FR2857851A1 - The use of a poly(D,L-lactide-co-glycolide) to produce an anti-adhesion screen on implants used during the surgical repair of ventral ruptures and hernias, especially abdominal wall hernias - Google Patents

Abstract

The use of a copolymer of poly(lactide-co-glycolide) to produce, within a prosthetic implant a screen with non-adhesion properties with respect to the biological tissues bordering a post-traumatic site and a prosthetic implant comprising such a screen. An independent claim is included for a method of fabrication of the multilayer prosthetic implant comprising the steps of (1) creating a membrane from poly(lactide-co-glycolide) as the main constituent; (2) coating the posterior face of the textile support with a solution of poly(lactide-co- glycolide) dissolved in a solvent; (3) lamination of the membrane onto the posterior face of the textile support in such a way that it is not deformed by the support and preserves a smooth appearance.

Description

PROTHETIC IMPLANT FORMING ANTI-ADHESION SCREEN USED

  PARTICULARLY IN THE FIELD OF PARIETAL SURGERY

  The present invention relates to the technical field of prosthetic implants used in particular in the field of parietal surgery.

  The present invention more particularly relates to a prosthetic implant intended to be implanted by conventional or laparoscopic surgical means for the treatment of hernias or eventrations.

  The invention also relates to a method of manufacturing a multilayer prosthetic implant.

  The invention also relates to a use of a poly (lactide-co-glycolide) copolymer.

  After surgery, including surgery at the abdominal region, adhesions may form between adjacent tissue surfaces, particularly between the parietal muscle wall and visceral tissues. Such adhesions can lead to chronic pain or serious complications with morbid risks of bowel obstruction or immobilization of organs when these adhesions are formed between two neighboring organs and prevent their respective movements.

  These undesirable effects occur particularly frequently after the implantation of a foreign body, for example a parietal reinforcement of the conventional type used for the treatment of hernias or eventrations. In this case, the adhesions are formed between the prosthetic implant and the visceral tissues. Thus, it may happen that an organ, for example a piece of intestine, adheres to a parietal reinforcement.

  It is already known to use medicinal substances, for example antibiotics, to prevent adhesions and postoperative infections. Such substances are applied, for example in the form of gels, directly to the post-traumatic sites and surrounding organs or tissues at the end of the surgical procedure. Although the use of such substances can significantly reduce the risk of adhesions, their use suffers from the fact that these substances degrade too quickly, and lose their properties too quickly, so that adhesions can still appear after some latent time and inflammatory tissue may form after surgery.

  It is also known to use synthetic bio-resorbable polymers in composite structures intended to treat hernias or eventrations, these structures comprising a non-resorbable part intended to be used as a reinforcement, and another bio-resorbable part intended to form a physical barrier between the implant and the surrounding tissues.

  On the other hand, such structures alone are often not sufficient to prevent the formation of adhesions between the implant and the surrounding tissues so that complications may occur after the surgical procedure. In particular, the formation of adhesions between the implant and the visceral tissues is often observed immediately after implantation, which can generate a risk of intestinal obstruction and / or impair the mobility of organs.

  In addition, the degradation of bio-resorbable synthetic polymers conventionally used, such as polycaprolactone-type polyesters, is often accompanied by a significant inflammatory or even proliferative reaction, itself capable of generating secondary adhesions. 4z

  To partially overcome these disadvantages, it is known to introduce within this composite structure, biological agents capable of preventing postoperative adhesions and the development of inflammatory tissue.

  However, the action of these agents is often difficult to control, and the method of integrating said agents into the composite structure is generally complex and expensive to implement.

  The objects assigned to the invention therefore aim at proposing a new prosthetic implant that does not have the drawbacks of the aforementioned implants, and that makes it possible on the one hand to prevent the adhesions effectively and continuously, in particular as soon as it is implanted, and on the other hand to limit the intensity of the inflammatory reaction.

  Another object of the invention is to provide a new prosthetic implant whose postoperative adhesion prevention properties are reinforced.

  Another object of the invention is to propose a novel implant minimizing the risks of postoperative inflammatory reaction.

  Another object of the invention is to propose a new implant whose therapeutic properties are improved.

  Another object of the invention is to provide a new implant 20 for accelerating the repair of trauma.

  Another object of the invention is to propose a new prosthetic implant that promotes cellular rehabitation.

