WO2008059137A2

WO2008059137A2 - Implantable medical device with pressure limiter

Info

Publication number: WO2008059137A2
Application number: PCT/FR2007/001806
Authority: WO
Inventors: Gilbert Ricol Jean-Paul
Original assignee: Compagnie Européenne D'etude Et De Recherche De Dispositifs Pour L'implantation Par Laparoscopie
Priority date: 2006-10-31
Filing date: 2007-10-31
Publication date: 2008-05-22
Also published as: WO2008059137A3; EP2086476A2; FR2907665B1; FR2907665A1

Abstract

The invention relates to an implantable medical device (1) including at least one inflatable chamber (2), the volume of which can be modified with the injection or removal of an inflation fluid, characterised in that the device includes a pressure limiting means (4) intended to be implanted inside the patient and provided with a reversible relief member (11) designed to enable excess inflation fluid to flow from the inflatable chamber (2) and arranged to adopt alternatively a closed configuration when the fill pressure is less than or equal to a critical pressure value and an open configuration when the fill pressure exceeds the critical pressure, such as to maintain the fill pressure substantially below the critical pressure.

Description

IMPLANTABLE MEDICAL DEVICE WITH PRESSURE LIMITER

TECHNICAL AREA

The present invention relates to the field of implantable medical devices comprising a pneumatic or hydraulic element of variable volume, including implantable medical devices for the treatment of obesity such as gastric rings or intragastric balloons.

The present invention more particularly relates to an implantable medical device comprising at least one inflation chamber whose volume is modifiable by injection or withdrawal of an inflation fluid.

PRIOR ART

There are numerous medical devices which comprise a pneumatic or hydraulic effector in the form of an inflation chamber constituted by a flexible bag whose volume is likely to be modified by introduction under pressure or, contraήo, by purging, a gas inflating fluid (air) or liquid (physiological saline).

By way of examples, mention may in particular be made of balloon-type devices used for the occlusion of blood vessels or the deployment of stents, or else inflatable constriction rings intended to reduce the section of a natural duct such as the sphincters. artificial or gastric rings, or finally the balloon devices and more particularly intragastric balloons to be introduced into the stomach to reduce the volume to treat obesity. In the various examples of use mentioned above, the functional adjustment of the implantable medical device essentially depends on the level of inflation of the latter, that is to say the amount of inflation fluid that contains the inflation chamber for this purpose and the pressure exerted by said chamber on the tissues.

For example, it is easily understood that a gastric ring must be able to strangle the stomach sufficiently to limit its volume without creating a complete occlusion nor a lesion of the stomach wall.

In addition, it is generally necessary to avoid over inflation of the inflation chamber to prevent any degradation thereof which would be detrimental to the longevity and / or normal operation of the implantable device.

For example, in the case of a gastric band whose inflation chamber is delimited by an elastic membrane capable of deforming in a centripetal radial direction so as to grip the stomach, it should avoid any excessive deformation likely to cause irreversible plastic distension of said membrane. Indeed, such distension could in particular cause the appearance of a kind of hernia, resulting in poor placement of the ring relative to the stomach and some loss of efficiency of the clamping exerted by said ring.

Moreover, when the inflation fluid exerts too much pressure within the inflation chamber, it can cause the latter to burst, with harmful consequences both for the medical device, which must then be replaced, and for the tissues in which said device is implanted. In order to control the inflation of the medical devices of the prior art when they are implanted in the patient, it is known to monitor the behavior of said device in vivo using an endoscopic instrument which allows the practitioner to appreciate judging the functional volume of the device relative to its environment.

Although they generally provide satisfaction, such methods of controlling inflation have, however, significant disadvantages.

Firstly, the use of invasive endoscopic equipment, whether introduced by natural means or through an incision, multiplies the instruments necessary for the intervention, and therefore increases the complexity and cost of the latter.

In addition, the purely visual nature of the surveillance and the smallness of the visual field offered by the endoscope do not systematically make it possible to constantly carry out an exhaustive control of the entire implantable device, so that overpressures resulting in a bad operation of the device, local distensions of the inflation chamber, hernias, or even leaks, may occur without being detected.

SUMMARY OF THE INVENTION

The objects assigned to the present invention therefore aim to remedy the disadvantages mentioned above and to propose a new implantable medical device comprising at least one inflation chamber whose volume is modifiable by injection or withdrawal of an inflation fluid, which has improved reliability and operational safety. Another object of the present invention is to provide a new implantable medical device whose design is particularly simple and cheap.

