EP2173395A2

EP2173395A2 - Implantable device with a metal and/or ceramic coating and corresponding production method

Info

Publication number: EP2173395A2
Application number: EP08775584A
Authority: EP
Inventors: Pascal Paganon; Christian Mai; Jean-Paul Gilbert Ricol
Original assignee: Compagnie Europeenne dEtude et de Recherche de Dispositifs pour lImplantation par Laparoscopie SA
Current assignee: Compagnie Europeenne dEtude et de Recherche de Dispositifs pour lImplantation par Laparoscopie SA
Priority date: 2007-02-21
Filing date: 2008-02-21
Publication date: 2010-04-14
Also published as: FR2912659A1; FR2912659B1; WO2008122713A3; WO2008122713A2

Abstract

The invention relates to an intra-gastric balloon (1) for treating obesity, wherein said balloon (1) is to be implanted in the stomach of a patient for reducing the internal volume of the stomach, said balloon (1) including at least one first flexible pocket (2) to be filled with an inflating fluid, said flexible pocket (2) having an inner face (2A) and an outer face (2B) opposite each other, characterised in that a metal and/or ceramic coating (5) covers the inner (2A) and/or outer (2B) face in order to increase the tightness of the pocket (2) to the inflating fluid.

Description

IMPLANTABLE DEVICE AND METHOD OF MANUFACTURE

CORRESPONDING

TECHNICAL AREA

The present invention relates to the technical field of implantable medical or surgical devices for containing a fluid.

The invention particularly relates to devices intended to be implanted in or around biological organs constituting a pocket or a duct for reducing the internal volume of the organ concerned, for example the volume of the stomach in the context of a treatment against obesity. But if the invention preferably falls within the field of medical or surgical treatment of obesity, it also relates to other medical or surgical applications, such as the treatment of urinary or faecal incontinence (artificial sphincter), flow control in blood vessels, plastic surgery or the injection of drugs into the human body (implantable site).

The invention more specifically relates to an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient to reduce the internal volume of the stomach, said balloon comprising at least one first flexible pouch intended to be filled with an inflation fluid, said flexible pouch having an opposite inner face and an opposite outer face.

The invention also relates to an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient to reduce the internal volume of the stomach, said method comprising a manufacturing step at least a first flexible pouch intended to be filled with an inflation fluid, said flexible bag having an opposite inner face and an opposite outer face.

PRIOR ART

To treat patients with obesity, it is known to implant directly into the patient's stomach, by medical means (ie by natural means: mouth and esophagus) a volume intragastric balloon enough to reduce the space available for food, while reducing their speed of passage. Such an intragastric balloon generally comprises a flexible bag made of a biocompatible elastomer material, said flexible bag being intended to be inflated by a fluid

(liquid or gas) once installed in the stomach, to reduce the internal volume of the latter.

These intragastric balloons known, if they generally give satisfaction, nonetheless exhibit certain disadvantages.

Thus, the bag of these known intragastric balloons intended to contain the inflation fluid generally has a certain porosity, which will allow the gradual leakage of the fluid contained therein and thereby gradually decrease the volume of the balloon, and therefore the therapeutic efficacy of the latter. This problem is accentuated when the intragastric balloon is only filled with a gas, such as air, while a filling with a gas is precisely extremely desirable, in order to minimize the weight of the balloon and thus improve the comfort of use for the patient.

Improving the tightness of the flexible bag of the balloon for containing the inflation fluid is in practice particularly delicate because it is subject to many technical constraints. Indeed, this flexible pouch is subjected to deformations (folding of the very tight pocket prior to implantation to allow passage through the natural channels, deformation of the pocket under the effect of the inflation pressure within the stomach) may deteriorate any sealing coating deposited on its surface.

It is further necessary that the pouch retain a thin, flexible wall so that it can be folded sufficiently tightly so that, once folded, the pouch can pass through the mouth and esophagus.

In addition, in order to allow the balloon to be properly deployed in the stomach, it is necessary for the bag, which is initially folded tightly on itself, to have a non-sticky and preferably relatively slippery contact to facilitate its operation. inflation and prevent it remains stuck on itself in its initial configuration folded.

