EP3071157A1

EP3071157A1 - Implantable prosthetic device for weight loss in an obese or overweight patient including an inflatable gastric balloon and a duodenal prosthesis

Info

Publication number: EP3071157A1
Application number: EP14800040.9A
Authority: EP
Inventors: Gianfranco DONATELLI; Frédéric PRAT
Original assignee: Assistance Publique Hopitaux de Paris APHP
Current assignee: Assistance Publique Hopitaux de Paris APHP
Priority date: 2013-11-18
Filing date: 2014-11-18
Publication date: 2016-09-28
Also published as: FR3013212B1; US20170000636A1; WO2015071496A1; FR3013212A1

Abstract

The invention relates to a prosthetic device intended for being implanted in the digestive tract of a patient, said device comprising an inflatable gastric balloon (1) with modular volume and a duodenal prosthesis comprising a prepyloric flange (31) and a flexible tubular body (32). According to the invention, such a device is characterised in that said device comprises a system (2) for attaching said balloon to said duodenal prosthesis; said duodenal prosthesis is compressible and expandable in a radial direction; said prosthesis has a wall which is rigidly connected, on at least one portion of the length thereof, to a helical framework (33); and said helix has an irregular pitch.

Description

Implantable prosthetic device for weight loss in an obese or overweight patient comprising an inflatable gastric balloon and a duodenal prosthesis.

1. Field of the invention

The field of the invention is that of prostheses intended to be implanted in the digestive tract.

More specifically, the invention relates to a prosthesis intended to be implanted at the level of the digestive tract of a patient, the prosthesis comprising an inflatable balloon and adjustable for the stomach and a stent intended to be placed in the duodenum of the patient.

2. Prior Art

The World Health Organization (WHO) estimates that approximately one billion people are currently overweight worldwide, of which 300 million are said to be clinically obese with a Body Mass Index (BMI) greater than 30 kg / m

(WHO: http://www.who.int/dietphysicalactivity/media/en/gsfs_obesity.pdf).

Currently, it seems that the trend of these figures is growth.

The notions of obesity and overweight are commonly appreciated by the Body Mass Index (BMI) which is the ratio of weight in kilograms to the square of height in meters: BMI = mass (kg) / height (m) . A patient is considered overweight when his or her BMI is greater than or equal to 25. Obesity is declared when the BMI is greater than or equal to 30 and morbid obesity is determined for a BMI greater than or equal to 35 or 40.

Obesity and overweight have various etiologies and are also sources of various problems: joint disorders, shortness of breath, difficulty moving, excessive fatigue, nervous breakdown due to a bad self-image, feeling of rejection by society etc. Besides these problems, Obesity and overweight are important risk factors for the patient's health, especially for cardiovascular diseases, hypertension, certain forms of cancer and type 2 diabetes. In addition, the management of these patients and their pathologies account for about 2-7% of health system spending for developed countries. Therefore, Obesity and overweight have become public health problems on a global scale.

Type 2 diabetes, also commonly referred to as acquired diabetes or diabetes mellitus, is non-insulin-dependent, ie it is not due to a lack of insulin production by the islets of Langerhans from the pancreas or by producing non-active insulin. Type 2 diabetes is due to the fact that, under the effect of excessive stimulation, the pancreas produces more and more insulin until the cells are depleted. When the amount of insulin produced is no longer sufficient to regulate the patient's blood glucose, the patient is in hyperglycemia. Many years can separate the onset of illness and the appearance of the first symptoms. A steady increase in blood sugar levels leads to glucotoxicity. This glucotoxicity is itself an aggravating factor of type 2 diabetes and cardiovascular disease. Type 2 diabetes can also be characterized by microangiopathic and macroangiopathic lesions of the pancreas.

Currently, the standard treatment for obesity and overweight is primarily surgical, the goal being to speed up and help the patient lose weight quickly. It is of course necessary to treat the patient in the long term by treating the causes of his overweight or obesity for example by teaching him to change his lifestyle and / or accompanying him on the psychological level. However, it is still necessary to quickly lose weight to the patient in order to limit the patient's risk of developing a cardiovascular pathology, to make a heart attack or the extent of the pathologies that have begun to develop. It is also necessary to quickly normalize your diabetes.

