EP1796768A2

EP1796768A2 - Tracheostomy apparatus

Info

Publication number: EP1796768A2
Application number: EP05760495A
Authority: EP
Inventors: Emilpaolo Manno
Original assignee: Bioservice SpA
Current assignee: Bioservice SpA
Priority date: 2004-07-12
Filing date: 2005-07-08
Publication date: 2007-06-20
Also published as: AR054297A1; WO2006008602A3; WO2006008602A2

Abstract

The present invention relates to an apparatus for dilation tracheostomy, comprising a dilator element (1), sliding on a guide wire, provided with a dull and tapered distal end portion (2a), suitable to be inserted into a hole made in the tracheal wall (11) of a patient, and provided with an essentially cylindrical handle (3) and a curved portion (2b) that is located between said distal end and said handle, characterized in that it includes at least one expansible element located between said curved portion and said handle.

Description

"TRACHEOSTOMY APPARATUS"

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The present invention relates to a tracheostomy apparatus. Tracheostomy, i.e. the operation wherein a stoma is opened through the tracheal wall, is sometimes required to treat patients suffering both from acute pathologies (traumas, burns, etc.) and from worsening of chronic pathologies (chronic obstructive bronchopathy, neurological syndromes and the like). Tracheostomy is generally concluded by inserting a tracheal tube through the opening created in the tracheal wall. The tracheal tube prevents the opening from closing again, allows direct access to the trachea and permits ventilation.

The tracheal tube has a limited extension, generally a few tens of millimeters, typically extending between a distal end, that will remain inside the tracheal cavity, and an end with a flange, or provided with a connector, that will remain outside the cavity for a possible connection with medical instruments such as ventilation devices, humidifiers (artificial noses), speaking valves, etc..

One of the most widely used materials to produce tubes is polyvinyl chloride (PVC), especially the biocompatible type, that is, which is non-toxic and comfortable for the patient. Normally, tracheal tubes are curved to facilitate insertion into the trachea and to minimize risks of lacerating tissues, both during insertion and during the time the tube remains in the trachea. For this reason they are usually curved. In general the tubes are provided with inflatable elements, for example one or more cuffs, with the function of holding the distal end correctly on the inner tracheal wall once the tube has been inserted, reducing the risk of possible damage to the trachea tissues by contact with said distal end.

The critical insertion step of the tracheal tube is the opening of a sufficiently large stoma in the trachea for the tracheal tube to be housed in. One known method is to surgically create the required opening, i.e. to carry out an incision with scalpels of the tissues which, starting from the skin, cover the trachea progressively, until opening the trachea to form a stoma,. This method is commonly recognized to be invasive and to be avoided in view of the peculiar elasticity of the tracheal tissues, that can be dilated rather than cut and that will close and heal faster if dilated than if surgically opened. To avoid the surgical procedure, various devices and methods have been proposed wherein several consecutive steps are performed with different instruments, in order to gradually, that is elastically dilating the initial incision made on the tracheal wall. A first step is to make the incision in the skin at the site of a space identified between the tracheal rings. A needle is then inserted into this incision to perforate the inner tracheal wall and access the tracheal cavity. A metal guide wire, generally flexible and coated in Teflon, is sliding housed inside the needle, with the function of guiding the insertion of a dilator tube through the small hole made by the needle. The subsequent steps provide the insertion, into said hole, of dilators, i.e. of tapered tubes of increasing diameter, which dilate the needle hole tissues to eventually enlarge it to the required size. Internally, the tubes have a through hole along their entire length (lumen) so that they can slide on the guide wire. The metal wire guides the various dilator tubes that are consecutively inserted into the hole and removed therefrom, ensuring that they do not interfere dangerously with the tissues around the opening that is created. When the opening is sufficiently wide, the tracheal tube is finally housed therein. Use of a guide wire is critical.

