WO2006087512A1

WO2006087512A1 - Medico-surgical apparatus

Info

Publication number: WO2006087512A1
Application number: PCT/GB2006/000258
Authority: WO
Inventors: Adam Tebbutt
Original assignee: Smiths Group Plc
Priority date: 2005-02-15
Filing date: 2006-01-26
Publication date: 2006-08-24
Also published as: WO2006087512A8; GB0503082D0

Abstract

The forward, tapered end (24) of a dilator (2) projects from the patient end (10) of a tracheostomy tube (1) and its rear end projects from the rear end (11) of the tube, forming a handle (20). The forward end of the dilator has a collar (26), which extends rearwardly and overlaps the forward end (10) of the tube (1) to form a smooth continuation with the tube. The forward end portion (12) of the tube is tapered. The assembly of dilator (2) and tube (1) is inserted to the trachea (3) along a guidewire (64). The collar (26) of the dilator (2) everts forwardly when the dilator is pulled rearwardly so that it can be slid out of the tube (1), which is left in place in the trachea.

Description

MEDICO-SURGICAL APPARATUS

This invention relates to medico-surgical apparatus of the kind comprising a tube and a dilator.

The invention is more particularly concerned with apparatus for use in expanding an opening through tissue and inserting a tube into the opening, such as during a tracheostomy procedure.

There are various ways in which a tracheostomy can be carried out. In the Seldinger technique, a needle is inserted through the neck tissue to make a passage into the trachea. A wire is inserted through the needle into the trachea so that the needle can be removed and a tapered dilator or series of dilators can be slid along the wire to enlarge the opening. When the opening is wide enough, the dilator is removed and a tracheostomy tube on an introducer is slid along the wire into the trachea. The number of different steps and items of apparatus required make this a relatively complex and lengthy procedure. Since these forms of tracheostomy are often carried out in emergency situations under stress, it would be preferable for the apparatus and procedure to be simplified as much as possible. There are other surgical situations where openings need to be formed to insert a tube.

It is an object of the present invention to provide alternative medico-surgical apparatus.

According to one aspect of the present invention there is provided medico-surgical apparatus of the above-specified kind, characterised in that the tube is assembled on the dilator with the dilator extending along the bore of the tube and projecting from its patient end to provide a tapering leading end to the apparatus, that the external surface of the dilator is arranged to provide a smooth continuation with the external surface of the forward end of the tube, and that the dilator is arranged such that it can be withdrawn rearwardly through the bore of the tube. The smooth continuation is preferably provided by a flexible portion of the dilator overlapping the forward end of the tube. The flexible portion of the dilator may be a collar that can be everted when the dilator is pulled rearwardly with respect to the tube to enable the collar to pass through the tube. The external surface of the tube is preferably tapered. The tube may have an elastic sealing cuff adapted to seal with a body cavity when inflated and to lie close to the tube surface when deflated. The apparatus may include an elongate flexible member extending along a bore through the dilator and projecting from both ends of the dilator. The tube may be a tracheostomy tube and include a flange towards its rear end adapted to secure the tube with the patient's neck.

According to another aspect of the present invention there is provided a method of forming a tracheostomy comprising the steps of inserting a needle through neck tissue into the trachea, sliding a flexible elongate member through the needle into the trachea, withdrawing the needle, threading the elongate member along a combined dilator and tube, the dilator projecting from the patient end of the tube and providing a tapering leading surface and a smooth continuation with the external surface of the tube, inserting the combined dilator and tube into the trachea along the elongate member, and subsequently withdrawing the dilator rearwardly through the tube such as to leave the tube in position to permit ventilation.

The dilator preferably has a flexible collar extending rearwardly to overlap the forward end of the tube, the collar everting forwardly when the dilator is pulled rearwardly through the tube. The method may include a further step of inflating a sealing cuff on the tube within the trachea.

Tracheostomy apparatus and its method of use, 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 perspective view of the apparatus; Figure 2 is a cross-sectional side elevation view of the patient end of the apparatus before or during insertion into the trachea;

Figure 3 is a cross-sectional side elevation view of the patient end of the apparatus as the dilator starts to be withdrawn from the tube;

Figure 4 is a cross-sectional side elevation view of the patient end of the tube showing the sealing cuff in a deflated condition;

Figure 5 is a cross-sectional side elevation view of the patient end of the tube showing the sealing cuff in an inflated condition; and

Figures 6 to 10 illustrate successive steps in the procedure to insert the tracheostomy tube.