Another object of the invention is to propose a new implantable medical device which has a particularly atraumatic character for the patient in which it is implanted.

Another object of the present invention is to provide a new implantable medical device for the treatment of obesity.

Another object of the present invention is to provide a new implantable medical device which has good compactness.

The objects assigned to the invention are achieved by means of an implantable medical device comprising at least one inflation chamber whose volume is modifiable by injection or withdrawal of an inflation fluid characterized in that it comprises a means pressure limiter for implantation within the patient and provided with a reversible exhaust member adapted to allow excess fluid to flow out of the inflation chamber, said exhaust member being arranged to alternatively adopt a closure configuration in which it prevents the passage of the inflation fluid when the pressure in said inflation chamber, called "filling pressure", is less than or equal to a predetermined value, called "critical pressure", and a opening configuration in which it allows the passage of the inflation fluid when the filling pressure exceeds said critical pressure, maintaining the filling pressure substantially below the critical pressure at least when injecting the inflation fluid into said inflation chamber. SUMMARY DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will appear better on reading the description which follows, as well as with the aid of the attached drawings, given purely by way of non-limiting illustration, among which:

- Figure 1 illustrates, in a view from above, a first embodiment of an implantable medical device according to the invention.

FIG. 2 illustrates, in an enlarged partial sectional view, a part of the medical device of FIG.

- Figure 3 illustrates, in a view from above, a second embodiment of an implantable medical device according to the invention.

- Figure 4 illustrates, in a cross-sectional view A-A, a portion of the device of Figure 3 in a first configuration.

- Figure 5 illustrates, in a cross-sectional view A-A, the device of Figure 3 in a second configuration.

BEST MODE OF REALIZING THE INVENTION

The medical device 1 according to the invention is intended to be introduced into a patient, either by natural means or by a surgical incision.

Preferably, said device 1 constitutes a medical device which is fully implantable, that is to say which penetrates entirely inside the patient, through the surface of the body of the latter. However, within the meaning of the invention, the medical implantable device may also constitute the invasive portion of a device intended to partially penetrate the body of the patient in the more or less long term.

Preferably, the device 1 according to the invention is an implantable device for the treatment of obesity, and more particularly a gastric ring for the treatment of obesity.

According to another alternative embodiment, the device 1 according to the invention may constitute an intragastric balloon for the treatment of obesity.

According to yet another variant embodiment, the device 1 according to the invention may constitute a balloon intended to be introduced into a vessel or a natural cavity of the body, for example to seal said vessel, eliminate a thrombosis or even deploy a reinforcement. stent type.

The device 1 according to the invention comprises at least one inflation chamber 2 whose volume is modifiable by injection or withdrawal of an inflation fluid. In other words, the inflation chamber 2 constitutes a sealed deformable pocket adapted to receive and contain a variable amount of inflation fluid, the adjustment of the volume occupied by said inflation chamber 2 depending on the amount of inflation fluid which is introduced into said pocket.

Within the meaning of the invention, the existence, the range and the effectiveness of the therapeutic action of the device 1 are determined and actively controlled by the volume occupied by the inflation chamber 2 and / or by the pressure prevailing in the latter, said chamber therefore constituting an actuator (or effector) pneumatic or hydraulic. More particularly, the inflation chamber 2 according to the invention is preferably adapted to adopt alternately a contracted configuration, in which it occupies a restricted volume which facilitates the introduction of the device 1 into the patient, and an expanded configuration in which it occupies a larger functional volume than contracted configuration.

Preferably, the inflation chamber 2 is delimited, at least in part, by an expandable wall 3 whose extension makes it possible to increase the volume of said inflation chamber 2. By way of example, such an expandable wall 3 may be formed by a flexible membrane intended to be deformed elastically and / or plastically, or by a bellows whose vesicles are substantially folded on themselves at rest and able to be deployed under the effect of the internal pressure prevailing in the chamber inflation 2.

When it is desired to inflate the device 1 according to the invention to give it a particular functional form in which it exerts the desired therapeutic effect, it is necessary to increase the volume of the inflation chamber 2 by adding fluid thereto. inflation.

However, resistant forces tend to oppose mechanically the increase in volume of the inflation chamber 2. It may be an intrinsic structural resistance related to the deformation energy, elastic or plastic, necessary for deployment of the extensible wall 3. It may also be an external resistance exerted by the environment of the device 1, for example by the stomach in the case of a gastric ring or by the stent to be deployed in the case of an expansion balloon.