This and equivalent methods are particularly invasive. In fact, repeated insertion of various tubes into the trachea causes high risks of damaging the posterior tracheal wall, opposite the opening made, as the distal ends of each tube are generally sufficiently pointed or tapered to cause cuts, lacerations or abrasions of the tissues. Moreover, these types of techniques can easily cause lacerations or traumas which drastically prolong the recovery times of the patient who has had the tracheostomy. These systems are somewhat complicated to handle and personnel require considerable training in their use. In fact, the need to reduce the number and complexity of the steps required in traditional methods has been felt for some time. For this reason, new methods and new instruments have been devised to perform dilation tracheostomy, wherein inflatable elements are used to dilate the hole made with the needle, in lieu of repeatedly inserting tubes with increasing diameters.

A device to perform dilation tracheostomy is for example described in European patent EP 0 784 989. The apparatus comprises a tracheal tube slidingly coupled with a dilator tube, that is coupled to a flexible catheter, provided with a free distal end. The catheter is inserted into the hole made in the trachea and is provided, at its distal end, with an inflatable cuff (or balloon). Once the catheter has been inserted into the aforesaid hole, for example using a metal guide wire, a pressurized fluid is fed to the cuff to expand it. When inflating, the cuff enlarges the hole made in the tracheal wall to define an opening sufficiently large to allow insertion of the tracheal tube. This is obtained by deflating the cuff, pushing the catheter fully into the tracheal cavity and pushing the dilator tube and the tracheal tube into the opening formed by the deflated cuff. Once the tracheal tube is positioned, the catheter is eliminated from the trachea by removing the dilator tube, and with it the catheter, through the tracheal tube. As the catheter is designed to be fully inserted into the cavity of the trachea and to be removed through the tube, which is generally curved, it must be flexible and soft to avoid accidental lacerations or perforations of the posterior tracheal wall. The instruments and methods described in EP 0 784 989, or those equivalent thereto, have a series of drawbacks, too. A first drawback is the fact that it is difficult to position the flexible and soft catheter and to slide it on the guide wire in the insertion step into the needle hole in the tracheal wall. Often the catheter bends to interfere with the walls of the hole. In some cases, for example when the patient is robust in build and the external tracheal wall is covered with a thick layer of tissues, it is necessary to make several attempts before managing to correctly insert the catheter. In other cases it is necessary to resort to the series of tubes with increasing diameters in order to dilate the hole made in the tracheal wall before inserting the catheter.

Moreover, the catheter and dilator tube can easily slide in the tracheal tube only if the curvature of the tube is minimum. This translates into the absolute need for a soft and flexible catheter to avoid the risk of the catheter touching the posterior tracheal wall and perforating it during insertion of the tube. US-A-6, 706,017 (Dulguerov) discloses a tracheostomy device that is said to alleviate the problems of the above discussed patents. To this purpose, the device disclosed by the Dulguerov patent comprises a large diameter needle in which a fiberscope and at least three channels are housed. The needle has a curved distal end portion (ending in a sharpened tip) and a straight handle portion. An inflatable element that extends from the needle end to the straight portion is externally mounted on the needle. No guide wires are provided for and their use is expressly avoided (see e.g. col. 4, lines 30-31). The device results in a method wherein the tracheal wall is perforated by the large-diameter needle and the lumen thus obtained is enlarged by radially expanding the inflatable element.

This device and the relevant method have several drawbacks; the main one is that the needle is quite large: because it has to house one fiberscope and several ducts, its diameter is relatively large, i.e. a diameter similar to that of a pencil. This means that when the needle is inserted into the tracheal wall, and the tissues are cut by the needle, a corresponding circular portion of tissues could be cut and removed from the trachea by the large needle. This is obviously detrimental to a quick and good healing of the incision once the tracheal tube has been removed; in other words, such a large incision would jeopardize the advantages above mentioned with regard to the elasticity of the tracheal tissues.

Other drawbacks of the Dulguerov device, and also of the previously mentioned traditional instruments provided with inflatable elements is that these elements do not guarantee uniform dilation of the tissues with which they come into contact and that they will at least partially obstruct the trachea.