  Another object of the invention is to propose a new prosthetic implant having a bio-adhesive character. t

  The objects assigned to the invention are also intended to provide a new method of manufacturing a prosthetic implant particularly simple and inexpensive to implement.

  Another object of the invention is to propose a new method of manufacturing a prosthetic implant that is fast and reliable.

  Another object of the invention is to propose a novel method for manufacturing a prosthetic implant that makes it possible to obtain good mechanical properties of the implant.

  The objects assigned to the invention also aim at proposing a new use of lactide and glycolide copolymers which is particularly advantageous in the fields of the prevention of postoperative adhesions and the limitation of the risks of inflammatory reaction.

  The objects assigned to the invention are achieved by means of a prosthetic implant characterized in that it comprises a substantially impermeable screen intended to be interposed between a post-traumatic site and the surrounding tissues to prevent said surrounding tissues from adhere firstly to said post-traumatic site and secondly to said implant, said screen comprising, as a majority component, a poly (lactide-co-glycolide) copolymer.

  The objects assigned to the invention are also achieved by means of a method of manufacturing a multilayer prosthetic implant characterized in that it comprises: a step (a) of producing a membrane from poly (lactide-glycolide) as the major component, a step (b) of coating the backside of a textile support with a solution of poly (lactide-co-glycolide) dissolved in a solvent, - a step (c) ) laminating said membrane on said posterior face of said textile support, such that said membrane is not deformed by the textile support and retains a substantially smooth appearance after being placed on said textile support.

  The objects assigned to the invention are also achieved by using a poly (lactide-co-glycolide) copolymer as the major component for producing, within a prosthetic implant, a screen having non-adherence properties with respect to biological tissues surrounding a post-traumatic site.

  Other objects and advantages of the invention will appear better on reading the attached description, and with the aid of the appended drawings, for purely illustrative and informative purposes, among which: FIG. 1 illustrates, according to a sectional side view, the schematic structure of a possible embodiment of a prosthetic implant according to the invention.

  - Figure 2 illustrates, in a side sectional view, the schematic structure of a second embodiment of a prosthetic implant according to the invention.

  - Figure 3 illustrates, in a side sectional view, the schematic structure of a third embodiment of a prosthetic implant 25 according to the invention.

  Figure 1 shows a prosthetic implant 1 according to the invention intended to be implanted in the body of a patient, in particular for the treatment of hernias or eventrations.

  The term "prosthetic implant" here refers to a prefabricated prosthesis intended to be introduced into the body of a patient. The implant within the meaning of the invention is thus particularly different from gels or lotions intended to be applied during surgical operations. According to the invention, the prosthetic implant is intended to cover a posttraumatic site, for example to strengthen it.

  Within the meaning of the invention, the prosthetic implant comprises a screen 2 substantially impermeable, that is to say substantially non-porous after its introduction into the body of the patient.

  The term "impermeable" here designates a particular property of the screen 2 preventing the penetration of cells through the screen 2 and therefore through the prosthetic implant 1, as soon as the implant is placed within the patient's body. .

  Advantageously, the screen 2 is intended to be interposed between the posttraumatic site and the tissues surrounding this site, that is to say the tissues located near the post-traumatic site, in order to prevent the latter from adhering. on the one hand on said post-traumatic site and on the other hand on the prosthetic implant 1.

  Within the meaning of the invention, the screen 2 comprises, as a majority component giving the screen 2 its anti-adhesion properties, a poly (lactide-co-glycolide) copolymer. The use of such a copolymer of poly (lactide-co25 glycolide) also makes it possible to limit the risk of an inflammatory reaction generally observed during the degradation of conventional bioabsorbable synthetic polymers such as polylactides or polycaprolactone.

  The term majority refers to the fact that, if the poly (lactide-co-glycolide) copolymer is combined with another component to form a mixture, the molar or mass proportion of said poly (lactide-co-glycolide) copolymer will be greater than the respective proportions of the other components. The term majority also refers to the fact that the poly (lactide-co-glycolide) copolymer can be used alone, without necessarily being mixed with another component.

  Advantageously, the poly (lactide-co-glycolide) copolymer is bioresorbable, so that such a material does not need to be removed from the body of the patient and does not require a posterior surgical procedure because it progressively degrades within the body.