In order to overcome the resistant forces, it is therefore necessary to exercise sufficient driving pressure within the chamber of inflating 2, that is to say to introduce under pressure the inflation fluid in the latter.

According to an important characteristic of the invention, the device 1 comprises a pressure limiting means 4 arranged to maintain the pressure of the inflation fluid in the inflation chamber 2, called the "filling pressure", substantially below a value predetermined, called "critical pressure" P _c at least when the inflation fluid is injected into said inflation chamber 2.

In other words, the pressure limiting means 4 according to the invention is able to regulate, especially when introducing or seeking to introduce under pressure additional inflation fluid in the inflation chamber 2, the filling pressure so as to avoid any over-inflation likely to injure the patient, to cause a malfunction or a loss of efficiency of the device 1, or even to irreversibly degrade said device 1, in particular by excessive plastic deformation, or even bursting, of the extensible wall 3.

In particular, the pressure limiting means 4 according to the invention advantageously makes it possible to absorb, in real time, any overpressure beyond the critical pressure P ₀ , and in particular any peak of temporary overpressure occurring during the phases of injection of the fluid. inflation.

Of course, the pressure limiting means 4 according to the invention may also be arranged to automatically regulate the pressure in the inflation chamber 2 during treatment, for example in the event of overpressure occurring during an accidental crushing of said chamber 2.

Within the meaning of the invention, the pressure-limiting means 4 is implanted within the patient with the device 1. The critical pressure P _c constitutes a tolerance threshold preferably defined on the basis of two criteria:

- A material criterion, the critical pressure must not exceed a fraction of the burst pressure, that is to say the filling pressure in which the chamber 2 irreversibly degrades or even bursts. Said fraction can be set according to an arbitrary or regulatory security factor.

A medical criterion, the compression force exerted by the device 1, and more particularly by the chamber 2, on the patient's tissues must not lead to lesion of said tissues.

Depending on the structure, dimensions and purpose of the device 1, tests may enable the manufacturer to empirically determine a maximum allowable filling pressure and to adapt the pressure relief means 4 accordingly.

In what follows, it will be considered for convenience of description that the device 1 constitutes a gastric ring for the treatment of obesity, without this constituting a limitation of the invention.

In a well-known manner, as shown in FIGS. 1 and 3, such a gastric band is formed by a flexible band 5 intended to be closed towards its two ends 5A ₁ 5B by a closure system 6 around the stomach to reduce the diameter of the stomach cavity. The inflation chamber 2 then extends substantially along the entire length of the flexible band 5 so that the extensible wall 3 can exert a centripetal radial constriction within the loop formed by said band.

Preferably, as shown in FIGS. 1 and 3, the implantable device 1 also comprises an implantable site 7 forming a point access port for injection or puncture of inflation fluid. Said implantable site 7 usually comprises for this purpose a cavity extending between a puncture zone 8 capable of being pierced by a needle, preferably formed by a self-sealing elastomeric membrane or "septum", and an outlet orifice intended to be connected to a catheter 10.

In a manner well known to those skilled in the art, the implantable site 7 is connected to the gastric band, and more specifically to the inflation chamber 2, by means of a catheter 10 preferably formed by a tubular of elastomeric material, such as silicone.

According to a preferred embodiment, the pressure limiting means 4 is provided with an exhaust member 11 designed to be able to put the inflation chamber 2 in communication with the outside of the device 1 in order to evacuate at least part of the inflation fluid to the outside of said device 1, and more precisely within the body of the patient.

In other words, the exhaust member 11 constitutes an overflow which allows the excess fluid to be emptied out of the chamber 2, preferably into the tissues surrounding said exhaust member 11.

Preferably, the escapement member 11 is reversible and arranged to alternatively adopt a closure configuration (see FIGS. 2 and 4) in which it prevents the passage of the inflation fluid, when the filling pressure is less than or equal to the critical pressure P _c , and an opening configuration (see Figure 5) in which it allows the passage of the inflation fluid to the outside, when the filling pressure exceeds the critical pressure P _c . Conversely, the reversible escapement member 11 naturally returns to its configuration of closing when the filling pressure has fallen back to an acceptable level, below the critical pressure.