Often, the inflatable elements yield at some parts and are rigid at others, for example due to unwanted variations in the thickness of the materials composing them. For this reason it may be difficult to make openings with an essentially constant diameter in the tissues, without any narrowing. Moreover, the inflatable cuffs of the known devices are almost always partially positioned within the tracheal duct; this means that the cuff portion that is not in contact with the tracheal wall but that is within the tracheal duct will expand more than the cuff portion that is contacting the tracheal wall. The result of this differential expansion is an insufficient dilatation of the lumen in the tracheal wall and a partial obstruction of the tracheal duct. Because the average diameter of the tracheal duct is about 3 cm, it is clear that an even partial obstruction could be very detrimental. It is an object of the present invention to provide a tracheostomy apparatus and a method which solve, simply and inexpensively, the prior art drawbacks, allowing patients to be treated quickly, with minimum risks of accidental damage to the tissues involved.

A further object of the present invention is to provide an inflatable cuff, associable with surgical instruments, which allows to uniformly dilate the surrounding tissues.

These and other objects are obtained by the present invention which relates to an apparatus for dilation tracheostomy, comprising a rigid and hollow dilator element, that can be guided by an external guide wire, provided with a free distal end, tapered and dull, suitable to be inserted into a hole previously made in the tracheal wall of a patient, said guiding wire being positioned in said hole, said apparatus having a straight portion including a handle portion and a curved portion located between said tapered distal end and said straight portion, and at least one inflatable element externally located between said curved portion and said handle portion. The apparatus according to the invention provides many advantages over the prior art: it allows the tracheostomy to be performed on a patient rapidly, without requiring the use of a series of tubes or of a catheter. Dilation of the tissues at a hole made in the tracheal wall may in fact be obtained by means of the inflatable element provided directly before the curved portion with respect to its direction of insertion, i.e. on the first part of the straight portion of the apparatus.

Preferably, the inflatable element is a cuff, essentially cylindrical in its inflated configuration, positioned immediately upstream the curved portion of the dilator element, for example at a cross-sectional narrowing thereof. As the device does not include a catheter, or an equivalent instrument, which after use must be removed from the trachea through the distal end, it is possible to use substantial angles between the distal end of the device according to the invention and the straight portion, with evident advantages with regard to easy of use. Preferably, the angle formed by the distal end with the handle of the apparatus, i.e. angle a between axis A-A of the device straight portion 2c and axis B-B of (straight) distal end 2a (see fig. 5) is approximately within the range of 90 degrees to 150 degrees. The possibility of using an angle within this range results in a marked reduction of the risk of perforations, lacerations, and damages in general to the inner tracheal wall, i.e. the wall that is opposite to the wall through which the distal end is inserted.

In fact, once correctly inserted in the trachea, the distal end of the apparatus of the invention is close to coaxial or slightly inclined with respect to the axis of the tracheal cavity. This considerably reduces risks of contact with the posterior tracheal wall. At the same time, because the cuff is located on the first part of the straight portion, close or adjacent to the curved portion, the correct positioning of the dilator is readily recognized by a condition of the apparatus axis A-A substantially perpendicular with respect to the trachea. According to an aspect of the invention, the dilator element is provided with one or more stop elements to limit insertion of said distal end in the trachea to one or more predefined positions. It is thus easier for the user of the ό apparatus to insert the first cuff in the correct position, into the opening obtained by inserting the distal end through the tracheal wall. According to a further aspect of the invention, the dilator element and the first cuff may be provided with a lubricating and, if necessary, antibacterial hydrophilic coating.

The device of the invention is extremely simple to operate. The distal end is inserted through the tracheal wall for example into a hole previously made using a syringe needle, i.e. a traditional needle having reduced diameter. The apparatus is associated with a guide wire of known type. In this case the apparatus is hollow, that is, it has a longitudinal through hole, or lumen, in which the guide wire slides.

The tapered distal end, pushed through the tracheal wall, produces a first dilation of the surrounding tissues. The device is then pushed further through the tracheal wall and positioned so that the first cuff is inserted into the thus made opening. Once the cuff has been inserted into the opening, a pressurized fluid is supplied through to inflate the cuff and therefore dilate the tissues adjacent thereto. Once the opening has been sufficiently dilated, the first cuff is deflated to allow insertion of a tracheal tube into the opening made in the tracheal wall. The degree and speed of inflation of the first cuff may be adjusted by acting on the inflation pressure.