This pocket is also manufactured in a clean room and its tightness can not be obtained by processes likely to pollute the atmosphere of the clean room.

This bag is also likely to be subjected to sterilization operations, for example by gamma radiation, which means that the tightness of the bag must not be damaged by the sterilization of the latter.

Last but not least, the treatment against obesity can be relatively long (at least several months), it is necessary that the pocket maintains its durability permanently.

These sealing problems also arise for devices other than intragastric balloons, and for example for inflatable gastric rings intended to grip the stomach, for cosmetic surgery implants (breast implants in particular) filled with a fluid such as a silicone gel, for example, or for injection and / or fluid sampling devices within the patient's body (implantable site, for example). example in the context of chemotherapeutic treatments).

SUMMARY OF THE INVENTION

The objects assigned to the invention therefore aim to remedy the problem set out in the foregoing and to propose a novel implantable intragastric balloon comprising at least a first pouch which, while having a high and durable seal, retains a flexible character.

Another object of the invention is to propose a novel implantable intragastric balloon comprising at least a first flexible pouch of particularly simple and economical construction.

Another object of the invention is to propose a novel implantable intragastric balloon comprising at least a first flexible bag made of a material having good biocompatibility and mechanical strength properties.

Another object of the invention is to provide a new implantable intragastric balloon comprising at least a first flexible bag having excellent airtightness.

Another object of the invention is to provide a novel implantable intragastric balloon comprising at least a first flexible pouch that can be folded very tight to allow its introduction endoscopically. Another object of the invention is to propose a new method for manufacturing an intragastric balloon impiantable comprising at least a first flexible pouch which is particularly simple and economical.

Another object of the invention is to provide a novel method of manufacturing an implantable intragastric balloon comprising at least a first flexible bag which allows the bag to maintain excellent sealing even after swelling of said bag.

Another object of the invention is to provide a new method for manufacturing an intragastric balloon impiantable comprising at least a first flexible pouch, which allows to confer on said flexible pouch a tight character in a particularly reliable and uniform manner.

The objects assigned to the invention are achieved with the aid of an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient to reduce the internal volume of the patient. stomach, said balloon comprising at least a first flexible bag to be filled with an inflation fluid, said flexible bag having an opposite inner face and an opposite outer face, characterized in that a metal and / or ceramic coating covers the inner face and / or the outer face to increase the seal of the bag to the inflation fluid.

The objects assigned to the invention are also achieved by the method of producing an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient to reduce the risk of obesity. internal volume of the stomach, said method comprising a step of manufacturing at least a first flexible pouch intended to be filled with an inflation fluid, said flexible pouch having an opposite inner face and an opposite outer face, said method being characterized in that it comprises a sealing step during which the internal face and / or the outer face by a metal coating and / or ceramic to increase the seal of the bag to the inflation fluid.

DESCRIPITF SUMMARY OF DRAWINGS

Other objects and advantages of the invention will appear better on reading the following description, as well as with the aid of the accompanying drawings, given for purely illustrative and non-limiting purposes, in which:

- Figure 1 illustrates, in a schematic cross-sectional view, an intragastric balloon according to a first embodiment of the invention.

- Figure 2 illustrates, in a schematic cross-sectional view, an intragastric balloon according to a second embodiment of the invention.

BEST MODE OF REALIZING THE INVENTION

The invention relates to an implantable device 1 in a human or animal body. The device 1 according to the invention may be a medical device (that is to say that can be implanted without surgery, by natural means) or a surgical device (that is to say, requiring the implementation surgical procedures for implantation within the patient's body).

In what follows, reference will be made to the description of a preferred embodiment of the invention according to which the device 1 constitutes an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient, preferably by natural means (oral: mouth then esophagus) to reduce the internal volume of the stomach, since the balloon occupies a large part of the space available for food.

The invention is however not limited to an intragastric balloon and the device 1 according to the invention may for example constitute, in another embodiment not claimed, a gastric ring for the treatment of obesity, intended gripping the stomach of a patient to reduce the diameter of passage of the stomach, and more specifically an inflatable gastric ring so that the diameter of the ring is adjustable by injection or withdrawal of fluid.

