the location of the apex is known, the physician will also know where the brachytherapy seed is with respect to the needle, thereby providing greater certainty to the placement of the seed at the spot called for by the treatment plan. As shown in Figures 9-12, the detent 244 may be positioned further from the needle tip 211. In Figures 9 and 10 the apex 245 of the detent span 244 is positioned the combined length of one brachytherapy seed and one space further from needle tip 211, whereas in Figures 11 and 12 the detent span 244 is positioned the combined length of two brachytherapy seeds and two spacers further from needle tip 211. With a standard brachytherapy member 30, the length of the seed and spacer in combination is known, typically as one centimeter. Physicians will thus know for needle 210 of Figures 9-12, upon sensing the clearance of the widest part of the brachytherapy member 30, in this case the seed 36 past the apex 245 of the detent span 244, the location of the lead seed with respect to the needle tip 211. Therefore, by knowing the distal separation of the apex of the detent span from the tip of the needle as well as the length of the seeds and spacers of the brachytherapy member, the physician will be able to more precisely locate the seeds according to the dose plan for the patient. The detent may be located close to the needle tip so as to secure the first seed, as shown in Figures 9 and 10. Alternatively, the detent may be located so as to hold the second seed in a storage position aft of the needle tip, as shown in Figures 11 and 12. The present invention further contemplates that the detent may be anywhere along the needle so as to hold at least one seed aft thereof with respect to the needle tip, although with variable loads other seed placement may not be a particular distance away from the first seed.

Referring now to Figure 13, the manufacture of the present invention is contemplated to include the step of laser etching the required aperture or apertures in the needle body. A two-piece negative form 200, having elongate anvil components 202 and 204, is employed to ensure proper deformation of the formed detent span or detent tongs. Anvil components 202 and 204 are inserted through opposing ends of the needle so that the tips 202a and 204a, respectively, meet in underlying registration with the formed aperture. Tips 202a and 204a provide a negative for the final positioning of the span or tongs. An external force is then applied by tool 206 to force the span or tongs to conform to the profiles provided by tips 202a and 204a. Once the span or tongs are properly deflected, anvil components 202 and 204 may then be withdrawn back out the opposed ends of the needle, respectively.

While the particular embodiment of the present invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teachings of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.

Claims

What is Claimed Is:

1. A plugless needle for delivering fluid comprising

an elongate needle body having an elongate tubular wall defining opposed first and second open ends and defining an elongate needle passageway extending therebetween, said tubular wall defining a first and second transversely-spaced elongate channels to define an elongate detent span therebetween, the central portion of said detent span being deflected towards the needle passageway so as to restrict passage of an elongate brachytherapy member therepast.

2. A plugless needle of claim 1, wherein said first and second channels are located proximate the first open end of said needle body.

3. A plugless needle of claim 2, further comprising a hub at said second open end of said needle body, wherein said hub supports at least one pair of luer fittings thereon.

4. A plugless needle of claim 1, having a cross-sectional dimension of a 16 gauge needle.

5. A plugless needle of claim 1, having a cross-sectional dimension less than a 16 gauge needle.

6. A pluglesss needle of claim 1, having a cross-sectional dimension of a 20 guage needle.

7. A plugless needle of claim 1, wherein the spacing of the apex of the detent span from the needle tip is known.

8. A plugless needle of claim 7, wherein the dimensions of any seeds and spacers comprising the brachytherapy member are known.

9. A plugless needle for delivering fluid comprising

10. A plugless needle of claim 9, wherein said first and second channels are located proximate the first open end of said needle body.

11. A plugless needle of claim 9, further comprising a hub at said second open end of said needle body, wherein said hub supports at least one pair of luer fittings thereon.

12. A plugless needle of claim 9, having a cross-sectional dimension of a 16 gauge needle.

13. A plugless needle of claim 9, having a cross-sectional dimension less than a 16 gauge needle.

14. A pluglesss needle of claim 9, having a cross-sectional dimension of a 20 guage needle.

15. A method of forming a plugless brachytherapy needle, comprising the steps of:

Providing an elongate brachytherapy needle having an elongate tubular needle body defining opposed first and second ends and an elongate needle passageway in fluid communication therebetween;

Forming a transversely-opening aperture in the needle body in fluid

communication with said needle passageway, said aperture being further defined by opposed first and second longitudinally-extending elongate detent tongs; and

Deflecting said first and second detent tongs towards said passageway.

16. A method of claim 15, further comprising the step of deflecting the first detent tong further into said passageway than said second detent tong.

17. A method of claim 15, further comprising the steps of:

Proving first and second anvil components, each said anvil component comprising a tip having a negative form for the deflected detent prongs, through opposed open ends of said needle body; Positioning the tips of said anvil components in underlying registry with said transversely-opening aperture; and

Removing said anvil components after said deflecting step.

18. A method of forming a plugless brachytherapy needle, comprising the steps of:

Forming first and second transversely-opening apertures in the needle body in fluid communication with said needle passageway, said aperture being further defined to either side of an elongate detent span; and

Deflecting said first and second detent tongs towards said passageway.

19. A method of claim 18, wherein said first and second apertures are crescent- shaped.

20. A method of claim 18, further comprising the steps of:

Proving first and second anvil components, each said anvil component comprising a tip having a negative form for the deflected detent span, through opposed open ends of said needle body;

Positioning the tips of said anvil components in underlying registry with said transversely-opening apertures; and

Removing said anvil components after said deflecting step.