The apparatus comprises an assembly of a tube 1 and a dilator 2, which projects from the forward, patient end 10 of the tube and from its rear, machine end 11.

The tube 1 is similar to conventional tracheostomy tubes in that it has a curved forward portion 12 shaped to extend through a tracheostomy opening in the neck such that its patient end 10 locates within the trachea 3 and is directed generally caudally. The tube 1 is made from a bendable plastics material, such as PVC. The forward portion 12, however, differs from previous tubes in that it is tapered along its length from a relatively small diameter at its patient end 10 to a larger diameter rearwardly. The tube 1 has a neck flange 13 towards its rear end 11, by which the tube is secured with the patient's neck, and a coupling 14 by which connection can be made to the tube. Close to its forward end 10, the tube 1 has an inflatable sealing cuff 15, which communicates with an inflation lumen 16 (Figures 4 and 5) extending through the wall of the tube rearwardly to an inflation line (not shown) in the usual way. The cuff 15 is of an elastic material having a natural shape closely conforming to the external surface of the tube 1 but can be inflated by air supplied through the lumen 16 so that its diameter increases sufficiently for it to seal with the inside of the trachea, as shown in Figures 5 and 10. The cuff 15 is, therefore, of the low- volume/high-pressure kind. The dilator 2 is made of a bendable plasties material, such as PVC, and has an enlarged rear handle portion 20 of cylindrical shape, which abuts the rear end of the coupling 14 on the tube 1 and forms a continuation of the coupling. The dilator 2 continues forwardly from the handle portion 20 as a tubular stem 21 of circular section, the external diameter of the stem being just less than the internal diameter of the tube 1, so that the stem is a close sliding fit within the tube. The stem 21 is hollow, having an axial bore 22 extending along its length. The forward end 23 of the stem 21 projects beyond the patient end 10 of the tube 1 and is formed with a tapered, conical portion 24 projecting forwardly and rearwardly of the forward end of the stem. The patient end 25 of the conical portion 24 has a small diameter and forms a thin lip around the forward entrance to the bore 22. The conical portion 24 tapers rearwardly to an enlarged diameter and, about halfway along its length to the rear it separates from the stem 22 to form a tapering, thin-walled, flexible collar 26 bordering an annular recess 27. The dimensions of the rear end of the conical portion 24 are such that the rear edge 28 of the collar 26 just overlaps the patient end 10 of the tube 1 and the patient end of the tube projects a short distance into the recess 27, as shown in Figure 2. When the dilator 2 is assembled with the tube 1 in the manner shown in Figures 1 and 2, the thickness of the collar 26 at its rear end ensures that there is a very smooth, almost transitionless continuation of the surface between the conical portion 24 of the dilator and the tube. The taper on the conical portion 24 continues along the tube, which further helps provide a smooth transition.

The tube 1 is inserted in the manner illustrated in Figures 6 to 10. With reference first to Figure 6, a hollow needle 60 is pushed through neck tissue 61 until its tip 62 enters the trachea 3. A guidewire 64, or similar flexible elongate member, is then threaded along the needle 60 until its tip emerges into the trachea 3, as shown in Figure 7. The needle 60 is then pulled out, leaving the guidewire 64 in place. The rear end of the guidewire 64 is then threaded into the bore 22 at the forward end of the assembly of the dilator 2 and tube 1 and this assembly is pushed along the guidewire. The thin nature of the leading edge 25 of the dilator 2 and the close match between the diameter of the bore 22 and the external diameter of the guidewire 64 both ensure that there is a smooth continuation from the external surface of the guidewire to the external surface of the dilator. This ensures that trauma caused by entry of the dilator 2 into the neck tissue 61 is minimized and that the force required to insert the assembly is minimized. Further insertion of the assembly causes the passage through the neck tissue 61 to be gradually enlarged. The smooth juncture between the dilator 2 and the tube, where the collar 26 overlaps the patient end 10 of the tube, ensures that this region can be inserted freely into the neck tissue 61 with little trauma. The taper along the tube 1 further enlarges the opening through the neck tissue 61 as the assembly is inserted, until the forward end of the assembly enters the trachea 3, as shown in Figure 9. The sealing cuff 15 is closely contracted about the outside of the tube 1 during insertion so does not present any impediment to insertion, nor is there any substantial risk that the cuff will be damaged during insertion.