In other words, the escapement member 11 according to the invention ensures the maintenance of the tightness of the inflation circuit, normally closed, constituted by the inflation chamber 2, the catheter 10 and the cavity of the implantable site. 7 when the pressure in the inflation chamber 2 is less than or equal to the critical pressure P ₀ , and creates a controlled leak on the inflation circuit 2, 7, 10, whenever said pressure exceeds the critical pressure P _c , so as to allow the flow out of said inflation circuit of the excess inflation fluid causing the overpressure, as shown by the arrow Fi. As such, it will be noted that, although the escapement member 11 is in the closed position in FIG. 2, the arrow Fi has been shown in said figure to indicate the leakage path that can be taken by the fluid of FIG. inflation when the exhaust member adopts its opening configuration.

According to an alternative embodiment illustrated in FIGS. 3, 4 and 5, the exhaust member 11 is associated with a retention pocket 12.

According to the invention, said retention pocket 12 is intended to form a buffer zone between the inflation chamber 2 (and more generally the inflation circuit 2, 7, 10) and the outside of the device 1, so as to limit the mechanical impact of the flow of the inflation fluid on the tissues surrounding the exhaust member 11.

In particular, the retention pocket 12 may advantageously be designed to widen the dispersion zone of the inflation fluid, in order to reduce the pressure stress that said inflation fluid exerts locally on the surrounding tissues when it escapes from the inflation circuit. inflation 2, 7, 10, or to moderate the instantaneous leakage rate of the inflation fluid. Although the retention pocket 12 can be sealed and intended to contain the inflation fluid discharged from the chamber 2, it is particularly preferably bounded by a porous membrane which allows slow diffusion of the inflation fluid from the inside. from the retention pocket 12 to the tissues surrounding the exhaust member 11, as represented by the arrows F ₂ , F ₃ , F ₄ .

The retention pocket 12 according to the invention can therefore advantageously fulfill the role of a "expansion vessel" or "expansion vessel" which limits the instantaneous power of the discharges of inflation fluid into the environment of the implantable device 1 , and more specifically, which time-scales the exhaust pressure and the leakage rate of the inflation fluid, temporarily storing said inflation fluid when it is discharged from the inflation chamber 2, and then gradually releasing it neighborhood of the device 1.

Advantageously, the evacuation of the fluid out of the retention pocket, and more particularly the dispersion of the surplus fluid of inflation in the tissues, avoids unnecessarily and durably ballasting, or even unbalancing, the device 1.

According to a preferred embodiment, the device 1 comprises an operating indicator designed to indicate to the practitioner that the pressure limiting means 4 has tripped, that is to say that inflation fluid has escaped from the circuit inflating 2, 7, 10 by the exhaust member 11.

For this purpose, it will be possible to design the retention pocket 12 so that it is deformable under the constraint of the inflation fluid discharged by the exhaust member 11, and use an operating indicator which comprises a radiopaque load integrated in the structure of said retention pocket 12, said radio-opaque charge allowing the practitioner to visualize the deformation of said retention pocket 12, for example by radioscopy.

Thus, said retention pocket 12 may advantageously serve, especially during the injection of the inflation fluid, means for controlling the occurrence of an overpressure indicating to the practitioner that the maximum capacity of inflation of the device has been reached.

According to another variant of embodiment, it is possible to envisage including directly in the inflation fluid a radiopaque contrasting element which enables the practitioner to visualize a possible filling of the retention pocket 12 or a dispersion of said fluid in the tissues. , this event signaling that the critical pressure has been reached and that the pressure limiting means 4 has been requested.

According to an alternative embodiment illustrated in FIGS. 1 and 2, the pressure limiting means 4 comprises a calibrated valve 14.

As is well known to those skilled in the art, said calibrated valve 14 can be provided with a movable closure element 15, such as a ball, which tends to be held in a sealed manner against a seat 16 by means of resilient return 17, spring type, so as to close an orifice communicating with the inflation chamber 2, as shown in Figure 2.

Of course, it is conceivable to use adjustment elements, such as prestressing wedges, in order to determine or adjust the critical pressure P _c necessary for the displacement of the movable closure member 15 against the means of elastic return 17, that is to say, more generally, to provide the device 1 with means for adjusting the sensitivity of the pressure-limiting means 4. According to another variant embodiment illustrated in FIGS. 3, 4 and 5, the pressure limiting means 4 comprises a lip valve 20.