The device 1 may also constitute, according to other embodiments of the invention not claimed, a plastic surgery implant (preferably a breast implant) or a device for injecting and / or sampling fluid within the body of the patient, such a device is generally referred to as the "implantable site" or "injection port". Such an implantable site is intended to be introduced by a skin incision under the skin of the patient, and then to serve as a stitching zone for injecting therapeutic products (of the chemotherapy type, for example), or even to take a fluid within the patient's body. (such as blood for example).

The intragastric balloon 1 illustrated in the figures, which constitutes, as indicated previously, an example of a medical or surgical device according to the invention and in particular an intragastric balloon, is expandable, that is to say that it is designed to occupy on the one hand a loose configuration, in which it is likely to occupy a restricted volume favoring its implantation, and on the other hand an expanded or inflated configuration in which it occupies a substantially predetermined volume, for example of the order 600 milliliters, corresponding to its functional volume of use. For this purpose, the balloon 1 comprises at least a first flexible bag 2 intended to be filled with an inflation fluid, so that the filling of your first flexible bag 2 by the inflation fluid allows the balloon 1 to pass from its loose configuration (allowing it to occupy a restricted volume) to its expanded configuration (shown in the figures). The filling of the balloon 1 is preferably carried out once the balloon is positioned within the stomach. To this end, the balloon 1 is equipped with a valve (not shown and known per se) which allows the communication of the interior of the first flexible bag 2 with a source of fluid located outside the body of the patient, the balloon being connected to said source by a filling catheter passing through the patient's mouth and esophagus and connected to the balloon valve.

Of course, it is possible to use different types of inflation fluid, including liquid, semi-liquid or gaseous fluids. In order to minimize the weight of the balloon, and thus make the latter more bearable for the patient, it is preferable that the first flexible bag 2 be filled with a gas, for example air. In this case, the first flexible pouch 2 is therefore advantageously designed to be filled with air as an inflation fluid.

As illustrated in the figures, the balloon 1 may comprise a single flexible bag 2 (as in the variant of FIG. 1) or two flexible bags 2, 3 (as in the variant of FIG. 2). In the variant of Figure 2, only your first flexible pouch 2, which is disposed within the second pocket 3, is intended to be filled with an inflation fluid. In this case, the first flexible pouch 2 actually acts as inflation means ("air chamber") for the second flexible pouch 3. In other words, in the embodiment of FIG. the swelling of the first flexible bag 2 by the inflation fluid causes the radial expansion of the first flexible close 2 which will come to press against the second flexible bag 3, in the same way that an air chamber presses against a tire, to give the second flexible pouch 3 its functional volume. Of course, a greater number of pockets (for example three, four or more) may be provided, each pocket may even possibly be inflated with a different fluid. Preferably, the first pocket 2 has, when inflated, a substantially spherical shape.

According to the invention, the first flexible pouch 2 has an inner face 2A (located opposite the internal volume 4 for accommodating the inflation fluid) and an opposite outer face 2B. The first flexible pouch 2 can be made of any material known to those skilled in the art and compatible with the medical-surgical environment of the invention.

Preferably, the first flexible pouch 2 is made of a polymeric material, and preferably of an elastomeric material, and even more preferably of a biocompatible elastomeric material.

Advantageously, the first flexible pouch 2 consists of a single-layer polymeric or elastomeric envelope, that is to say that it consists of a single unitary film, one-piece, of this polymeric or elastomeric material. In other words, the flexible bag 2 is formed of a single layer of said material. In order to facilitate the operations of extraction of the flask by natural means, the first flexible pouch 2 preferably has a thickness substantially less than 600 microns, and even more preferably substantially less than 500 microns.

Advantageously, said flexible pouch 2 has a thickness less than

300 microns, and more precisely between 10 and 200 microns, preferably substantially equal to 150 microns, allowing an excellent compromise between sealing (especially gas) and bulk.

Advantageously, the bag 2 is made by a polyurethane membrane whose thickness is substantially less than 600 μm, and preferably substantially equal to 150 microns. The combination of such a first pocket 2 with a second pocket 3 (including the first pocket 2), for example made of silicone, which has a thickness advantageously substantially equal to 500 microns makes it possible to obtain a tight and easy to extract balloon by the natural ways. For example, the first flexible pouch 2 is made of silicone, which gives it good mechanical strength and a biocompatible nature.