The dilator 2 is removed from the assembly at any time after the forward end 10 of the tube 1 has entered the trachea 3. This is done simply by pulling the handle 20 of the dilator 2 rearwardly relative to the tube 1. As this happens, the forward end of the tube 10 moves deeper into the recess 27 and pushes forwardly on the collar 26 until the collar flips forwardly and everts in the manner shown in Figure 3. To ensure that this can be accomplished without damaging the collar, the join between the collar 26 and the forward part of the conical portion 24 has an enlarged flexure recess 29. The flexible nature of the collar 26 allows it to be deformed inwardly as the dilator 2 is pulled rearwardly through the tube l.

Once the dilator 2 has been removed and the tube 1 is correctly positioned, the sealing cuff 15 is inflated to seal the outside of the tube with the inside of the trachea 3, in the usual way.

The arrangement of the present invention enables a tracheostomy tube to be inserted without the need for a separate introducer and dilator. The dilator is preferably ready- assembled in the tube so that the user only needs to insert a single device after removal of the needle. This can speed the procedure appreciably and makes it easier, especially for inexperienced users. It will be appreciated that the invention is not confined to tracheostomy procedures but could be used in other surgical procedures where it is necessary to insert a tube into a body space.

Claims

1. Medico-surgical apparatus comprising a tube (1) and a dilator (2), characterised in that the tube (1) is assembled on the dilator (2) with the dilator extending along the bore of the tube and projecting from its patient end (10) to provide a tapering leading end to the apparatus, that the external surface of the dilator (2) is arranged to provide a smooth continuation with the external surface of the forward end (12) of the tube (1), and that the dilator is arranged such that it can be withdrawn rearwardly through the bore of the tube.

2. Medico-surgical apparatus according to Claim 1, characterised in that the smooth continuation is provided by a flexible portion (26) of the dilator (2) overlapping the forward end (10) of the tube (1).

3. Medico-surgical apparatus according to Claim 2, characterised in that the flexible portion of the dilator (2) is a collar (26) that can be everted when the dilator is pulled rearwardly with respect to the tube (1) to enable the collar to pass through the tube.

4.. Medico-surgical apparatus according to any one of the preceding claims, characterised in that the external surface of the tube (1) is tapered towards its forward end (12).

5. Medico-surgical apparatus according to any one of the preceding claims, characterised in that the tube (1) has an elastic sealing cuff (15) adapted to seal with a body cavity (3) when inflated and to lie close to the tube surface when deflated.

6. Medico-surgical apparatus according to any one of the preceding claims, characterised in that the apparatus includes an elongate flexible member (64) extending along a bore (22) through the dilator (2) and projecting from both ends of the dilator.

7. Medico-surgical apparatus according to any one of the preceding claims, characterised in that the tube is a tracheostomy tube (1) and includes a flange (13) towards its rear end (11) adapted to secure the tube with the patient's neck.

8. A method of forming a tracheostomy comprising the steps of inserting a needle (60) through neck tissue (61) into the trachea (3), sliding a flexible elongate member (64) through the needle into the trachea, withdrawing the needle (60), threading the elongate member (64) along a combined dilator (2) and tube (1), the dilator projecting from the patient end (10) of the tube and providing a tapering leading surface and a smooth continuation with the external surface of the tube, inserting the combined dilator (2) and tube (1) into the trachea (3) along the elongate member (64), and subsequently withdrawing the dilator (2) rearwardly through the tube (10) such as to leave the tube in position to permit ventilation.

9. A method according to Claim 8, characterised in that the dilator (2) has a flexible collar (26) extending rearwardly to overlap the forward end (10) of the tube (1) and that the collar everts forwardly when the dilator is pulled rearwardly through the tube.

10. A method according to Claim 8 or 9, characterised in that the method includes a further step of inflating a sealing cuff (15) on the tube (1) within the trachea (3).