The present invention also relates to an inflatable element associable with surgical instruments of the type utilized to dilate tissues, characterized in that it is produced through injection molding of thermoplastic materials and has a portion with a first opening, a truncated-cone shaped portion with a second opening having a smaller diameter to the one of the first opening. Advantageously, an inflatable element thus produced has walls with uniform and/or constant thickness between its different parts and, consequently, it also has essentially the same mechanical properties at all of its points. For example, the first cuff of the apparatus of the invention may be produced by injection molding of thermoplastic materials such as PVC. The first cuff produced in this way has high mechanical properties which allow uniform dilation of the tissues on which the cuff acts, with minimum, or even negligible, yield at the intermediate sections of the cuff. Consequently, the risks of cross-sectional narrowing in the opening obtained with the apparatus of the invention are also decreased.

Further aspects and advantages of the present invention shall be more apparent from the following description, that is given purely as a non-limiting example with reference to the accompanying schematic drawings, wherein: Figure 1 is a side view of a device according to the invention inserted through the tracheal wall of a patient;

Figure 2 is a side view of the device in Figure 1 during inflation of the inflatable element;

Figure 3 is a side view of an auxiliary dilator element without cuffs; Figure 4 is a perspective view of an inflatable element according to the invention; and

Figure 5 is a sectional view of a preferred device according to the invention.

Figure 1 shows an apparatus according to the present invention partially inserted through the tracheal wall 11 of a patient undergoing tracheostomy. The device 1 according to the invention is substantially rigid or semi-rigid and is provided with a dilating part 2 and a straight portion S including a handle 3, essentially cylindrical.

With substantially rigid it is here meant a rigidity sufficient to allow the tapered end to dilate the small hole punctured into the trachea by the needle. Suitable rigidity values are 70 shore A to 90 Shore D, preferably 80-90 Shore D.

The dilating part 2 comprises a distal end portion 2a that is tapered and dull, i.e. it does not comprise a sharpen point that could make an incision in the trachea tissues. The dilating part 2a is tapered so as to have a smaller end to allow its insertion into a hole made by a needle in wall 11 of the trachea and a larger opposite portion to dilate the tissues around the hole. Distal end portion 2a is preferably straight or essentially rectilinear and is connected to a curved part 2b. Part 2b is connected to the straight portion S of the invention device, that is including a first straight, i.e. rectilinear, part 2c, and a second straight portion consisting in a handle 3. The invention apparatus 1 is hollow, i.e. it has a through hole 4, the function of which is to allow a wire, of the type utilized to guide the tubes traditionally used for tracheostomy, to slide inside the apparatus body. The apparatus body can be made of plastic or metallic materials, but is preferably produced in PVC or polyurethane (PU) or other resin materials having the above specified Shore values. In one embodiment of the invention the distal end is provided with a hydrophilic coating of a known type and, if necessary, provided with antibacterial properties obtained by incorporating methyl blue or metallic silver (from AgNO₃ solution) in the material (PVC or PU) with which the element is produced. The apparatus of the invention is provided with an expandable, that is, radially inflatable element, located between the curved portion 2b of dilating part 2 and handle 3, i.e. it is positioned on the straight portion 2c, which extends as a connection element between the curved portion 2b and the handle 3. In figures 1 and 5 the inflatable element is fixed to portion 2c in correspondence with a throat or cross-sectional narrowing 6. In the shown embodiments, the inflatable element is located between the portion 2b of the distal end and the handle 3 and is a cuff 5, externally positioned around portion 2c which connects the dilating part 2 to handle 3. More specifically, the diameter of portion 6 is smaller than the diameter of the rest of portion 2c, to obtain an essentially uniform diameter of the dilator at the dilating end 2 and at the portion covered by the inflatable element 5. The cuff or inflatable element 5 is coaxial to portion 2c and extends therearound through 360 degrees forming a sleeve inside which portion 2c is housed. The ends of cuff 5 are held sealed on the apparatus 1 to allow the cuff to be pressurized and inflated to the dimensions of required dilation of the stoma in the trachea; in this condition, the diameter of the cuff 5 is greater than the diameter of the dilating part 2 8fig. 2 and 5.

