GB2428201A

GB2428201A - Tracheostomy instrument

Info

Publication number: GB2428201A
Application number: GB0613640A
Authority: GB
Inventors: Adam Tebbutt
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 2005-07-09
Filing date: 2006-07-10
Publication date: 2007-01-24
Anticipated expiration: 2026-07-10
Also published as: GB2428201B; GB0514131D0; GB0613640D0

Abstract

A tracheostomy instrument for use in a blunt dissection technique has an inner needle 1 within an outer sleeve 2 that is urged rearwardly by a spring 3. A releasable catch 17, with tooth 40 that engages in window 33, enables the needle 21 to be removed from the sleeve 2 after penetration of the trachea. The sleeve 2 has a flexible lead portion 21 extending to a tapering portion 23 at its patient end that is used to dilate the opening into the trachea after removal of the needle 1.

Description

TRACHEOSTOMY INSTRUMENTS

This invention relates to tracheostomy instruments.

In blunt dissection techniques for forming a tracheostomy, the surgeon cuts through the outer tissue of the neck overlying the trachea and uses his finger to separate underlying tissue and locate the external wall of the trachea. He then makes an incision using a needle through the wall of the trachea so that a guidewire can be introduced, followed by a dilator and the tracheostomy tube, in the usual way. During the insertion of the needle through the tracheal wall there is a relatively high risk of needle-stick injury to the surgeon because his finger has to be kept in close proximity to the site of entry of the needle.

It is an object of the present invention to provide an alternative tracheostomy instrument.

According to the present invention there is provided a tracheostomy instrument including an inner needle with a cutting tip at its forward, patient end adapted to penetrate the wall of the trachea and a manual member at its rear end, an outer sleeve extending along the length of the needle, resilient means acting between the outer sleeve and the inner needle to urge the needle rearwardly such that the cutting tip of the needle is normally concealed safely within the outer sleeve in a retracted position but can be

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displaced to an exposed position where its cutting tip is exposed beyond the forward end of the outer sleeve by displacing the manual member, and such that, when the manual member is released, the needle returns to the retracted position.

The outer sleeve preferably has a tapered portion along its length towards its patient end. The outer sleeve preferably has a lead portion of substantially constant diameter extending from its forward end to the tapered portion, a rear portion with a diameter larger than the lead portion extending rearwardly from the tapered portion. The lead portion is preferably flexible. The resilient means may be a helical spring extending axially along the needle. The needle is preferably removable from the outer sleeve. The needle may include a catch arranged to engage an edge of an aperture in the outer sleeve to limit rearward displacement of the needle relative to the sleeve, the needle being removed from the sleeve by manually releasing the catch, The needle may have a hub at its machine end with a manually-engageable pad by which the needle can be pushed axially against the action of the resilient means, the hub including a recess for receiving the nose of a syringe.

A tracheostomy instrument according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of the instrument, shown transparent, with the tip of the needle extended;

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Figure 2 is a perspective view of the rear, machine end of the instrument, shown transparent, with the tip of the needle retracted; and Figure 3 is a cross-sectional side elevation view of the rear end of the instrument in a retracted state.

The instrument comprises an inner needle assembly 1 and an outer sleeve assembly 2 in the form of a combined cannula and predilâtor within which the needle assembly is contained. A helical spring 3 within the outer sleeve assembly 2 acts to urge the needle assembly 1 rearwardly to a safe, retracted condition.

The outer sleeve assembly 2 is about 130mm long. At its forward end 20 it has a lead portion or cannula 21 of constant diameter, typically about 3mm and is made of a flexible plastics material, such as PTFE. The rear part of the cannula 21 is positioned in the bore of a predilator 22 so that a length of about 20mm projects from its forward end.

The predilator 22 is of a plastics material and is substantially rigid. It comprises a tapered forward portion 23, about 12mm long, which tapers rearwardly to an increased diameter, and a rear portion 24 of constant diameter and about 66mm long. At its rear, machine end, the predilator 22 is joined with a handle portion 25 of increased lateral dimensions.

The handle 25 is about 45mm long and of rectangular section with a hollow interior providing a recess 26 and is open at its rear end 27. The forward end of the recess 26 has

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a floor 28 through which opens the bore 29 of the predilator. The rear end 30 of the bore 29 is enlarged where it opens into the recess 26 and its forward end provides an annular step 31 where it joins the smaller diameter part of the bore. One of the lateral faces 32 of the handle 25 has a rectangular window 33 opening into the recess 26. Instruments where a cannula is integrated with a predilator are known from GB23 83756.

The needle assembly I comprises a rigid, hollow, metal needle 10 with a bevelled, pointed cutting tip 11 at its forward, patient end. At its rear, machine end 12 the needle 10 is securely joined with a hub 13 moulded from a rigid plastics material. The hub 13 has a generally rectangular section such that it is a close sliding fit within the recess 26 in the handle 25. The rear end of the hub 13 is enlarged laterally outwardly to provide a manual member in the form of an oval pad 36 shaped to receive the thumb of the user. The hub 13 has a bore 14 extending axially along its entire length within which the rear end of the needle 10 is received and secured. At its forward end, the bore 14 is enlarged in diameter to form a short cylindrical recess 15 so that there is an annular clearance around the outside of the needle 10. At its rear end, the bore 14 is also enlarged to form a rear recess 16 adapted to receive the luer tapered nose of a syringe or other device. One face of the hub 13 is formed with a catch member 17 in the form of a longitudinal spring arm attached at its rear end 18 and unattached at its forward end 19. The forward end 19 of the catch member 17 is thickened on its outer surface to form a tooth 40 with a rear-facing step 41. A space 42 beneath the catch member 17 enables its free end 19 to be pushed resiliently inwardly. The tooth 40 locates in the window 33 in the handle 25, with the step 41 engaging the rear edge 34 of the window 33 when the needle assembly 1 is in its natural state.