  According to the invention, the proportions of lactide and glycolide in the copolymer will preferably be substantially equivalent, the copolymer may for example contain 50% moles of lactide and 50% moles of glycolide, and still more preferably 54% of moles of lactide and 46% moles of glycolide. Of course, variations of proportions may be allowed.

  According to a preferred embodiment of the invention, the lactide will be D, L-lactide, but it will also be possible to use L-lactide or Dlactide.

  According to the invention, the screen 2 is formed by a preferably non-fibrous membrane and having a substantially smooth surface. Such a membrane structure further contributes to improving the anti-adhesion properties of the screen 2. In particular, the smooth surface, unlike rough or rough surfaces, makes it more difficult to grip tissue or cells on the screen. the surface, and allows to limit their proliferation.

  Advantageously, the thickness of the membrane will not be too high, and will preferably be less than 300 microns so as to give some flexibility to the screen 2 facilitating its handling, and more generally to the prosthetic implant 1 .

  Of course, it is also conceivable to make the screen 2 with a lyophilizate of poly (lactide-co-glycolide). Such a lyophilizate has advantages such as improving the general mechanical properties of the screen 2. In particular, a screen 2 formed by a lyophilizate will be lighter than a similar screen formed by a membrane. It will also be a priori more flexible.

  The use of a membrane, however, remains preferred to that of a lyophilizate to make the screen 2, because of the high porosity of the lyophilisate 15 before it is placed in the body of the patient. Thus, such a lyophilizate could, in particular because of its irregular external appearance and its porosity, be substantially less effective, at least initially, in the prevention of adhesions on the one hand, and of the adhesion on the other hand and proliferation of inflammatory-like cells on and around the prosthetic implant 1.

  According to an even more preferred embodiment of the invention, the screen 2 is formed by a mixture of poly (lactide-co-glycolide) with polycaprolactone. Such a mixture, and in particular the addition of polycaprolactone, makes it possible to improve the mechanical properties of the prosthetic implant 1. t

  In a particularly advantageous manner, the proportion of polycaprolactone in admixture will preferably be lower than that of the poly (lactideco-glycolide) copolymer. The proportion of the two components will be determined in particular so that the addition of a small amount of polycaprolactone improves the flexibility and general flexibility of the screen 2, but does not alter its anti-adhesion properties too much.

  As an illustrative and nonlimiting example, the proportion of polycaprolactone mixture may be between 0 and 50% by weight, but will preferably be between 1% and 15% by weight.

  Advantageously, the screen 2 is progressively degraded after its implantation in the body of the patient, so that its average duration of resorption is preferably substantially between fifteen days and two months. Such a resorption time is desirable to allow sufficient regeneration of muscle tissue cells and in particular to allow the total recovery of the implant by a peritoneal cell layer capable of preventing any risk of adhesion.

  According to another embodiment of the invention, the screen 2 may also comprise a biocompatible plasticizer, of the glycerol type, capable of further improving the mechanical properties of the prosthetic implant 1.

  According to the invention, the prosthetic implant 1 also comprises a biocompatible textile support 3.

  Advantageously, the textile support 3 may be bioabsorbable, but it will preferably be non-bioabsorbable so that it remains in the body of the patient after the screen 2 is completely resorbed. The textile support 3 is preferably intended to constitute a reinforcement, and in particular a reinforcement capable of reinforcing the abdominal muscle wall.

  According to the invention, the textile support 3 comprises an anterior face 3A intended to be positioned vis-à-vis the post-traumatic site when the prosthetic implant is placed inside the body of the patient. In particular, the anterior surface 3A can be placed directly against the post-traumatic site so as to be in close contact with the latter. The textile support 3 also comprises a posterior surface 3B intended to be positioned vis-à-vis the tissues surrounding the post-traumatic site.

  Within the meaning of the invention, the posterior surface 3B is covered, preferably completely, by the screen 2, so that the latter is interposed between the surrounding tissues and the rest of the implant, in particular the textile support 3.

  Advantageously, the screen 2 is formed by the membrane which is placed on the textile support 3 by gluing or rolling or by any other means well known to those skilled in the art. The adhesive used may, of course, be silicone, but it will preferably be based on a copolymer of poly (lactide-co-glycolide) dissolved in a solvent, for example dichloromethane, so as to form a tacky solution which may be spread on the posterior face 3B of the textile support 3 so as to form a sticky film 4.