Preferably, particularly in the case where the soup bag 2 is intended to be filled with air, said first flexible pouch 2 is made of polyurethane which allows it to confer good sealing properties. For example, in the embodiment of Figure 1, the first pocket 2 which in itself constitutes the balloon 1, is made of silicone. In the example of FIG. 2, the first pocket 2 is made of polyurethane while the second pocket 3 is made of silicone.

Even if the polyurethane (for example) itself has a relatively low porosity, and therefore a relatively tight seal, its qualities are insufficient to maintain a high level of tightness over the entire duration of the treatment (which is several months, for example six months).

This is why, in accordance with the invention, a metal and / or ceramic coating 5 covers the inner face 2A and / or the outer face 2B of the first flexible pouch 2 to increase the sealing of said pouch 2 with the fluid particularly when the latter is a gas. Thanks to the microscopic structure ordered (for a metal) or pseudo-ordinate (for a ceramic) of the coating 5, it is possible to compensate for the porous nature of the material constituting the flexible pouch, a porous character which is particularly accentuated when the flexible pouch 2 is made of a polymer material of the polyurethane or silicone type. The implementation of a metallic and / or ceramic coating thus makes it possible to considerably increase the level of tightness of the flexible bag 2, in particular when the latter is made of an elastomer. This metallization or ceramization of the flexible bag 2 further allows the bag 2 to retain its flexibility properties. In other words, the combination of a metal and / or ceramic coating and a flexible material (such as an elastomer) makes it possible to obtain a wall having an excellent gas barrier effect, even when the coating 5 is thin compared to the thickness of the pocket 2 itself.

Preferably, the metallic and / or ceramic coating 5 of the first flexible pouch 2 is designed to protect said pouch 2 from the aggressive action of the gastric juices, which are in particular of particularly acidic nature. In this case, the coating 5 is designed to participate significantly in aging resistance in situ (that is to say in the stomach) of the material constituting the pocket 2, especially when the latter consists of a polymeric membrane or fine elastomeric (for example a polyurethane membrane whose thickness is of the order of 150 microns).

In addition, such a metal and / or ceramic coating makes it possible to avoid the need for a stack of several layers of film of polymer material to obtain a flexible bag 2 that is sufficiently gas-tight.

The invention thus makes it possible to reduce the thickness of the bag 2 (since the use of a stack of polymeric layers is no longer necessary for the seal, thanks to the coating 5) and therefore to reduce very significantly the effort required to the extraction of the balloon 1 from the patient's stomach at the end of treatment. In short, the invention thus makes it possible to obtain an intragastric balloon whose introduction and extraction by natural means is facilitated. The invention covers the following configurations:

the coating 5 covers only the internal face 2A,

the coating 5 covers only the outer face 2B,

the coating 5 covers both the inner face 2A and the outer face 2B (in the case of the variants illustrated in FIGS. 1 and 2),

the coating 5 is a coating made entirely of metal,

the coating 5 is a completely ceramic coating,

the coating 5 is mixed and comprises metal portions and ceramic portions; for example, the coating 5 is ceramic on the inner face 2A and metal on the inner face 2B (or vice versa).

In the case where, as illustrated in FIG. 1, the balloon 1 comprises a single flexible bag 2, it may be preferable, unlike the variant illustrated in FIG. 1, for the coating 5 to cover only the inner face 2A of the first flexible pouch 2. In this way, the coating 5 is preserved from any direct aggression from the external environment that constitutes the interior of the stomach, which is particularly binding from the physico-chemical point of view.

This technical arrangement (coating 5 only on the inner face 2A) makes it possible to better preserve the integrity of the coating 5 while minimizing the risk of particles belonging to the coating 5 being detached from the outer face 2B in order to disperse in the patient's organism.

On the other hand, in the embodiment illustrated in FIG. 2, it is conceivable, as illustrated in FIG. 2, for the coating 5 to cover both the internal face 2A and the external face 2B of the first flexible pouch 2. (which is preferably polyurethane), as far as where this first flexible pouch 2 is disposed inside the second flexible pouch 3 (preferably made of silicone), the latter thereby constituting a protective barrier for the coating 5 disposed on the outer face 2B.