These surgical treatments are of two types:

- the restriction of the stomach, an intervention referred to as "vertical gastroplasty" or "sleeve gastrectomy" in English; or

- the pyloric shunt which consists of "connecting" a part of the stomach directly to the small intestine in order to limit the absorption of food, a procedure also known in English as "bypass". The restriction of the stomach can be done by different surgical procedures. For example, a gastric ring is known which is an implantable device that regulates the influx of food into the stomach. A gastric ring is in the form of a buoy that the surgeon inflates by injecting a little liquid regularly. Rings can be a source of pain or discomfort. The presence of a gastric band is also very restrictive for the patient: it is no longer possible to drink while eating, food intake must be very small and divided throughout the day, it is no longer possible to do contact sports, food must be cut very thin, it is necessary to chew a long time ... In addition, blockages of the ring can occur when the food is a bit too big to pass through the hole. Finally, in 10% of cases, it was found that the gastric band, originally placed outside the stomach at the level of the gastrooesophageal junction, migrates through the wall of the stomach to end up in the lumen of the stomach. the stomach. In other words, the ring is incarcerated in the gastric tissue and passes through the tissue so as to be partially in the light. This incarceration is accompanied by lesions, perforation of the tissue, inflammation or even partial necrosis in the injured area. The removal requires a very heavy operation for the patient and extremely delicate because it is a question of extricating the ring of the tissue, to remove the injured parts and to sew the tissues.

Therefore, although the gastric band allows good weight loss in patients, this device can cause significant complications and can be very poorly lived by the patient.

Tubular gastrectomy, or sleeve gastrectomy, which consists in reducing the volume of the stomach by stapling the vertical wall of the stomach longitudinally to keep only a narrow tube (calibrated on a probe). during the intervention). The excess part of the stomach is then removed.

The stomach shunt, or "bypass" in English, is to reduce the volume of the stomach by isolating a small pocket located in the upper part of the stomach by stapling. The majority of the volume of the stomach is no longer in communication with the esophagus. This small insulated pouch is then directly connected to a loop of the small intestine, which limits the absorption of food by shunting part of the small intestine. This procedure provides faster and more complete weight loss than with a gastric band (KSGersin et al., Gastrointestinal Endoscopy 2010, 71 (6): 976-982). However, because of malabsorption, patients are often deficient and vitamin supplementation for life is necessary.

Following these interventions, it was found that patients with type 2 diabetes, when they lose weight or benefit from such interventions, have their diabetes problem resolved spontaneously, diabetes can be reversible through loss. weight. The risks of developing cardiovascular pathologies also decrease (A. Genco et al., Obes, Surg., 2013, 23: 515-521).

However, since diabetes treatments are lifelong, adherence to treatment decreases over time. It is then necessary to follow the patient regularly. In addition, not all patients can be operated and some, fearing anesthesia, refuse to undergo a heavy intervention. Finally, these treatments are not free of risk themselves and may be accompanied by a feeling of discomfort or pain.

Prosthetic devices, implantable endoscopically, have been devised to overcome the risks of general anesthesia and surgery.

A first type of device is the intragastric balloon which is a pocket whose volume is adjustable by the surgeon. The balloon partially filling the stomach, the apparent volume of the stomach is reduced and the patient feels satiety more quickly. This treatment is effective. However, some complications can occur: it happens that the acidity of the stomach damages the material of the balloon and that the balloon is pierced and deflated gradually. Some studies have notably reported a balloon migration rate of about 7% (A. Genco et al., Obes, Surg., 2013, 23: 953-958).

A recent development offers treatment to obese or overweight patients who can not or do not want to undergo heavy surgery: it is the EndoBarrier®. EndoBarrier® is an endoprosthesis in the form of a flexible silicone sleeve with a pre- pyloric. The flexible sleeve is used to line the inside of the pylorus and duodenum. The prepyloric collar is a conventional metal prosthesis collar, comprising small metal hooks on its outer periphery. These hooks anchor the collar in the inner lining of the stomach to keep the EndoBarrier® in place and prevent migration. The food passes from the stomach through the prosthesis, the silicone sleeve to prevent the absorption of food by the pylorus, preventing contact between food and the intestinal wall.

