ES2725273B2 - REMOVABLE INTRALUMINAL PROTESIS, SUITABLE FOR THE TREATMENT OF Tracheomalacia - Google Patents

Description

DESCRIPTION

REMOVABLE INTRALUMINAL PROSTHESIS, SUITABLE FOR THE TREATMENT OF TRACHOMOMACY

FIELD OF THE INVENTION

The present invention is framed within the technical field corresponding to that of devices for widening a stricture in a body duct. More specifically, the invention relates, but not limited to, devices for the treatment of an animal tracheal obstruction, especially for canine tracheal collapse. Also, the invention is also applicable in the human field.

BACKGROUND OF THE INVENTION

Among the techniques for the surgical treatment of collapse in a body duct, it is common to use procedures that involve the placement of stents, intraluminal prostheses or stents (both terms will be treated here as synonyms), usually defined as hollow cylindrical prostheses that maintain the luminal permeability and dimensions of a tubular structure by opposing extrinsic compressive forces and providing internal support. Also, within the scope of the invention, the term "intraluminal" will be used, understood as "within the light of any tubular structure or organ".

The placement of stents or intraluminal prostheses is, therefore, a valuable procedure in surgical treatment, since in patients with anatomical limitations, metastatic disease or poor general conditions, the use of minimally invasive techniques, without the need to invade the surrounding tissue It is very helpful.

Specifically, for the treatment of tracheal collapse, there are two different types of prostheses: extraluminal prostheses (rings) that are placed by open surgery, or the mentioned intraluminal prostheses (stents) with a minimally invasive insertion can be used. In turn, in this case, there are essentially two types of intratracheal prostheses or stents, depending on the manufacturing material: plastic prostheses and metal prostheses.

As for stents or plastic intraluminal prostheses, these are made of silicone. These prostheses are especially advantageous because they are economical and easy to remove. Another advantage that they present is the low irritation that occurs in adjacent tissues, as well as the low risk of intraluminal tumor growth that they possess. However, they also have disadvantages: silicone prostheses do not reepithelize and this alters the mucociliary function and increases the accumulation of mucus inside. Another of the disadvantages of these plastic stents is that they are difficult to fix to the wall and therefore can present the problem of migrating more easily. On the other hand, the thickness of its wall is greater, so that the free tracheal light is reduced. Finally, another possible disadvantage to bear in mind is that the mentioned stents require the use of a rigid bronchoscope for placement.

As for metal stents, these can be placed with a flexible endoscope or guided by fluoroscopy, and their implantation requires a short period of anesthesia. As main advantages, the intratracheal diameter of metal stents is greater than that left by plastic prostheses, so it does not interfere with ventilation and, in addition, they allow the formation of new epithelium without altering the generation and accumulation of secretions. On the other hand, at present, the complications derived from these stents are mostly caused by an incorrect estimation of the tracheal diameter and an incorrect estimate of the size of the stent or intraluminal prosthesis. If the chosen stent is too large or has manufacturing defects, it may fracture once placed, or if the size of the stent is smaller than the tracheal diameter, the stent can migrate, causing injury, irritation and a strong cough. The presence of the stent can also cause excessive growth of granulation tissue inside the trachea, reducing the passage of air through it. Another major disadvantage of metal stents is the high risk that exists in their removal, or even the inability to remove them. In the case of childhood tracheomalacia, this is a very important factor since, as the patient grows, the stent should have different dimensions.

As an alternative to these two types of stent, biodegradable stents, whose use is relatively new, have been devised as the last therapeutic option. However, although they seem a promising alternative with lower risks, there are not yet long-term results that are conclusive enough.

Additionally, although known intraluminal stents or prostheses allow certain tracheomalacia treatment needs to be resolved, they are not yet exempt from the technical problem of providing a removable stent that is minimally invasive and that additionally has a radial force exerted on the wall. of the body duct not too high, to prevent further reaction of the tracheal wall and facilitate its subsequent removal.

With the limitations described in the previous paragraphs, it is necessary, in the present technical field, to provide a removable intraluminal prosthesis for the treatment of tracheal collapse or other animal or human body ducts, whose efficiency improves the solutions known in the state of the art. More specifically, an intratracheal prosthesis is necessary that:

- Avoid migration to a greater extent.

- Do not require a large radial force exerted against the tracheal wall.