Said lip valve 20 is preferably formed of an elastic wall 21 which separates the inflation chamber 2, or an element of the inflation circuit 2, 7, 10, from the outside of the device 1, said wall 21 being elastic and slit by a through cutout line 22 so that it defines a pair of lips 23A, 23B. Said lips are arranged to open when a filling pressure is exerted on them exceeding the critical pressure _Pc , so as to allow the escape of the inflation fluid, then to join spontaneously by springback, so as to reconstitute a sealed barrier as soon as the filling pressure has fallen below the critical pressure value P _c .

According to a preferred embodiment illustrated in FIGS. 1 and 2, the gastric band, and more particularly the flexible band 5, is provided with one or more gripping tongues 24 intended to facilitate its manipulation by the practitioner responsible for its implantation. , and the pressure limiting means 4 can then be housed in one of said gripping tabs 24.

Such a compact arrangement advantageously makes it possible to integrate the pressure-limiting means 4 with the implantable device 1 without significantly increasing the bulk of the latter or hindering the placement of the gastric band during the implantation surgical procedure.

According to another variant embodiment illustrated in FIGS. 3 to 5, the pressure-limiting means 4 may be located on the catheter 10 which connects the implantable site 7 to the gastric ring. Preferably, it is possible to implement a particularly simple manner a lip valve at the level of of said catheter 10 by making an incision, preferably substantially longitudinal, in the thickness of a flexible tubing section of said catheter 10. As shown in Figure 3, the thus split section of the catheter 10 may be wrapped with a flexible and porous membrane that forms the retention pocket 12.

Preferably, the pressure limiting means 4 according to the invention is located in the immediate vicinity of the inflation chamber 2. Thus, it is possible to regulate the pressure in the inflation chamber 2 substantially at the level where said pressure produces its effects, which allows a fine control of the behavior of the device 1, at its functional area.

According to an alternative embodiment, the exhaust member 11 and the retention pocket 12 may however be placed upstream of the catheter 10, near the implantable site 7 and at a distance from the gastric ring, so as not to weigh down. said gastric band nor drive it down after implantation.

Although it has been described primarily with reference to a gastric constriction ring, the present invention is in no way limited to this single application.

It may in particular be adapted to an intragastric balloon intended to be introduced into the stomach to occupy part of the volume.

As is well known to those skilled in the art, such an intragastric balloon may be formed of one or more flexible bags forming one or more inflation chamber 2, the volume of which may be adjusted by injection or withdrawal. of inflation fluid. Generally, said balloon comprises a valve intended to be connected to an inflation means for conveying the inflation fluid from a reservoir to the inflation chamber 2.

According to an alternative embodiment not shown, such an intragastric balloon may advantageously be provided with a pressure limiting means 4 according to the invention comprising an exhaust member 11 integrated in the structure of the balloon and opening to the outside balloon, preferably substantially opposite the valve.

The operation of a device 1 according to the invention will now be briefly described, with reference to a gastric ring such as that shown in Figures 1 and 3.

The device 1 according to the invention is first introduced into the body of the patient.

For this purpose, the practitioner makes an incision in order to access the abdominal cavity of the patient into which he introduces the unwound tape. It then forms a loop surrounding the stomach by closing said strip on itself with the closure means 6.

The practitioner also positions the implantable site 7 under the skin of the patient and connects said implantable site 7 to the gastric band by means of a flexible catheter 10.

After implantation of the device 1, the practitioner inflates the inflation chamber 2 by injecting therein an inflation fluid. To do this, it first connects to the device 1, preferably by introducing a hollow needle through the septum 8, a pressure injection system, such as a syringe, and then propels the inflation fluid to inside the inflation chamber 2, via the implantable site 7 and the catheter 10.

The expandable wall 3 then deforms under the motor effect of the inflation fluid, and more precisely the filling pressure which tends to repel it, until the inflation chamber 2 reaches the desired functional volume.

If, during the injection, for example following a too strong gesture of the practitioner on the syringe, the filling pressure exceeds the critical pressure P _c , the exhaust member 11 passes from its closure configuration to its configuration of opening by creating a leak which allows the inflation fluid to escape from the inflation circuit 2, 7, 10.

Thus, the excess of inflation fluid responsible for the overpressure is spontaneously and immediately evacuated by the pressure-limiting means 4.

When the overflow of inflation fluid has been evacuated and the pressure in the inflation chamber 2 becomes lower than the critical pressure P _c , the exhaust member 11 returns to the sealed configuration so as to maintain in the inflation circuit 2, 7, 10, and more particularly in the inflation chamber 2, an amount of inflation fluid and a filling pressure sufficient for the device 1 to perform its normal operation.