Although effective, this technique is not without drawbacks. The first problem is related to the migration of the prosthesis. Sometimes the hooks come off the wall of the stomach. The prosthesis then tends to migrate into the digestive tract of the patient, under the effect of bowel movement and intestinal peristalsis. Another disadvantage encountered with the EndoBarrier® is related to the presence of hooks and their attachment in the inner wall of the stomach. It happens that the wall of the pylorus is perforated by the hooks located on the prepyloric collar of the prosthesis which causes pain, bleeding, infection (formation of abscesses) and a risk of peritonitis, whose outcome can be fatal. Another risk associated with the use of EndoBarrier® is related to the flexibility of the silicone sleeve. It often happens that the sleeve twists, closing the passage of food. There is therefore a phenomenon similar to that of intestinal obstruction, which requires rapid operation of the patient. Finally, some patients have poor support for the presence of the prosthesis and complain of pain requiring removal of the prosthesis (R.Schouten et al., Annals ofSurgery, 2010, 251 (2): 236-243).

Finally, surgical procedures require general anesthesia with intubation of the patient lasting between 1-3 hours, or even 5 hours in case of complications.

3. Objectives of the invention

The invention particularly aims to overcome these disadvantages of art eur.

In particular, an object of the invention is to provide, in at least one mode embodiment, a device for obese or overweight patients who can not or do not want to be operated on.

More specifically, an object of the invention is to provide, in at least one embodiment, a prosthetic device intended to be placed in the digestive tract of a patient to promote the weight loss of a patient.

Another object of the invention is to implement a prosthetic device allowing, in at least one embodiment, to treat type 2 diabetes or at least to limit the development of type 2 diabetes.

The invention also aims to propose, in at least one embodiment, such a device that is easy to implement.

The invention also aims, in at least one embodiment, to provide a prosthetic device that does not require general anesthesia with intubation or heavy surgery for its implantation in the body of a patient.

4. Presentation of the invention

These objectives, as well as others that will appear later, are achieved with the aid of a prosthetic device intended to be implanted in the digestive tract of a patient, said device comprising:

an inflatable gastric balloon whose volume is adjustable;

a duodenal prosthesis comprising a pre-pyloric collar and a flexible tubular body.

According to the invention, such a device is characterized in that it comprises a system for attaching said balloon to said duodenal prosthesis, in that said duodenal prosthesis is compressible and expandable in a radial direction and in that said prosthesis has a wall which is secured, for at least a portion of its length, to a helical frame.

The originality of the invention is twofold:

the system for attaching the duodenal prosthesis to the balloon makes it possible to limit or even avoid the risks of migration, perforation and infection; and the helical reinforcement of the duodenal prosthesis makes it possible to avoid intestinal obstruction by keeping the tubular body constantly open while having a radial deformability of the prosthesis in order to facilitate insertion and removal by endoscopy.

The device according to the invention therefore makes it possible to combine the effects of restriction of gastric volume and malabsorption in order to accelerate the weight loss of the patient. This rapid weight loss firstly makes it possible to slow down or stop the development of a beginning pathology or at the very least to reduce the probabilities of development of a pathology. For example, this rapid weight loss helps to stabilize type 2 diabetes or, when the patient is treated in time, to reverse the development of type 2 diabetes. other dysfunctions such as high blood pressure, sleep apnea etc.

The attachment system connecting the duodenal prosthesis to the balloon avoids the presence of hooks at the prepyloric collar. The absence of a hook at the prepyloric collar prevents the prosthesis from becoming fixed in the inner wall of the stomach. The risks of perforation and infection are avoided. It is also understood that the duodenal prosthesis being attached to the gastric balloon, and the balloon when inflated by the surgeon having a diameter greater than that of the pylorus, the risks of migration are avoided, or at least considerably limited.