Preferably, the coating 5 consists essentially of a biocompatible material, in particular when the coating 5 is intended, as in the variant of Figure 1, to be in direct contact with the body of the patient. It is of course conceivable, particularly in the embodiment corresponding to FIG. 2, that the material constituting the coating is not necessarily biocompatible. Indeed, in the embodiment of Figure 2, the coating 5 is isolated from the outside by the second pocket 3.

Preferably, the coating 5 consists essentially of a material having a polycrystalline structure, such a structure promoting the sealing of the coating 5 due to the multiplicity of distinct crystalline grains present within it and oriented differently relative to each other . Preferably, the coating 5 consists essentially of a material having a compact stack crystallographic structure, which contributes to minimizing the porosity of the coating 5, so as to give the latter a high level of sealing.

For example, the material constituting the coating 5 preferably has a cubic crystallographic structure with all faces centered, cubic centered or hexagonal compact. However, it is conceivable, without departing from the scope of the invention, that the material constituting the coating 5 does not have a compact stack crystallographic structure but for example a semi-compact crystallographic structure. Preferably, the material constituting the coating 5 is chosen from the materials having not only a polycrystalline structure but also a crystallographic structure compact stack, and preferably cubic centered or cubic all centered faces.

Advantageously, the coating consists essentially of a material chosen from the following group:

- metals: gold, silver, platinum, titanium, aluminum,

- ceramics: alumina, zyrcone, titanium oxide.

The implementation of a coating 5 essentially made of gold is particularly advantageous because the gold has, in addition to a pofycristalline compact stack structure, a relatively soft and malleable character, which allows to maintain an excellent seal despite the different deformation operations to which the bag 2 (folding, unfolding, inflation) is subjected, as well as a perfectly biocompatible and stainless character (which is important insofar as the device 1 is intended to be introduced into the humid environment and acid of the stomach).

Thus, the metallization of the flexible bag 2, in particular with gold, makes it possible to give the latter durably sealed character without affecting its other properties, including flexibility and strength.

It is possible to obtain such properties even when the thickness of the coating 5 is relatively small, and for example between 0.05 μm and 150 μm. Excellent results are obtained with a metal coating whose thickness on the face 2A, 2B it covers is between 50 and 100 microns. Preferably, in the case where the flexible bag 2 is made of silicone, it is possible to deposit, prior to the deposition of a metal coating, an underlayer on said flexible bag 2 to promote the adhesion of the metal on said pocket flexible 2.

Such a metal coating of the flexible bag 2 of the balloon 1 is also particularly advantageous, especially when it is a gold coating, to improve the aging resistance of the balloon 1, aging bonded in particular to the aggression of the stomach environment. Such a gold coating also makes it possible to reduce the number of layers of polymer material constituting the flexible pouch 2 and thus to promote very clearly the extraction of the balloon 1 at the end of treatment. This advantage is illustrated in the following example

Example:

An effort test is made to extract an intragastric balloon from the pig. The intragastric balloon used is in accordance with the balloon described above. The balloon is placed in the stomach of the pig and inflated in its functional form. He is then deflated for his withdrawal. The test consists of measuring the extraction effort provided by a surgeon to remove the intragastric balloon, previously deflated, from the pig's stomach by natural routes (esophagus and mouth). The measurement of the extraction force, expressed in Newtons, is carried out using a dynamometer connected at one end to the intragastric balloon and at the other end to the surgeon's hand.

The objective of the test is to measure the incidence of metallization, with gold, of one of the faces of the internal pocket of a balloon on the extraction force of said balloon. Three different intragastric balloons are compared using the above-mentioned test:

Balloon 1: it is an intragastric balloon composed of a single silicone bag intended to be filled with a liquid, said bag having a thickness of 500 μrn and being produced using a single layer of silicone (referred to as "S" in the summary table below),

- Balloon 2: this is an intragastric balloon composed of an external silicone pouch (S) and an internal polyurethane bag (designated by the acronym "PU" in the summary table below) ) disposed inside the outer pocket and intended to be inflated by a gas. The outer pocket has a thickness of 500 microns while the inner pocket has a thickness of 200 microns. The outer pocket is formed of a single layer of silicone (S) while the inner pocket is formed of two layers of polyurethane (PU) superimposed. One of the faces of the inner pocket is metallized with gold, ie it is covered with a gold coating whose thickness is in this case of the order of 130 nm,