The spring 3 is helical and extends coaxially around the needle 10 with its rear end located in the recess 15, at the forward end of the hub 13, and its forward end located in the enlarged rear end 30 of the bore 29 in the outer sleeve assembly. The natural length of the spring 3 is such that it is held in compression between the hub 13 and the forward end of the bore 30 thereby urging the needle assembly I rearwardly relative to the sleeve assembly 2. Rearward displacement of the needle assembly 1 is limited by engagement of the step 41 against the edge 34 of the window 33. In this position, the length of the needle is such that its cutting tip 11 is located within the cannula 21, that is, it is retracted and safely concealed to prevent any risk of needle-stick injury (as shown in Figure 2).

The instrument is used in a blunt dissection tracheostomy technique. The surgeon makes an incision through surface tissue of the neck above the trachea and uses his finger to separate underlying tissue and locate the wall of the trachea. The instrument is then held in the other hand, in the safe, retracted state and its forward end is guided through the tissue until the tip 20 of the cannula 21 touches the outside of the wall of the trachea.

The surgeon then pushes with his thumb on the pad 36 to extend the needle 10 fully (to the position shown in Figure 1). He then pushes the cutting tip 11 of the instrument through the wall of the trachea. Once the trachea has been penetrated, the surgeon releases the pad 36 so that the spring 3 retracts the needle assembly 1 rearwardly to a safe position. He can then aspirate with a syringe (not shown) connected to the recess 16, to confirm correct placement in the trachea. He then removes the needle assembly 1 by pushing the tooth 40 in to clear the edge 34 of the window 33 and pulling the needle assembly out by the pad 36. The spring 3 remains in place in the sleeve assembly 2. The next step is to insert a conventional guidewire (not shown) through the sleeve assembly 2.

This is pushed through the bore 29 of the sleeve assembly 2 so that its patient end emerges into the trachea, out of the tip 20 of the cannula 21, and the rear end of the guidewire protrudes from the housing 25 of the sleeve assembly. The sleeve assembly 2 is then pushed into the trachea along the guidewire so that the tapered portion 23 dilates the opening into the trachea until the larger, rear end 24 of the assembly extends through the opening. The flexible nature of the cannula 21 ensures that it can flex to follow the guidewire. The sleeve assembly 2 is then removed, leaving the guidewire in position so that one or more further, larger dilators can be slid along the guidewire to enlarge the opening sufficient to receive a tracheostomy tube.

A tracheostomy instrument is known including a needle, spring and outer sleeve from GB2393398 but, this previous instrument is used in a different way and the spring is arranged to expose the needle rather than to retract it, as in the present arrangement.

The instrument of the present invention enables increased safety in making a tracheostomy because the cutting point of the needle can be protected right up to the time the incision is made and immediately after the incision is made. By ensuring that the needle returns automatically to the retracted, safe state when released, the risk that the needle might be left inadvertently extended is reduced, compared, for example, with a similar instrument where the needle can be locked in the extended position.

Claims

I. A tracheostomy instrument including an inner needle with a cutting tip at its forward, patient end adapted to penetrate the wall of the trachea and a manual member at its rear end, an outer sleeve extending along the length of the needle, resilient means acting between the outer sleeve and the inner needle to urge the needle rearwardly such that the cutting tip of the needle is normally concealed safely within the outer sleeve in a retracted position but can be displaced to an exposed position where its cutting tip is exposed beyond the forward end of the outer sleeve by displacing the manual member, and such that, when the manual member is released, the needle returns to the retracted position.
2. A tracheostomy instrument according to Claim 1, wherein the outer sleeve has a tapered portion along its length towards its patient end.
3. A tracheostomy instrument according to Claim 2, wherein the outer sleeve has a lead portion of substantially constant diameter extending from its forward end tci the tapered portion, and wherein a rear portion with a diameter larger than the lead portion extends rearwardly from the tapered portion.
4. A tracheostomy instrument according to Claim 3, wherein the lead portion is flexible.

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5. A tracheostomy instrument according to any one of the preceding claims, wherein the resilient means is a helical spring extending axially along the needle.
6. A tracheostomy instrument according to any one of the preceding claims, wherein the needle is removable from the outer sleeve.
7. A tracheostoniy instrument according to Claim 6, wherein the needle includes a catch arranged to engage an edge of an aperture in the outer sleeve to limit rearward displacement of the needle relative to the sleeve, and wherein the needle is removed from the outer sleeve by manually releasing the catch.
8. A tracheostomy instrument according to any one of the preceding claims, wherein the needle has a hub at its machine end with a manuallyengageable pad by which the needle can be pushed axially against the action of the resilient means, and wherein the hub includes a recess for receiving the nose of a syringe.
9. A tracheostomy instrument substantially as hereinbefore described with reference to the accompanying drawings.
10. Any novel and inventive feature or combination of features as hereinbefore described.