The helical frame of the prosthesis keeps the tubular body open. The prostheses of the prior art have a flexible tubular body without a structure, such as a sock. Under the influence of intestinal peristalsis and the flow of food, this body tends to wrinkle and twist, so that the passage of food and gas is completely blocked. This phenomenon is similar to that of intestinal obstruction. This results in pain and vomiting. The helical armature integral with the wall of the tubular body keeps it open. It allows the tubular body to withstand the mechanical stresses that are exerted on it. The risk of occlusion is thus avoided, or at least greatly limited. Another advantage provided by the invention is that it is not necessary to intubate the patient during general anesthesia, and it is possible to reduce the anesthesia time. In addition, the rapid weight loss allowed by the device according to the invention is accessible to the strongest patients, for example those whose BMI is greater than or equal to 60,

Preferably, the helical reinforcement is integral with the wall of the tubular body. The outer wall of the tubular body is defined as the wall in contact with the intestinal tissue. The inner wall is the wall in contact with the food bowl. The helical frame may be either integral with the inner wall of the tubular body, or the outer wall of the tubular body, or be included in the wall. Preferably, the helical reinforcement is integral with the inner wall or included in the wall. Thus, it avoids contacting the helical armature with the intestinal wall, which avoids friction. More preferably, the helical reinforcement is included in the wall of the tubular body. The wall of the tubular body may be thin and its thickness may be less than or equal to 1 mm.

The helical framework of the duodenal prosthesis also allows the device according to the invention to be deformable in a radial direction, that is to say that the device according to the invention can be constrained in a catheter in order to be able to be placed and removed by endoscopy. The radial direction is appreciated relative to the axis of the prosthesis, which is parallel to the axis of transit of food through the prosthesis.

Endoscopy avoids heavy and prolonged general anesthesia that is at risk in patients with weakened cardiovascular and respiratory systems, as is the case with some obese or overweight patients. Endoscopy also avoids deep incisions, which are long to heal and painful, and can be infected or accompanied by hernias. Finally, endoscopy is a fast technique, well controlled and more reassuring for the patient.

This device can be offered to any type of patient, be it obese or overweight. More exactly, this device can be proposed to a patient whose BMI is greater than or equal to 30, if he suffers from type 2 diabetes. Preferably, the implantation time of the device according to the invention within the tube digestive of a patient is between 4 months and 12 months, preferably between 6 months and 12 months. The device according to the invention is therefore intended to be removed and must not be implanted for the entire life of the patient. It is therefore a temporary or temporary device.

More exactly, the device according to the invention can be proposed to patients with a BMI greater than or equal to 30, as soon as they show signs of comorbidity (high blood pressure, sleep apnea, shortness of breath, pre-diabetes ... ) and can be systematically offered to patients whose BMI is greater than or equal to 35. It should be noted that currently, the devices of the prior art are systematically only available to patients with a BMI of 40 or a BMI. greater than 35 with comorbidity. The device according to the invention therefore makes it possible to widen the category of patients who can benefit from it.

Advantageously, the pitch of the helix of said helical frame is irregular. "Propeller pitch" is the value of the displacement of the generator of the propeller along its axis in one turn. The irregularity of the pitch of the helix makes it possible to confer a degree of flexibility on the duodenal prosthesis so that it can bend sufficiently to adapt to the anatomy of the digestive tract of the patient.

Preferably, said pitch of the helix is increasing, from the prepyloric collar to the distal end of the tubular body. By end or "proximal" part is meant the end or part of the device which is on the side of the mouth. The end or "distal" portion of the device refers to the end or portion of the device that is closer to the anus. In other words, the helix forming the armature starts from the prepyloric collar. The pitch of the helix may be low so that the collar is stiffer than the rest of the duodenal prosthesis. In a first variant of the invention, the pitch of the helix may then gradually increase in order to confer more and more flexibility to the tubular body. In a second variant, the pitch of the helix at the tubular body may be different from that at the prepyloric collar but being regular all along the tubular body.

Advantageously, the duodenal prosthesis is devoid of hooks that allow it to be attached to the patient's digestive tissue. This feature avoids, or at least limits, the risk of perforation and hemorrhage of the gastric wall and therefore it also reduces the risk of bleeding and infection associated with it. A perforation is a surgical emergency. This feature also facilitates the removal of the device according to the invention.