  Preferably, the adhesive film 4 will penetrate inside the textile support 3 so as to impregnate the fibers constituting it and create an intimate bond between the adhesive film 4 and the textile support 3.

  The screen 2 can then be deposited on the adhesive film 4 immediately after the application of the latter on the textile support 3 or, preferably, after the partial evaporation of said solvent, and then laminated so as to constitute the prosthetic implant. 1. Since the screen 2 is substantially of the same nature as the adhesive film 4, the cohesion between these two elements or layers is improved, which makes it possible to avoid the delamination of the screen 2.

  Preferably, the membrane forming the screen 2 will be substantially larger than the textile support 3 so as to be folded over the edges of the textile support 3, as shown in Figures 1 and 2.

  According to another embodiment of the invention, and as shown in FIG. 3, points of adhesive 3 are deposited, in a preferably uniform pitch, on the rear face 3B of the textile support 3.

  The screen 2 can then be deposited on the glue points 6 to be glued, so that a narrow space 7 is preferably formed between the screen 2 and the textile support 3. The glue points 6 then act in the manner of pads 10 to maintain a small gap between the screen 2 and the textile support 3, so that the latter two elements are not directly in contact.

  According to this particular embodiment of the invention, the membrane forming the screen 2 is preferably substantially larger than the textile support 3 15 so as to extend beyond the edges of said textile support 3.

  According to the invention, the textile support 3 comprises a two-dimensional or three-dimensional structure layer, which is woven, non-woven, knitted or braided.

  Advantageously, the textile support 3 is formed of yarns preferably selected from the group of single-strand polyester or multi-strand polyester yarns, or monofilament or multi-strand polypropylene yarns. Of course, it is also conceivable to make the textile support from polyamide or polybutester son, or from resorbable synthetic polymer fibers.

  According to a preferred embodiment of the invention, and as shown in FIG. 2, the prosthetic implant 1 also comprises a coating 5, which is deposited on the anterior face 3A of the textile support 3 so as to come in contact with the posttraumatic site.

  Within the meaning of the invention, the coating 5 comprises, as main compound, one or more components chosen from the group of substances or derivatives of the following substances: hyaluronic acid, alginates, collagen, polypeptides, polysaccharides.

  Such compounds have the particular property of promoting adhesion to biological tissues and in particular the tissues of the muscular walls.

  Advantageously, the coating 5 is a lyophilizate of the aforementioned substances, and even more preferably a lyophilizate of hyaluronic acid. The structure of the lyophilisate thus facilitates the attachment of the implant on the post-traumatic site so that it is not necessary to use other fastening means such as sutures or staples. or an adhesive glue for fixing the prosthetic implant 1 on the biological tissues.

  In a particularly advantageous manner, the prosthetic implant 1 thus comprises a textile support 3, intended to assume a reinforcing function, which is interposed between on the one hand a screen 2 intended to prevent adhesions, and on the other hand a coating 5 on the contrary, it is intended to promote the adhesion and attachment of the implant to the tissues and in particular to the muscular tissues.

  By way of illustrative and non-limiting example, such a prosthetic implant 1 may be used to form a prosthesis capable of treating eventrations or hernias of the abdominal wall.

  Preferably, the implant will be sterilized after manufacture, for example using radiation y.

  Means for fixing the prosthetic implant 1, for example cords, can be integrated in the latter, but it is preferentially the coating 5, and in particular the lyophilizate of hyaluronic acid, which promotes the adhesion of the implant on the muscle tissues, so that no additional fixation means is needed.

  The prosthetic implant according to the invention consequently has particularly advantageous mechanical properties, especially from the point of view of its resistance to mechanical stresses and in particular to shearing, which is reinforced by the intimate connection between the different layers of the implant. , its strength and finally its flexibility, which is improved by the spongy structure of lyophilisate and the flexible character of the screen or the membrane.

  Another advantage of the prosthetic implant according to the invention is that it has very good anti-adhesion properties, as soon as it is implanted in the body of the patient.

  Another advantage of the prosthetic implant according to the invention is that it limits the proliferation of inflammatory cells.

  Another advantage of the prosthetic implant according to the invention is that it has a very good flexibility, which allows it to conform to human tissues.