- Avoid the reaction of the tracheal wall to promote reepithelialization and mucociliary transport; avoiding the accumulation of mucus.

- Avoid fluoroscopy and specific training for implantation.

- Be removable easily and effectively.

- Allow a larger margin for estimating the appropriate size without losing other advantageous technical characteristics.

- Allow to treat the entire tracheal length.

- Require a minimum surgical approach.

- It is manufactured with materials and design that are easy to obtain and have low cost.

For this purpose, the present invention thus proposes a removable intraluminal prosthesis (also referred to as "twine" in the scope of the invention) designed, but not limited to, for the treatment of a tracheal obstruction, whose technical implementation allows to overcome the problems previously detailed.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention relates, but not limited to, the development of a removable intraluminal prosthesis, suitable for use in widening a stricture in a body duct; comprising a main piece of substantially helical geometry formed by a plurality of loops.

Advantageously, said main part is configured so that the adjacent loops have a separation of at least 1 mm from each other; and where said main part also includes at least one fixing point at one of its ends, adapted for coupling or fixing to a suture thread that allows it to be anchored to said body duct.

Using the suture thread of the intraluminal prosthesis, the device can be fixed to the body duct, without this entailing risks that the device migrates once implanted. Additionally, due to the configuration between adjacent loops, which allows the loops to be separated from each other, and due to the fixation point of the intraluminal prosthesis, the total surface area in contact with the body duct and also the radial force exerted on the wall of the latter, since the radial force is no longer the only way of fixing the intraluminal prosthesis, thus improving the state of the art. Additionally, the extraction of the intraluminal prosthesis is viable, firstly, because the location is precise through the suture thread, being always known and it is not necessary to capture it by endoscopy for an extraction. On the other hand, because the pressure against the wall of the body duct is lower (as it is not the only clamping force), and its helical shape, the intraluminal prosthesis can be removed without damaging the tissue and offers low resistance to its extraction.

In a preferred embodiment of the invention, at least one of the ends of the main part is flexible. This allows easy access and prevents injury to the tracheal wall. In addition, the at least one flexible end may be slightly bent in the opposite direction to the direction of the prosthesis loops. So that the end is close to the carina more coupled to the tracheal wall, without exerting excessive force due to its flexible character.

The at least one flexible end may be of the same manufacturing material as the intraluminal prosthesis, or of a different material.

In a preferred embodiment of the invention, the fixing point is coupled to the suture mechanically and / or by means of an adhesive. This achieves a secure coupling between the main piece and the suture thread.

In a preferred embodiment of the invention, the fixing point is shaped like a buttonhole.

In a preferred embodiment of the invention, the cross section of the main part has an expandable diameter. In this way, the main piece can be molded to the desired shape and the appropriate diameter for the body duct.

In a preferred embodiment of the invention, the main part comprises steel and / or nitinol.

In a preferred embodiment of the invention, the main part comprises optical fiber. Manufacturing using this material would have the advantage of greater re-epithelialization of the prosthesis, as well as low tissue reactivity.

In a preferred embodiment of the invention, the suture thread comprises a non-absorbable suture material. More preferably, the suture thread comprises nylon. This ensures the fixation of the intraluminal prosthesis (or twine) to the body duct, eliminating the risk of suture absorption.

In a preferred embodiment of the invention, the main part comprises at one of its ends a widening of between 1 and 10 mm in diametral section, adapted for the location of the intraluminal prosthesis and to facilitate anchoring in an extraction of said intraluminal prosthesis. More preferably, the widening surface area is between 1 and 10 mm2.

This achieves a better location of the intraluminal prosthesis, and provides an anchor point that facilitates the removal of said prosthesis.

In a preferred embodiment of the invention, the loops of the main part have a variable longitudinal separation by the application of a force of contraction or traction. In this way, it is possible to facilitate the proper introduction or removal of the prosthesis by means of an applicator device, by means of the lengthening or contraction of the main piece, bringing the adjacent loops closer or further apart.

Another object of the invention relates to an application kit for an intraluminal prosthesis comprising a removable intraluminal prosthesis according to the above embodiments and a substantially helical geometry applicator, formed by loops of the applicator with a substantially circular crown-shaped cross section, where the main part is configured to be arranged inside said geometry applicator concentric around a longitudinal axis, so that the loops of the main part are housed inside the loops of the applicator.

In a preferred embodiment of the invention, the applicator has a cross section of diameter smaller than the diameter of the cross section of the main part.