In an advantageous embodiment, the attachment system is irreversible. Thus, it is easy to remove the device according to the invention by catching, by superior endoscopic approach, the deflated gastric balloon and remove the whole at one time. This characteristic also makes it possible to further limit the risks of migration of the prosthesis into the digestive tract.

In a particularly advantageous embodiment, the attachment system makes it possible, when pulling on the attachment system during removal of the gastric balloon, to cause the retraction of the prosthesis.

Preferably, the attachment system comprises irreversible fastening means. Such means may be chosen from a clip system, spring clips, an interlocking system, a harpoon-catheter couple, a ring associated with an endoscopic clip, etc.

In an advantageous embodiment, said helical armature extends over a portion of the total length of the duodenal prosthesis of between 50% -85%, preferably 75%. Preferably, the helical framework extends from the pyloric bulb to the first jejunal loop.

Preferably, the helical armature extends from the proximal end of the prepyloric collar. Thus, the distal portion of the tubular body of the duodenal prosthesis is left free, without helical reinforcement. Although this distal portion of the tubular body does not include helical reinforcement, the length left free is not sufficient to twist and seal the intestine. Preferably, the length of the tubular body not comprising helical reinforcement does not exceed 15 cm and more preferably does not exceed 10 cm. It has indeed been found by the inventors that these lengths do not allow the flexible tubular body to irreversibly twist. In other words, this free part of the tubular body, without helical reinforcement, is too short to cause occlusion. In an interesting embodiment, the inflatable gastric balloon and / or the duodenal prosthesis consist entirely or partially of a biocompatible material such as silicone, polyurethane, nylon, polyvinyl chloride, urethane, polyamide , the polyester, or the combination of at least two of these materials ...

These materials have the advantage of being well tolerated by patients, of resisting the environment of the digestive tract and of being resistant to sterilization and mechanical stress. Preferably, the gastric balloon and / or the duodenal prosthesis are made of silicone. More preferably, the gastric balloon and / or the duodenal prosthesis are entirely made of the same material.

Advantageously, said helical frame is made of a biocompatible metallic material, preferably an alloy of nickel and titanium. These materials have the advantage of being well tolerated by patients. In addition, they are particularly resistant to the surrounding acid-base environment, and constant contact with partially digested food. Moreover, these metals, or alloys, make it possible to produce shape memory materials. They are therefore particularly interesting for the design of expansive and compressible prostheses. More particularly, thanks to this type of material combined with the helical reinforcement, the prostheses can be compressed in a catheter that is introduced through the natural cavities of the patient. These prostheses are delivered at the site of the junction of the pylorus and the proximal portion of the duodenum, on a guide wire, under endoscopic and radioscopic control. The release of the prosthesis in the lumen of the digestive tract results in an immediate deployment thereof. This deployment is enabled by the use of a shape memory material, which means that the prosthesis returns to its original expanded form when the stresses exerted by the catheter disappear.

In an advantageous embodiment, the gastric balloon further comprises an inflation catheter. The inflation catheter is provided in the upper part of the balloon, said upper part of the balloon being that directed towards the esophagus. The inflation catheter, about 30-50 cm long, allows the volume of the balloon to be varied. Thus it is possible to gradually inflate the balloon so that the patient gradually gets used to the device and the changes in its diet that it induces. It can also be deflated slightly if the presence of the balloon causes discomfort for the patient. Finally, inflating or deflating the balloon facilitates the installation and removal of the balloon.

5. List of figures

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment, given as a simple illustrative example, and the appended drawings in which:

- Figure 1 shows a diagram of an embodiment of the device according to the invention implanted in the digestive tract of a patient; and

FIGS. 2A and 2B show transverse and schematic views of various embodiments of an irreversible fastening system according to the invention.