- Balloon 3: it is an intragastric balloon identical to the balloon 2, except for its inner bag which is composed of a single layer of polyurethane (PU) whose thickness is 150 microns. As is apparent from the table above, the metallization (in this case gold) of the inner flexible pouch improves the sealing of the latter, so that a single layer of film of polymer material is sufficient for producing said internal flexible pouch. This leads to a reduction in the thickness of the inner bag (Example 3), which considerably reduces the extraction force of the balloon with respect to the same balloon comprising no metallization on its inner bag (Example 2). Thus, the extraction force is, for example, reduced to almost 30% when the internal pocket is metallized with gold relative to the extraction force when the internal pocket is not metallized. and therefore thicker.

The metallization of the internal pocket thus makes it possible, for a balloon comprising several pockets, to obtain results in terms of extraction force that are substantially identical to those obtained with an intragastric balloon comprising a single non-metallized silicone pocket (example 1).

Therefore, the effort made by the surgeon to extract the intragastric bailon by natural routes at the end of treatment is considerably

reduced compared to a similar balloon filled with air (Example 2), without the seal being adversely affected, quite the contrary.

Thus, the coating 5 of the flexible bag 2 thus allows both a better sealing of the inflation fluid and better extraction of the intra-gastric balloon 1 at the end of the therapy.

Preferably, the first flexible pouch 2 is formed by the meeting of superimposed flexible sheets and attached together along a junction line. For example, two flat sheets of polyurethane are superimposed one against the other and attached together, at their interface, along a junction line having a substantially loosened shape, and preferably a substantially circular shape. Preferably, the junction line is a high frequency welding line. In this case, it is preferable to first make the bag 2 by high frequency welding, then to metallize (or ceramic coating) the bag 2 thus obtained. Indeed, the presence of a coating on the bag 2, and in particular a metal coating, is likely to hinder or prevent the implementation of a high frequency welding, while such a welding mode is particularly interesting from the point of view of its efficiency as well as its ease and its cheapness.

The invention also relates to a method of manufacturing an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient to reduce the internal volume of the stomach, and in particular a balloon 1 according to the subject of the foregoing description. In what follows, the method according to the invention will also be described in connection with the manufacture of an intragastric balloon. The manufacturing method according to the invention is thus preferably a method of manufacturing an intragastric balloon for the treatment of obesity, said balloon being intended to be implanted in the stomach of a patient to reduce the internal volume of the stomach.

Of course, the method according to the invention can be adapted to the manufacture of other types of implants and can thus constitute, in a non-limiting manner, a method of manufacturing a gastric band for the treatment of obesity, a method of manufacturing a plastic surgery implant (preferably a breast implant), or a method of manufacturing a device for injecting and / or sampling fluid within the patient's body (implantable site) .

The manufacturing method according to the invention comprises a step of manufacturing at least a first flexible pouch 2 intended to be filled with an inflation fluid, said flexible pouch 2 having an inner face 2A and an opposite outer face 2B. According to the invention and as explained above, the method comprises a sealing step during which the inner face 2A and / or the outer face 2B is covered by a metal and / or ceramic coating to increase the watertightness of the the bag 2 to the inflation fluid, which is preferably constituted by air.

According to a preferred embodiment, the step of manufacturing the first flexible bag 2 comprises the meeting of superimposed flexible sheets and attached together along a junction line, the latter being preferably made by high frequency welding of said sheets. Of course, other welding techniques such as heat sealing or laser welding can also be implemented without departing from the scope of the invention.

Preferably, once the sheets joined along the junction line, the walls of the assembly thus obtained are subjected to a subsequent deformation operation, carried out for example by inflation of said assembly to a sufficient pressure to cause the plastic deformation of the wall and thus lead to the flexible bag 2.