This facilitates the implantation of the intraluminal prosthesis into the trachea or body duct, reducing the size or contracting the diametral section of the latter while it is introduced into the trachea with the help of the applicator, which has a slightly smaller diametral section (at minus 2 mm smaller than the diameter of the stent in its expanded position), and then, by removing the applicator (preferably, rotating it around its longitudinal axis so that the stent leaves, loop by loop, the inside of the applicator) to allow the device Acquire the size that has been previously given, for example, with the help of a suitable mold, in its expanded position.

In a preferred embodiment of the invention, the applicator is made of steel or plastic.

In a preferred embodiment of the invention, the length of the main part is between 30 and 130 mm; the separation between adjacent loops is at least 1 mm; the diametral cross section of the main part is between 3 and 30 mm (or, in applications to human patients, up to 50 mm); the diametral cross section of the applicator is at least 2 mm smaller than the diametral cross section of the main part; the cross section of the loops is between 0.2 and 3 mm; and the cross section of the applicator loops is between 0.2 and 3.5 mm for the inner diameter and between 0.3 and 5.5 mm for the outer diameter.

This allows the intraluminal prosthesis to be adapted to the appropriate size and needs of the body duct.

Another object of the invention relates to an intraluminal prosthesis application kit comprising a removable intraluminal prosthesis according to the above embodiments and an extractable device for the removable intraluminal prosthesis. This facilitates the removal of the intraluminal prosthesis. Said device will preferably be configured to apply the traction and / or rotation movements to the prosthesis suitable to its geometry, which allow it to be extracted from the body duct where it is located.

The invention thus allows us to propose a solution for the treatment of animal or human tracheal obstructions. The intraluminal prosthesis of the invention has the ability to be fixed to the surface of the body duct and thus prevent migration, increasing the safety of the device. The invention allows, by having a certain separation between loops, less contact with the wall of the body duct, which reduces the reaction with it, the accumulation of mucus and also reduces the radial force exerted on the tissue, reducing granulation and tissue intrusion

The invention enables the removal of the intraluminal prosthesis, since the permanent location of the prosthesis is ensured by means of the suture, which greatly facilitates its removal through an incision of minimal surgical approach, it being not necessary to extract the prosthesis by forceps and endoscopy. to capture and withdraw it; something that has a failed success rate in typical stent extraction.

Additionally, with the intraluminal prosthesis of the invention, therefore, the need to determine with high precision the diametral size of said prosthesis for the body duct is eliminated, since it is not maintained in its fixed position only by radial force against the wall of the body duct, but is secured by fixing the thread to the body duct. In this way, the need for strong contact with the walls of the body duct is eliminated as the only clamping force of the intraluminal prosthesis to the body duct.

The invention is especially functional for the treatment of canine tracheal collapse, although without limitation to other possible applications, such as its application in human pediatric patients with tracheomalacia.

DESCRIPTION OF THE FIGURES

Figure 1A shows a diagram of the removable intraluminal prosthesis, according to a preferred embodiment of the invention.

Figure 1B shows a detail of the tip of the removable intraluminal prosthesis, according to a preferred embodiment of the invention.

Figure 2 shows a diagram of the longitudinal (bottom) and cross section (top) of the contracted intraluminal prosthesis (Figure 2B) and expanded (Figure 2C) of the invention, and of the applicator (Figure 2A), according to a preferred embodiment of the invention.

Figure 3 shows a diagram of the applicator of the intraluminal prosthesis (Figure 3A) and a detail of the cross section of the loop, and of the contracted intraluminal prosthesis (Figure 3B) and expanded (Figure 3C), according to a preferred embodiment of the invention .

Figure 4 shows some images obtained by Computerized Tomography (CT). It is a cut of the neck of a rabbit with the intraluminal prosthesis implanted in the trachea (4A and 4B), and a 3D reconstruction thereof (4C and 4D), according to a preferred embodiment of the invention.

Figure 5 shows a diagram of the removable intraluminal prosthesis that has a widening at the end of the main piece, according to a preferred embodiment of the invention.

NUMERICAL REFERENCES USED IN THE FIGURES

In order to help a better understanding of the technical characteristics of the invention, the aforementioned Figures 1-5 are accompanied by a series of numerical references where, for illustrative and non-limiting purposes, the following is represented:

DETAILED DESCRIPTION OF THE INVENTION

The following describes a preferred embodiment of the present invention, provided for purposes of illustration but not limitation thereof.