  The invention also relates to a multilayered prosthetic method comprising a membrane step from poly (lactide-co-glycolide), to form a non-stick screen 2.

  manufacture of an implant (a) for producing one as a component As an illustrative and nonlimiting example, the membrane may be made by dissolving the poly (lactide-co-glycolide) copolymer, for example under form solid beads using a solvent such as dichloromethane. The material is then stretched on a plate, for example a teflon plate, until complete evaporation of the solvent so as to form a membrane. It is of course possible to use a press to compress the solid beads or more generally the solid material based on poly (lactide-co-glycolide) and to stretch the latter to form a membrane.

  According to the invention, the method also comprises a step (b) of coating the posterior face 3B of the textile support 3 with a solution of poly (lactide-co-glycolide) dissolved preferably in the solvent. Such a solution acts in the manner of an adhesive. Of course, it is possible to replace this poly (lactide-co-glycolide) solution with an adhesive, for example of the silicone type.

  However, if dots of glue protrude from the implant tissue adhesions may occur between the prosthetic implant and the glue spots, so poly (lactide-co-glycolide) is preferable.

  In the sense of the invention, the method of manufacturing the multilayered prosthetic implant also comprises a step (c) of rolling the membrane on the posterior face 3B of the textile support 3. Step (c) is carried out in such a way that the membrane is not deformed by the textile support 3 and retains a substantially smooth appearance after being put in place. In particular, the pressure exerted respectively on the membrane and on the textile support 3 so as to bond them to each other should not be too strong so as not to degrade the membrane. The smooth appearance of the membrane is indeed particularly important and contributes to the non-adherence properties of the latter. Thus, a membrane having a rough appearance may tend to promote adhesions as well as the attachment and proliferation of inflammatory tissue cells.

  Preferably, the method of manufacturing the multi-layered prosthetic implant also comprises a step (d) prior to step (c) in which the solvent is evaporated at least partially, so as to form a sticky film 4 on the posterior face 3B of the textile support 3.

  The evaporation should preferably not be complete so that the adhesive film 4 is neither dry nor hard but substantially soft, at least on its outer surface.

  Advantageously, the method of manufacturing the prosthetic implant also comprises a step (e) of impregnating the textile support 3 with a solute.

  Preferably, the solute comprises, as a main compound dissolved in a suitable solvent, one or more compounds selected from the group of substances or derivatives of the following substances - hyaluronic acid, - alginates, - collagen, - polypeptides, - polysaccharides .

  Particularly advantageously, the process also comprises a step (f) of depositing a coating 5, said coating comprising the main compound of the aforementioned solute.

  Advantageously, the method also comprises a step (g) of lyophilization of the coating 5.

  Preferably, step (e) is carried out before step (b) while steps (f) and (g) are performed after steps (a), (b), (c) and (d). above mentioned.

  Thus, the textile support 3 is dipped in a bath, for example hyaluronic acid in solution, so as to impregnate it in accordance with step (e).

  After a drying phase of the textile support 3, the posterior face 3B of the textile support 3 is coated with the solution of the poly (lactidecoglycolide) dissolved, in accordance with step (b). The membrane is then mounted integrally on the textile support 3 to form a composite material formed by the membrane (or screen 2) and the textile support 3.

  It is then possible to proceed to the step (f) of depositing the coating 5 on the anterior face 3A of the textile support 3, then to the step (g) of freeze-drying said coating 5.

  Such a succession of steps is preferable for a coherent and logical implementation of the method.

  Of course, it is also conceivable to carry out steps (f) and (g) prior to steps (a), (b), (c) and (d) above.

  It is also possible to omit step (e) of impregnation, in which case steps (f) and (g) are carried out directly after steps (a), (b), (c) and (d).

  The invention also relates to a use of a poly (lactide-co-glycolide) copolymer, preferably as a majority component, for producing, in a prosthetic implant 1, a screen 2 having non-conforming properties. -adherence to biological tissues surrounding the post-traumatic site. In particular, the poly (lactide-coglycolide) copolymer preferably prevents adhesions with tissues adjacent to the post-traumatic site as soon as the prosthetic implant 1 is placed in the body of the patient. This avoids the initial formation of adhesions likely to generate the previously described complications.

  According to a preferred embodiment of the invention, the poly (lactide-co-glycolide) copolymer is used in admixture with polycaprolactone, so as to improve the mechanical properties of the screen 2. Thus, the addition of polycaprolactone improves the flexibility of the screen 2, and facilitate its handling, as well as that of the prosthetic implant 1. Such flexibility is particularly important in applications using a trocar 20 to set up the prosthesis.