The sealing step may be carried out before the manufacturing step of the first bag 2, or intervene during the step of manufacturing the first bag 2, for example after assembly of the sheets constituting the bag 2 but before the deformation plastic of said sheets described above In the latter case, during the plastic deformation of the wall constituting the pocket, the inner surface of said wall will be biased in compression while the outer surface will be stressed in traction, which means that the coating If present on said inner surface will undergo a deformation different from that of the coating 5 possibly present on said outer surface. These different deformation stresses make it possible to shift the pores of each of the materials involved (that is to say the material forming the inner lining, the material forming the outer coating and the material constituting the wall of the pocket), pore shifting which of course complicates the exit path of the inflation fluid and thus increases the level of tightness of the bag 2.

In general, it is also particularly advantageous, whatever the method of production chosen, to coat both the inner face 2A and the outer face 2B of a metallic and / or ceramic coating, in the to the extent that under the effect of the swelling of the first pocket 2, the inner face 2A will be subjected to a compression stress, while the inner face 2B will be subjected to a tensile stress resulting from the curve of the pocket 2, this differential deformation of the three layers involved making it possible, as already explained, to shift on a microscopic scale the pores contained in the thickness of the coating layers 5 with respect to the pores contained in the thickness of the wall of the pocket 2 interposed between the coating layers 5. In this way, the gas barrier properties of the bag 2 are particularly optimized.

It may also be advantageous to implement the sealing step subsequent to the manufacturing step of the first bag 2, in particular when this manufacturing step involves a high frequency welding. Indeed, some coatings 5, in particular when they are of a metallic nature, can considerably hinder the high frequency welding so that it is preferable to deposit the coating 5 after the high frequency welding operation has been performed.

Advantageously, the method according to the invention comprises, prior to the sealing step, a step of swelling of the first bag 2, so as to perform the sealing step on the first inflated bag 2, it is that is, the latter is in its final functional configuration (expanded configuration). This procedure avoids the coating 5 is altered under the effect of mechanical stresses resulting from swelling of the bag 2 in the stomach. Thus, by depositing the coating on the bag 2 while the latter is in a configuration similar to that of its end-use configuration, it is possible to give said bag optimized and durable sealing properties.

Preferably, the swelling step of the first bag 2 is performed by hermetically closing said first bag 2 while the latter is at atmospheric pressure, then placing the first bag 2 thus closed in a vacuum chamber. Thus, under the effect of the vacuum that surrounds it, the first pocket 2 whose interior 4 is at atmospheric pressure will naturally swell. The first pocket 2 being thus swollen under vacuum, the coating 5 is deposited during the sealing step, by vapor deposition (CVD).

The vapor phase deposition technique is well known as such and consists in vacuum evaporating a material, preferably a metallic material, said material then redeposing by condensation on the surface to be coated.

Preferably, it is also conceivable that the coating 5 is deposited on the flexible bag 2, during the sealing step, by physical vapor deposition (PVD). Indeed, by this technique, it is conceivable to produce for example a cold plasma deposition which avoids possible damage to the material constituting the flexible bag 2, by too high a temperature.

In this way, it is possible to coat the outer face 2B of the pocket 2 exposed to the condensation of the coating material. Advantageously, the sealing step comprises, when the coating is deposited by vapor deposition, an operation of simultaneous rotation of the first pocket 2, preferably along two orthogonal axes of rotation, to promote uniform coverage of said first pocket 2 by the coating 5.

If it is desired to coat the inner face 2A according to this vapor deposition technique, it is then necessary to implement a step of turning the first pocket 2 on itself, to reverse the positioning of the inner faces 2A and external 2B and thus be able to subject the uncoated side to the condensation of the coating material.

This reversal step can also be performed only to place the coated face inside the pocket 2, and thus avoid that said face coated is not in direct contact with the external environment, for the reasons already mentioned in the foregoing.

Of course, the invention is absolutely not limited to the implementation of a coating by vapor deposition of the coating 5. It is for example quite possible to deposit the coating 5 by coating.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the design and manufacture of implantable medical devices, in particular for the treatment of obesity.

Claims

1 - Intragastric balloon (1) for the treatment of obesity, said balloon (1) being intended to be implanted in the stomach of a patient to reduce the internal volume of the stomach, said balloon (1) comprising at least a first flexible bag (2) intended to be filled with an inflation fluid, said flexible bag (2) having an opposite inner face (2A) and an opposite outer face (2B), characterized in that a coating (5) metal and / or ceramic covers the inner face (2A) and / or the outer face (2B) to increase the seal of the bag (2) to the inflation fluid.