The cuff is in fluid communication with external means to supply a pressurized fluid. In one embodiment, cuff 5 communicates, for example through a flexible duct 8, with a second cuff 7, which in turn can be supplied with a pressurized fluid, for example saline solution, or air. For this reason the second cuff 7 is provided with a valve 9 that allows coupling with a syringe or with an external line.

In the preferred embodiment of fig. 5, the cuff 5 is directly connected through duct 19 to a luer valve 9a and to a source of pressurized fluid (not shown), i.e. no second cuff or plenum is provided.

The cuff 5 has an essentially cylindrical extension. This form allows it to be positioned simply in the opening A produced in the tracheal wall 11 and also allows to engage opening A for its entire width. The cuff 5 is of the type known in the art for use as a dilator, such as described in the cited European patent no. 0 784 989, and is obtained by injection molding or extrusion of thermoplastic materials, for example PVC, in tubular form and subsequently shaped by pressurization to obtain the desired conformation, that is, tapered at the ends, for fixing on the straight portion 2c of the dilator apparatus 1. Figure 4 shows an alternative embodiment wherein the cuff 13 has a first cylindrical portion 14, a second truncated-cone shaped portion 15 having an essentially cylindrical end 16 with a second opening 18. The diameter of the opening 18 is smaller than the diameter of the aperture 17 of the cylindrical portion, to allow this cuff to be injection molded and avoid subsequent deformation by pressurization. The two ends 17 and 18 can be sealed to portions of the dilator with corresponding diameters. Alternatively, two cuffs are positioned symmetrically against each other and overlapped and fixed to each other in correspondence of the openings 17 to obtain a final product with the same shape as the one in Figure 2. The preferred material has a rigidity within the range of 50 to 65 Shore A, preferably of 60 Shore A.

The cuffs produced with this technique have a uniform thickness, that is, practically constant at all their points. Consequently, the mechanical properties of the various portions of a cuff are also essentially constant. For this reason, in the case in which it is produced with the aforesaid technique, the cuff 5, expanding under the action of the pressurized fluid, dilates the tissues around the opening A uniformly, as it is not subject to localized yield. Figure 3 shows a dilator element 1A without any expansible element or cuff. Element 1A has smaller dimensions, i.e. a smaller diameter than the apparatus 1 of Figures 1 , 2 and 5, and is intended for the purpose of performing, when necessary, a first gradual dilation of the ostomy obtained with the needle, before inserting dilator apparatus 1.

Figure 2 shows the apparatus during the dilation step through cuff 5. Once the dilator element 1 has been positioned as shown in Figure 1 , that is, with the first cuff 5 inserted in the opening A, a pressurized fluid is supplied to the cuff 5. In the case shown the fluid is injected for example with a syringe into the second cuff 7, through the valve 9, and from here passes into the first cuff 5 which inflates in the opening A, dilating it. The pressure of the first cuff 5, which may not be completely visible when inserted into the wall 11 , can be controlled through the second cuff 7, which acts as a control element. In particular, acting manually on the second cuff 7 it is possible to increase or decrease the pressure inside the first cuff 5 and also adjust the speed with which said cuff 5 is inflated or deflated.

Once the cuff has been fully inflated and the opening A has reached the required dimensions, cuff 5 is deflated to allow insertion of a traditional tracheal tube (not shown) through the wall 11. Operation of apparatus 1 of the invention is extremely simple. The dilating part 2 is inserted through the tracheal wall 11 , in a hole previously made by means of a syringe and, if necessary, enlarged with first dilator 1A having a decreased diameter (Figure 3). The apparatus 1 may be associated with a guide wire of known type. In this case, the apparatus 1 may be hollow, that is, it may be provided with a longitudinal through hole, or lumen, in which the guide wire can slide. The dilating part 2, inserted through the tracheal wall 11 , produces a first dilation of the surrounding tissues. The apparatus 1 must be pushed further through the tracheal wall 11 and positioned so that cuff 5 is inserted into the opening A thereby produced. Once the cuff 5 has been inserted into the opening A, a pressurized fluid (gas or liquid) is supplied through duct 19 or through the second cuff 7, to inflate the first cuff 5 and therefore dilate the tissues adjacent thereto. Once opening A has been sufficiently dilated, cuff 5 is deflated to allow insertion of a tracheal tube into the opening A produced in the tracheal wall. The degree and speed of inflation of the first cuff 5 may be adjusted by acting on the inflation pressure of the fluid fed to cuff 5.