6. Description of an embodiment of the invention

The device according to the invention proposes to combine the effectiveness of an inflatable gastric balloon with that of a duodenal stent. The device according to the invention, however, comprises a system for attaching the duodenal prosthesis to the balloon in order to limit the risks of migration of the prosthesis and the gastric balloon. This feature also eliminates the need for hooks which avoids the risk of perforation of the gastric wall during the life of the prosthesis in the digestive tract and at the time of removal of the device. The device according to the invention also makes it possible to overcome in part the disadvantages of current stents by joining the wall of the duodenal prosthesis to a helical reinforcement over all or part of the length of said prosthesis. The helical frame not only provides flexibility and anatomical adaptation to the prosthesis but also allows to keep the tubular body open to avoid the phenomenon of occlusion caused by the torsion of the tubular body.

With reference to FIG. 1, an embodiment of the device according to the invention is presented when it is implanted and deployed in the digestive tract of a patient. patient being an obese patient (BMI greater than 30) or overweight (BMI greater than 25).

The device according to the invention comprises a gastric balloon 1 connected to a duodenal prosthesis 3 by an attachment system 2.

The gastric balloon 1 comprises an inflation catheter 4 and an attachment member 22. The inflation catheter 4 allows the surgeon to inject either air or a saline solution into the balloon to increase its volume. Preferably, the gastric balloon 1 is filled with air. It can also be filled with a colored liquid allowing the patient to identify any possible damage to the balloon early. The volume of the gastric balloon is flexible and can vary, when inflated, between 400 cm ³ and 750 cm ³ . Gastric balloon 1 has an outer wall, in contact with the stomach, and an inner wall in contact with air or saline. In this embodiment, the outer wall of the balloon 1 is made of silicone while the inner wall is made of polyurethane metallized with gold. The inflation catheter 4 comprises at its end 4 a closing means 41, such as a unidirectional valve, to prevent the air or the liquid contained in the balloon leaking into the patient's stomach. It also removes some air or liquid if the patient feels discomfort. It also allows to add a little air or liquid to vary the volume of the balloon gradually, to allow time for the patient to get used to the dietary changes that the installation of such a device involves.

The attachment system 2 comprises an element 21 integral with the balloon 1, an element 23 integral with the duodenal prosthesis 3 and securing means 22. The elements 21 and 23 may take the form of a fine catheter whose diameter is included between 2 and 5 mm, preferably about 3 mm.

Preferably, the securing means 22 are irreversible. These means may be constituted by each of the ends of the elements 21 and 22.

FIGS. 2A and 2B show various embodiments of an irreversible fastening system according to the invention.

FIG. 2A shows a cross-section of a first embodiment corresponding to a harpoon-catheter system. In this first variant, the end of the element 21 may take the form of a harpoon inserted in in the element 23. As shown, the catheter 21 comprises at its end a tip 221 shaped rounded tip and two barbs 222.

The inside of the catheter 23 comprises at its end a hook structure

223 on its inner periphery. Thus, when the tip 221 enters by elastic deformation in the catheter 23 through the structure 223, the barbs 222 are housed in the channel 224 and are retained by the structure 223.

FIG. 2B presents a second embodiment of the hanging system

2 with an interlocking system. In this embodiment, the element 21 may comprise one or more flanges 226 on its outer periphery intended to cooperate with one or more internal peripheral grooves 225 present at the element 23. One skilled in the art will understand that it is possible to reverse the characteristics of elements 21 and 23.

The attachment system 2 makes it possible to avoid the migration of the duodenal prosthesis 3 into the digestive tract, it being understood that the inflated gastric balloon can not pass through the pyloric sphincter SP. It also facilitates removal of the device according to the invention from the digestive tract of the patient.

The duodenal prosthesis 3 has a substantially tubular shape: it comprises in its proximal portion a prepyloric collar 31, a tubular body 32 and a distal portion 34. The duodenal prosthesis 3 is made of a biocompatible material, preferably non-biodegradable such as silicone , nylon or polyurethane, which gives it great flexibility and prevents food from being absorbed in the duodenum.

The prosthesis 3 also comprises a helical frame 33 secured to the wall of the prosthesis. The helical structure gives the prosthesis 3 its deformability in a radial direction, so that the prosthesis 3 can be constrained in a catheter during its endoscopic placement and that the withdrawal of the endoscopy catheter allows its immediate deployment, leaving the prosthesis 3 in intimate contact with the inner wall of the digestive tract.