A main object of the invention relates, as described in the preceding sections, and as represented in Figures 1-5 of this document, to a removable twine or intraluminal prosthesis comprising a main part (1) with helical shape formed by a plurality of loops (1 ') and adapted for housing in a body duct (1' ') (preferably the trachea), comprising at least one fixation point (2), adapted for coupling or fixation to said body duct (1 ''), typically by means of a suture thread (3) to the body duct (1 ''). The joint between the fixing point (2) and the suture thread (3) can be mechanical and / or by using an adhesive.

Alternatively, the fixation point (2) may have an eyelet shape to tie the suture thread (3).

In Figure 1A, an image of the stent device of the invention is shown, comprising a helical shaped main part (1) and a fixing point (2) where a suture thread (3) is fixed. The intratracheal prosthesis of the invention further comprises at least one flexible end (2 ’) to prevent injury by inserting the intraluminal prosthesis into the body duct (1’), as shown in Figure 1B. In cases where the material used for the manufacture of the main part (1) is, for example, steel, to obtain the helical main part (1) of the invention in the measure of suitable length and diameter, a cylindrical mold of the desired diameter and a wire that is given the helical shape by winding it around said mold, subsequently removing it and stretching it until obtaining the separation between loops (1 ') of the desired helical. It is then possible to cut the main piece (1) to obtain a certain length, after which the ends (2 ’) are adapted to leave at least one fixing point (2) on one end. Alternatively, more than one fixing point (2) can be adapted. To one of the fixing points (2) the suture thread (3) is then fixed, for example, mechanically, and thus coupled to the main part (1), as shown in Figure 1A.

The material of the wire that will form the main part (1) of the intraluminal prosthesis is preferably a high carbon wire or cable and the material of the wire Suture (3) is preferably nylon or other non-absorbable suture material. Alternatively, the main part (1) may be made of steel, fiber optics and / or nitinol. More preferably, the main part (1) is expandable.

Another object of the invention relates to a kit comprising a stent like the one described and which, furthermore, comprises a hollow helical applicator (4) that houses the main part (1) contracted therein to introduce the stent into a body duct. (1 ''), as seen in Figure 2, which shows a longitudinal section of the applicator (4) (Fig. 2A), of the contracted main part (1) (Fig. 2B) as it would be inside of the applicator (4) and expanded (Fig. 2C), just as it would be once outside the applicator (4). As can be seen in Figures 2 and 3, the stent diameter is smaller in its contracted position (Fig. 2B and 3B) inside the applicator (4) than in its expanded position (Fig. 2C and 3C), outside the applicator ( 4) (Fig. 2A and 3A).

Preferably, the applicator (4) has a diametral section (cross-section of the cylinder that forms the helical envelope) lower both with respect to the diameter of the body duct (1 '') and that of the expanded main part (1) of the stent, to be able to be introduced more easily in the body duct (1``). More preferably the diameter (cross-sectional diametral section) of the applicator (4) is at least 2 mm smaller than the diameter of the main part (1). Once introduced, the applicator (4) is removed thanks to its hollow helical shape, rotating it around its longitudinal axis, and the main helical part (1) of its interior is in the expanded configuration inside the body duct (1 ' ') (Fig. 3).

Figure 3A shows the cross section of a loop (4 ') of the applicator (4) and its hollow shape, where the loops (1') of the helical main part (1) of the stent or intraluminal prosthesis will be housed in its contracted position, as well as the fixation point (2) of the stent, to which the suture thread (3) is fixed or knotted which is flexible.

In another preferred embodiment of the present invention, the main part (1) is made of steel or nitinol.

Figures 4A-4D show images obtained by Computerized Tomography (CT) of a rabbit that has previously been implanted with an intratracheal prosthesis. A 3D reconstruction (4C and 4D) is observed, and two profile views (4A and 4B) of the animal with the intratracheal prosthesis inside. The correct placement of the prosthesis is appreciated, as well as tracheal permeability.

Optionally, the main piece (1) has a widening (5) at one of the ends (2 ’). Said widening (5) may have a diametral section between 1 and 10 mm, and a surface area between 1 and 10 mm2. The widening (5) facilitates the location of the intratracheal prosthesis and also serves as an anchor point in a subsequent stent extraction. Preferably, the widening (5) may be attached to the fixation point (2) of the stent. A widening (5) is shown in Figure 5 at the end (2 ’) of the main part (1), according to a preferred embodiment of the invention.