  According to the invention, the screen 2 is constituted by a preferably non-fibrous membrane which has a substantially smooth surface.

  Such a use of a poly (lactide-co-glycolide) copolymer thus makes it possible to limit the formation of adhesions between tissues, and in particular the adhesion between the tissues surrounding a post-traumatic site and the prosthetic implant, and this, from the implementation of said prosthetic implant within the body of the patient.

  We will now describe some embodiments of prosthetic implants according to the invention, their mode of implantation, as well as their comparative performance.

  As a purely illustrative and nonlimiting example, the 5 samples are prepared in the following manner: the prosthetic implants are composed of a textile support formed by a polyester knitted fabric of dimension 2x3 cm. Prosthetic implants are covered on both sides with a lyophilisate of hyaluronic acid. The anti-adhesion screens, in the form of membranes made from the materials described in the following examples, are glued to prosthetic implants coated with hyaluronic acid using implantable silicone glue dots of the following type. NuSil 1511.

  These prosthetic implants are then implanted in rats each weighing approximately 300 g, the implantation being of intraperitoneal type.

  Subcutaneous implantation of anti-adhesion screens is also performed without the knitted fabric.

  In the case of intraperitoneal implantation, a median laparotomy is performed and a peritoneal orifice is created. The prosthetic implant is then positioned in contact with the abdominal muscle wall at the peritoneal orifice. The incision is then closed by suture.

  In the case of subcutaneous implantation, four paravertebral incisions are made and then the anti-adhesion screen tested is inserted into a stool created in the subcutaneous tissue, and the incisions are then closed with cutaneous staples. r r

  Prosthetic implants and screens are sterilized by radiation before intraperitoneal or subcutaneous implantation.

  After the preparation of the implants and their implantation in the rats, macroscopic observations and microscopic analyzes are carried out for each test carried out, and the results are presented in the examples which follow.

Example 1 (Witness)

  Prosthetic implants are made comprising a textile support provided with a hyaluronic acid coating but not comprising an anti-adhesion screen. These prosthetic implants are implanted intraperitoneally into rats.

  The rats are then sacrificed thirteen days after implantation of the prosthetic implant and important visceral adhesions are observed on the textile support.

Example 2

  In Example 2, a screen and a prosthetic implant with a poly (D, L-lactide-co-glycolide) membrane in proportions of 54 mol% of D, L-lactide and 46 mol% are prepared. of glycolide. The poly (D, L -actide-co-glycolide) used can be, for example, Purasorb PDLG from Purac Biochem. At fifteen days, macroscopic observations on the sacrificed rats show very weak adhesions and a membrane (or screen) of anti-adhesion during degradation. Microscopic observations, and in particular histopathological examination, reveal that the resorption reaction is not very inflammatory.

  At thirty days, the macroscopic observations show that the only points of adhesion are at the points of silicone glue. Again, the reaction is not inflammatory.

  At sixty days, peritonization is performed, no adhesion is visible and adipose tissue is non-inflammatory.

  In the case of the subcutaneous implantation of the screen, the observations also show a little inflammatory evolution, with a very little inflammatory tissue and very thin at thirty days.

  At sixty days, the screen is completely resorbed.

Example 3

  A screen and a prosthetic implant are made with a membrane based on poly (L-lactide), for example Purasorb PL from Purac Biochem. In the case of intraperitoneal implantation, the poly (L-lactide) screen is fissured at fifteen days, not resorbed, and has numerous adhesions.

  Microscopic observations show the formation of moderate inflammatory tissue.

  At thirty days, the film is still not resorbed, multiple adhesions are visible, and microscopic observations reveal a proliferative inflammatory reaction. t

  At sixty days, the adhesions are still present and the microscopic observations show a very thick inflammatory tissue revealing a very important inflammatory reaction.

  In the case of subcutaneous implantation, a haemorrhagic reaction is observed at thirty days and the screen is still not degraded at sixty days, although it is slightly cracked.

Example 4

  A prosthetic implant comprising a screen based on poly (D, Llactide), for example Purasorb PDL from Purac Biochem. At fifteen days, the poly (D, L-lactide) screen is fragmented and has numerous adhesions. Microscopic observations show a significant inflammatory reaction and in particular many fibroblastic cells.

  At thirty days, there are still many adhesions and microscopic observations show a proliferative inflammatory reaction.