2 - Balloon (1) according to claim 1 characterized in that the first flexible bag (2) is formed by the meeting of superimposed flexible sheets and attached together along a junction line.

3 - Balloon (1) according to claim 2 characterized in that said connecting line is a high frequency welding line.

4 - Ball (1) according to one of claims 1 to 3 characterized in that the first flexible bag (2) is made of a polymeric material, and preferably an elastomeric material.

5 - Balloon (1) according to claim 4 characterized in that the first flexible pouch (2) is formed of a single layer of said polymeric material.

6 - Balloon (1) according to one of the preceding claims characterized in that Ia first flexible pouch (2) has a thickness substantially less than 600 microns. 7 - Ball (1) according to one of the preceding claims characterized in that Ia first flexible pouch (2) has a thickness substantially equal to 150 microns.

8 - Ball (1) according to one of the preceding claims characterized in that the first flexible bag (2) is made of polyurethane or silicone.

9 - Ball (1) according to one of claims 1 to 8 characterized in that said coating (5) covers only the inner face (2A) of the first flexible bag (2).

10 - Ball (1) according to one of claims 1 to 8 characterized in that said coating (5) covers both the inner face (2A) and (a external face (2B) of the first flexible bag (2) .

11 - Ball (1) according to one of the preceding claims characterized in that said coating (5) consists essentially of a biocompatible material.

12 - Ball (1) according to one of the preceding claims characterized in that said coating (5) consists essentially of a material having a polycrystalline structure.

13 - Balloon (1) according to one of claims 1 to 12 characterized in that said coating (5) consists essentially of a material having a compact stack crystallographic structure or a semi-compact crystallographic structure.

14 - Ball (1) according to one of claims 1 to 11 characterized in that said coating (5) consists essentially of a selected material in the following group: gold, silver, platinum, titanium, aluminum, alumina, zyrcone, titanium oxide.

15 - Ball (1) according to one of the preceding claims characterized in that the thickness of said coating (5) is between 0.05 microns and 150 microns, and preferably is between 50 microns and 100 microns.

16 - Ball (1) according to one of the preceding claims characterized in that it comprises a second flexible pouch (3) of silicone within which is disposed the first flexible pouch (2), which is polyurethane.

17 - Ball (1) according to claim 16 characterized in that the second flexible pouch (3) has a thickness substantially equal to 500 microns.

18 - A method of manufacturing an intragastric balloon (1) for the treatment of obesity, said balloon (1) being intended to be implanted in the stomach of a patient to reduce the internal volume of the stomach , said method comprising a step of manufacturing at least a first flexible pouch (2) intended to be filled with an inflation fluid, said flexible pouch (2) having an inner face (2A) and an outer face (2B) opposed, said method being characterized in that it comprises a sealing step during which the inner face (2A) and / or the outer face (2B) is covered by a coating (5) made of metal and / or ceramic to increase the tightness of the pocket (2) to the inflation fluid.

19 - Process according to claim 18 characterized in that the step of manufacturing the first flexible pouch (2) comprises the meeting of superimposed flexible sheets and attached together along a junction line. 20 - Process according to claim 19 characterized in that the junction line is made by high frequency welding of said sheets.

21 - Method according to one of claims 18 to 20 characterized in that the sealing step is performed prior to the manufacturing step of the first pocket (2),

22 - Method according to one of claims 18 to 20 characterized in that the sealing step is performed after the manufacturing step of the first pocket (2).

23 - Method according to one of claims 18 to 22 characterized in that it comprises, prior to the sealing step, a step of swelling of the first pocket (2), so as to perform the step of sealing on the first bag (2) inflated.

24 - Process according to claim 20 characterized in that the swelling step of the first pocket (2) is performed by hermetically sealing said first pocket (2) while the latter is at atmospheric pressure, then placing the first pocket (2) thus closed in a vacuum chamber.

25 - Method according to one of claims 18 to 24 characterized in that during the sealing step, the coating (5) is deposited by vapor deposition.

26 - The method of claim 25 characterized in that the sealing step comprises an operation of rotating the first pocket (2) to promote uniform coverage of said pocket (2).