Another object of the invention relates to a kit comprising, in addition to a stent or a stent and an applicator (4), a stent extractor device, to allow removal of the intratracheal prosthesis.

Therefore, by means of the present invention the technical problem posed is solved, thus improving the state of the art, obtaining the following advantages:

- It is an easily removable intraluminal or twine prosthesis.

- It is not necessary to determine the exact size of the twine (or the size of the trachea or body duct (1``)) with a very high precision, since the twine comprises a suture thread (3) that will be sutured to the body duct (1 ''), thus avoiding migration by these means and not only by radial force.

- It is implanted with minimally invasive surgery, avoiding fluoroscopy and specific training.

- Its design allows a lower radial force, less material in contact with the body duct (1 ’) and, therefore, a lower reaction of the wall of the body duct (1’).

Claims (15)

one.

Removable intraluminal prosthesis, suitable for use in widening a stricture in a body duct (1 ''); comprising a main part (1) of substantially helical geometry formed by a plurality of loops (1 '); characterized in that said main part (1) is configured so that the adjacent loops (1 ') have a separation of at least 1 mm from each other; Y wherein said main part (1) also comprises at least one fixing point (2) at one of its ends (2 '), adapted for coupling or fixing to a suture thread (3) that allows it to be anchored to said conduit body (1``). two.

Removable intraluminal prosthesis according to the preceding claim, wherein at least one of the ends (2 ') of the main piece (1) is flexible. 3.

Removable intraluminal prosthesis according to the preceding claims, wherein the at least one fixation point (2) is coupled to the suture thread (3) mechanically and / or by means of an adhesive. Four.

Removable intraluminal prosthesis according to the preceding claims, wherein the at least one fixation point (2) has an eyelet shape. 5.

Removable intraluminal prosthesis according to the preceding claims, wherein the cross section of the main part (1) has an expandable diameter. 6.

Removable intraluminal prosthesis according to the preceding claims, wherein the main part (1) comprises steel and / or nitinol. 7.

Removable intraluminal prosthesis according to the preceding claims, wherein the main part (1) comprises optical fiber; I where the suture thread (3) comprises a non-absorbable suture material. 8.

Removable intraluminal prosthesis according to the preceding claims, wherein the main part (1) comprises at one of its ends (2 ') a widening (5) of between 1 and 10 mm of diametral section and / or a surface area of between 1 and 10 mm2, adapted for the location of the intraluminal prosthesis and to facilitate anchoring in an extraction of said intraluminal prosthesis. 9. - Removable intraluminal prosthesis according to the preceding claim, wherein the suture thread (3) comprises nylon. 10. - Removable intraluminal prosthesis according to the preceding claims, wherein the loops (1 ’) of the main piece (1) have a variable longitudinal separation by applying a force of contraction or traction. 11. - Application kit of an intraluminal prosthesis, comprising a removable intraluminal prosthesis according to the preceding claims and an applicator (4) of substantially helical geometry, formed by loops (4 ') of the applicator (4) with a shaped cross section of substantially circular crown, where the main part (1) is configured to be arranged inside said applicator (4) in concentric geometry about a longitudinal axis, so that the loops (1 ') of the main part (1) they are housed inside the loops (4 ') of the applicator (4). 12. - Kit according to the preceding claim, wherein the applicator (4) has a cross section of diameter smaller than the diameter of the cross section of the main part (1). 13. - Kit according to any of claims 11-12, wherein the applicator (4) is made of steel or plastic. 14. - Kit according to any of claims 11-13, wherein the length of the main part (1) is between 30 and 130 mm; the separation between adjacent loops (1 ’) is at least 1 mm; the diametral cross section of the main part (1) is between 3 and 50 mm; the diametral cross section of the applicator (4) is at least 2 mm smaller than the diametral cross section of the main part (1); the cross section of the loops (1 ’) is between 0.2 and 3 mm; and the cross section of the loops (4 ’) of the applicator (4) is between 0.2 and 3.5 mm mm for the inner diameter and between 0.3 and 5.5 mm for the outer diameter. 15. - Kit according to any of claims 11-14, further comprising a removable device for the removable intraluminal prosthesis.