  At sixty days, no adhesion is observed but the inflammatory reaction is very important. In addition, the screen is not degraded.

  In the case of subcutaneous implantation, the screen cracked gradually and at sixty days, the microscopic observations revealed traces of resorption with inflammatory reaction.

  The above-mentioned examples of embodiments are of course given only as a purely illustrative and non-limiting example.

Claims (18)

  1 - Prosthetic implant (1) characterized in that it comprises a substantially impermeable screen (2) intended to be interposed between a posttraumatic site and the surrounding tissues to prevent said surrounding tissues from adhering on the one hand to said post site and on the other hand on said prosthetic implant (1), said screen (2) comprising, as a majority component giving the screen (2) its anti-adhesion properties, a copolymer of poly (lactide-co- glycolide).   2- prosthetic implant according to claim 1 characterized in that said screen (2) is formed by a non-fibrous membrane and having a smooth surface.   3- prosthetic implant according to claim 1 characterized in that said screen (2) is formed by a lyophilisate.   4- Prosthetic implant according to one of claims 1 to 3 characterized in that said screen (2) is formed of a mixture of poly (lactidecoglycolide) with polycaprolactone.   5- prosthetic implant according to one of claims 1 to 4 characterized in that the copolymer of poly (lactide-co-glycolide) is made from D, L-lactide.   6- prosthetic implant according to one of claims 1 to 5 characterized in that it also comprises a biocompatible textile support (3) which comprises an anterior face (3A), intended to be positioned vis-à-vis said post-traumatic site and a posterior face (3B) intended to be positioned vis-à-vis said surrounding tissues, said tr face posterior (3B) being covered substantially completely by said screen (2).   7- prosthetic implant according to claim 6 characterized in that said textile support (3) comprises a two-dimensional or three-dimensional structure layer, said structure being woven, non-woven, knitted or braided.   8 - prosthetic implant according to claim 6 or 7 characterized in that said textile support (3) is formed of son selected from the group of son - polyester monocrine or stranded, 10 - son polypropylene monobrin or stranded.   9- prosthetic implant according to one of claims 6 to 8 characterized in that it also comprises a coating (5) deposited on said anterior face (3A) of said textile support (3), said coating (5) comprising, as a that main component, one or more component (s) chosen (s) from the group of substances or derivatives of the following substances: - hyaluronic acid, - alginates, - collagen, - polypeptides, - polysaccharides.   10-prosthetic implant according to claim 9 characterized in that said coating (5) is a lyophilisate.   11-implant prosthetic according to one of claims 1 to 10 characterized in that it forms a prosthesis to treat eventrations and hernias, including hernias of the abdominal wall.   12 - A method of manufacturing a prosthetic multilayer implant according to claim 2 and to one of claims 4 to 11 characterized in that it comprises: - a step (a) of producing a membrane from poly (lactide-co-glycolide) as a major component, - a step (b) of coating the posterior face (3B) of a textile support (3) with a solution of poly (lactide-co-glycolide ) dissolved in a solvent, - a step (c) of rolling said membrane on said rear face (3B) of said textile support (3), such that said membrane is not deformed by the textile support (3) and 15 maintains a substantially smooth appearance after being placed on said textile support (3).   13-Process according to claim 12 characterized in that it comprises a step (d) prior to step (c) wherein said solvent is evaporated, at least partially.   14-Process according to claim 12 or 13 characterized in that it comprises a step (e) of impregnation of said textile support (3) with a solute comprising, as main compound, one or more compound (s) chosen ( (s) from among the group of substances or derivatives of the following substances: - hyaluronic acid, - alginates, collagen, - polypeptides, polysaccharides.   -Procédé according to claim 14 characterized in that it comprises a step (f) deposition of a coating 5 of said main compound on the anterior face (3A) of said textile support (3).   16-Process according to claim 15 characterized in that it comprises a step (g) of freeze-drying said coating (5).   17 -Utilization of a poly (lactide-co-glycolide) copolymer to produce, within a prosthetic implant (1), a screen (2) having non-adhesion properties with respect to the tissues surrounding a posttraumatic site.   18. Use according to claim 17, characterized in that said poly (lactide-co-glycolide) copolymer is mixed with polycaprolactone.   19-Use according to claim 17 or 18 characterized in that said screen (2) is constituted by a non-fibrous membrane and having a smooth surface.