Operation of the apparatus 1 of the invention is therefore extremely simple, as it does not require the use of a catheter or of a series of tubes. Also, the time required to perform the tracheostomy is much shorter with respect to the typical time of traditional instruments.

Moreover, the device 1 allows the tracheostomy to be performed with a high degree of safety, with minimum risks with regard to accidental lesions to the tracheal wall 10. In fact, the dilating part 2 forms with the handle 3 a substantial angle, as no catheter is required to slide inside it. Preferably, the dilating part 2 forms with the straight portion 2c an angle within a range from approximately 90 degrees to 150 degrees. As shown in Figures 1 and 2, the dilating part 2, once inserted into the trachea, is inclined or close to parallel with the tracheal cavityaxis. In this way, the risks of the dilating part 2 coming into contact with the wall 10 are minimized, together with the risks of lesions to said wall 10. Moreover, also in the case of contact with the wall 10, the dilating part 2 would not touch the wall 10 with the tip, but with a rounded portion, i.e. with the curved portion 2b.

By using a dull point of end portion 2a and an inflatable cuff 5 only a small hole is required, that is successively enlarged without further incisions or cuts.

The apparatus may be provided with one or more stop elements (not shown) the function of which is to prevent insertion of the dilating part 2 into the trachea beyond one or more predefined positions. For example, one or more flanges or stop surfaces may be provided on the handle 3, with an adjustable position on said handle 3, suitable to insist on the external tracheal wall 11. The stop means simplify insertion of the dilating part 2 into the trachea, preventing it from erroneously being inserted beyond the useful length for the cuff 5 to dilate the opening A. These means (not shown) may for example be moved along the handle 3 according to predefined positions that take into account the expected thickness of the wall 11.

Claims

1. An apparatus for dilation tracheostomy, comprising a dilator element (1 ), that is guided by an external guide wire, provided with a free distal end (2a), tapered and dull, to be inserted into a hole previously made in the tracheal wall (11) of a patient, said guiding wire being positioned in said hole, said apparatus having a straight portion (2c, S) including a handle (3) and a curved portion (2b) located between said tapered distal end (2a) and said straight portion (2c), characterized in that it comprises at least one expandable element (5) externally located on said straight portion (2c), between said curved portion (2b) and said handle portion 83).

2. An apparatus as claimed in claim 1 , wherein said expandable element comprises an inflatable cuff (5), essentially cylindrical when inflated, positioned on said rectilinear portion (2c) of said dilator, at a cross-sectional narrowing (6).

3. An apparatus as claimed in claim 2, wherein said cuff (5) is in fluid communication with a second cuff (7) to which a pressurized fluid can be supplied, said second cuff (7) acting as a plenum for control of the pressure of cuff (5).

4. An apparatus as claimed in any previous claim, wherein the axis (B-B) of said distal end (2a) forms, with said axis of said portion (2c), an angle a within the range of 90 degrees to 150 degrees.

5. An apparatus as claimed in any previous claim, further comprising a stop element to limit insertion of said distal end into the trachea to a predefined position.

6. An apparatus as claimed in any previous claim, wherein said distal end portion (2a), said curved portion (2b) and said cuff (5) are provided with a hydrophilic coating.

7. An apparatus as claimed in any previous claim, further comprising as a kit a further and separate dilator element (1A), having a smaller diameter than the diameter of said dilator element provided with a cuff.

8. An inflatable element (5) associable with surgical instruments of the type utilized for the dilation of tissues, characterized in that it is produced through injection molding of thermoplastic materials and comprises a cylindrical portion (14) with a first end opening (17) and an essentially truncated-cone shaped portion (15) with a second end opening (16).

9. An inflatable element as claimed in claim 8, characterized in that the walls of said inflatable element have an essentially constant thickness throughout their area.