The helical frame 33 also gives flexibility to the prosthesis so that it adapts on the one hand to the anatomy of the digestive tract, and resists on the other hand intestinal peristalsis. It also keeps the prosthesis open. In Indeed, the prostheses of the prior art, devoid of helical reinforcement, tend to crease and twist, to completely block the passage of food. The armature 33 integral with the wall of the prosthesis makes it possible to avoid such disadvantages.

The prepyloric collar 31 is intended to be deployed in the stomach at the level of the pylorus, upstream of the pyloric sphincter SP. Its diameter is between 25-35 mm, so that the diameter of the collar is greater than that of the pyloric sphincter and avoid migration of the prosthesis in the digestive tract. Preferably, the prepyloric collar 31 does not comprise any metal hook. Thanks to the attachment system 2, it is not necessary to provide hooks at the prosthesis so that it clings directly to the gastric tissue. Thus, the problems of irritation, perforation and infection are avoided, or at least greatly limited. The main body 32 of the prosthesis 3 has a constant diameter smaller than that of the flange 31, between 22 and 24 mm.

The total length of the prosthesis 3 can be between 40 cm and 70 cm.

Preferably, the helical reinforcement extends from the proximal end of the collar about 75% to about 85% of the total length of the prosthesis, being a length of between 30 cm and 60 cm. This implies that the distal portion 34 of the prosthesis is not secured to a helical frame about 10 cm. In other words, the distal portion 34 without armature is left free. The inventors have indeed found that this length was not sufficient to wrinkle or twist, and induce bowel obstruction.

In this embodiment, the pitch of the helix is irregular: it is low at the collar and the proximal portion of the prosthesis. It increases steadily along the tubular body.

As shown in FIG. 1, the gastric balloon 1 is released into the stomach E of a patient, at the level of the fundus under the esophagus O. The duodenal prosthesis 3 extends from the pylorus P and the The surgeon in vivo attaches the balloon 1 to the prosthesis 3 by the attachment system 2. 7. Variants

Other variants of the attachment system are conceivable. For example, it is possible to provide a ring on the prepyloric collar or that the catheter 23 ends with a loop. In this case, the catheter 21 will be terminated by a clamp enabling it to be fixed in the ring. In another variant, the catheter 23 is terminated by a clamp. When the clip is inserted into the catheter 21 by plastic deformation, the limbs of the clip once separate into the catheter 23 and exert a force against the inner wall of the catheter 23, preventing their exit.

Claims

A prosthetic device intended to be implanted in the digestive tract of a patient, said device comprising:

an inflatable gastric balloon (1) whose volume is adjustable;

a duodenal prosthesis (3) comprising a pre-pyloric collar (31) and a flexible tubular body (32);

characterized in that

said device comprises a fastening system (2) for said balloon (1) to said duodenal prosthesis (3);

said duodenal prosthesis (3) is compressible and expandable in a radial direction;

said prosthesis (3) has a wall which is secured, for at least a part of its length, to a helical reinforcement (33); and

said propeller has an irregular pitch.

The device of claim 1 wherein said pitch of said helix is increasing from the prepyloric flange (31) to the distal end of the tubular body (32).

Device according to one of the preceding claims wherein the duodenal prosthesis (3) is devoid of hooks.

Device according to one of the preceding claims wherein the fastening system (2) comprises irreversible fastening means (22).

An apparatus according to claim 4 wherein said irreversible securing means (22) is selected from a clip system, spring clips, a nesting system (225, 226), a spear-catheter system (221, 222, 223, 224).

6. Device according to one of the preceding claims wherein said helical armature (33) extends over a portion of the total length of the duodenal prosthesis (3) between 50% and 85%, preferably 75%.

7. Device according to one of the preceding claims wherein said gastric balloon (1) and / or the duodenal prosthesis (3) consist entirely or partly of a biocompatible material such as silicone, polyurethane, polyvinyl chloride , urethane, polyamide, polyester, nylon, or the combination of at least two of these materials.

8. Device according to one of the preceding claims wherein said helical frame (33) is a biocompatible metal material, preferably an alloy of nickel and titanium.

9. Device according to one of the preceding claims wherein the gastric balloon (1) further comprises an inflation catheter (4).