Thus, the pressure relief means 4 according to the invention can advantageously fulfill the role of a safety valve which ensures that the pressure prevailing in the inflation chamber 2 at no time exceeds a critical pressure value P _c beyond which Irreversible damage could occur both in device 1 and in tissues or organ functions of the patient.

In a particularly advantageous manner, the fact of evacuating the excess inflation fluid out of the inflation circuit 2, 7, 10 makes it possible to avoid any saturation of the latter and any harmful overpressure whatever the quantity of inflation fluid actually introduced and / or the injection pressure exerted by the practitioner at the injection system. In other words, the pressure limiting means 4 according to the invention advantageously allows the practitioner to perform his injection "blind" without risk of degrading the device 1 or injure the patient since the pressure regulation is automatic.

When a retention pocket 12 is associated with the exhaust member, the excess inflation fluid is first expelled from the inflation circuit 2, 7, 10 to said retention pocket. This first transfer of fluid can be rapid in order to immediately absorb the pressure shocks which can suddenly appear under the effect of a force injection of the inflation fluid into the inflation chamber 2. The inflation fluid collected in the pocket retention then migrates gradually through the porous membrane which delimits the latter and disperses in the tissues surrounding the exhaust member 11. Thus, any risk of injury due to a sudden burst of the inflation fluid under pressure at a point very localized tissues of the patient is avoided, as well as any parasitic movement of the device 1, according to the action-reaction principle, during the ejection of the fluid.

Thus, the device according to the invention advantageously makes it possible, by means of a pressure relief means 4 of simple and compact design, to inject the inflation fluid in a particularly safe manner. since the device 1 according to the invention is able to automatically regulate the pressure in the inflation chamber 2.

Advantageously, the device according to the invention has in particular an excellent tolerance vis-à-vis possible handling errors that may occur during the inflation fluid injection phases, which makes its implementation particularly reliable and easy.

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

- Implantable medical device (1) comprising at least one inflation chamber (2) whose volume is modifiable by injection or withdrawal of an inflation fluid, characterized in that it comprises a pressure limiting means (4) for implanted within the patient and provided with a reversible escapement member (11) adapted to allow the flow of excess inflation fluid from the inflation chamber (2), said exhaust member (11) ) being arranged to alternately adopt a closure configuration in which it prevents the passage of the inflation fluid when the pressure prevailing in said inflation chamber (2), called "filling pressure", is less than or equal to a predetermined value, so-called "Coke pressure" (P _c ), and an opening configuration in which it allows the passage of the inflation fluid when the filling pressure exceeds said critical pressure (P _c ), so as to maintain the filling pressure substantially below the critical pressure (P _c ) at least when injecting the inflation fluid into said inflation chamber (2).

- Device according to claim 1 characterized in that the exhaust member (11) is designed to be able to communicate the inflation chamber (2) with the outside of the device (1) to evacuate at least in part the inflation fluid to the outside of the device in the tissues surrounding said exhaust member (11).

- Device according to claim 1 or 2 characterized in that the exhaust member (11) is associated with a retention pocket (12). 4 - Device according to claim 3 characterized in that the retention pocket (12) is delimited by a porous membrane for slow diffusion of the inflation fluid through the tissues surrounding the exhaust member (11).

5 - Device according to one of the preceding claims characterized in that it comprises an operation indicator designed to indicate to the practitioner that the pressure limiting means (4) has tripped.

6 - Device according to claim 3 or 4 and claim 5 characterized in that, the retention pocket (12) being deformable under the constraint of the inflation fluid discharged by the exhaust member (11), the operating indicator comprises a radio-opaque charge integrated in the structure of said retention pocket (12) which allows the practitioner to visualize the deformation of said retention pocket (12).

7 - Device according to one of the preceding claims characterized in that the pressure limiting means (4) comprises a calibrated valve (14).

8 - Device according to one of the preceding claims characterized in that the pressure limiting means (4) comprises a lip valve (20).

9 - Device according to one of the preceding claims characterized in that it constitutes an implantable device for the treatment of obesity.

10 - Device according to claim 9 characterized in that it constitutes a gastric ring for the treatment of obesity. - Device according to claim 10 characterized in that the gastric ring being provided with one or more gripping tabs (24) to facilitate its handling by the practitioner responsible for implantation, the pressure limiting means (4) is housed in one of said gripping tabs (24).

- Device according to claim 9 characterized in that it constitutes an intragastric balloon for the treatment of obesity.