FR2953709A1 - Prosthesis for treating umbilical hernias, has ring that is fixed at peripheral outer edge of flexible circular lattice and maintains lattice in flat and unfolded configuration, where lattice is defined by peripheral outer edge - Google Patents

Abstract

The prosthesis (200) has a flexible circular lattice (1) defined by a peripheral outer edge. A reinforcement element reinforces the lattice, where the reinforcement element includes a semi-rigid and flexible ring (201) that is in the form of conical surface section. The ring is fixed at the peripheral outer edge of the lattice and maintains the lattice in a flat and unfolded configuration. The lattice includes a central part that is provided with a centering tire. The ring is made of bioresorbable material.

Description

The present invention relates to a prosthesis, for example intended for closing hernias, comprising a lattice and a reinforcing element of this lattice.

The abdominal wall in humans consists of fats and muscles connected to each other by fasciae. It sometimes happens that at the level of the aponeurosis a rupture of continuity forms, allowing a part of the peritoneum which then constitutes a sac, or a hernia, containing either fat or part of the intestines. Hernias or hernias (hernia occurring on a surgical parietal scar) are manifested by an outgrowth on the surface of the skin and are described as hernias or eventrations, for example, umbilical or inguinal depending on their location. In order to repair a hernia defect, surgeons frequently resort to the placement of a synthetic mesh prosthesis that replaces or strengthens the weakened anatomic tissues. However, such a prosthesis, once implanted, is subjected to abdominal pressure which tends to expel it to the outside. Such pressure can cause reversion of the prosthesis and the risk of recurrence of the hernia. Thus, the effectiveness of the prosthesis, and thus the minimization of the risks of relapse, depend to a large extent on the proper fixation of the prosthesis. In particular, before being fixed, the prosthesis must be correctly spread against the abdominal wall that it is intended to strengthen. Indeed, lattice-type prostheses, that is to say based on an arrangement of textile forming son, are generally flexible. To introduce them into the hernia orifice, they are often folded back on itself to diminish their volume. They therefore tend to form folds on the abdominal wall as they are introduced to the implantation site. In this respect, their spreading is essential, but it may be difficult, particularly in the case of the treatment of an umbilical hernia, which, being smaller than an inguinal hernia, offers little working space for manipulation of the prosthesis by the surgeon. For example, in the case of umbilical hernias, or when seeking to repair trocar holes, or in prevention, the size of the defect to be treated is small, for example 1 to 3 cm in diameter, and 35 It is possible to operate on an open lane. However, in this type of surgery, the surgeon has little work space and little visibility. It should therefore be possible to have a prosthesis that is easy to position, spread and fix, avoiding, if possible, having to suture the periphery of the prosthesis, a complicated and tedious operation under such working conditions.

Indeed, the lack of perfect spreading of the prosthesis against the abdominal wall carries a risk of engagement of the peritoneal sac and a risk of insertion of a soft organ between the prosthesis and the abdominal wall, which can lead to risk of adhesions, pain and bowel obstruction, and increase the chances of recurrence. It is therefore essential for the surgeon to ensure that no part of the prosthesis is folded and that no viscus or part of the intestines is interposed between the prosthesis and the abdominal wall. Furthermore, poor suture placement or poor fixation of the prosthesis may distort the prosthesis and create tension.

Thus, particularly in the case of an umbilical hernia having an insertion orifice of the small prosthesis, it would be advantageous to have a prosthesis can under stress occupy a reduced volume to facilitate its introduction into the abdominal cavity by said orifice, and then able to be deployed, spread and plated easily against the abdominal wall, or automatically without requiring significant manipulation of the prosthesis by the surgeon. There are different prostheses able to be folded on themselves and then deployed. It is known, for example from WO-A-00/07520, a prosthesis consisting of a flexible mesh reinforced by a double strapping provided with spokes. A wire passed to the periphery of the largest hoop allows to conform the prosthesis truncated cone at the time of introduction into the inguinal orifice. However, the spreading and plating of the prosthesis against the abdominal wall after introduction to the implantation site require significant intervention by the surgeon and are unsatisfactory. In addition, nothing is planned to prevent the risk of reversion of the prosthesis, once the latter implanted and subjected to abdominal pressure that tends to expel outwardly. The present invention relates to a prosthesis, able to be folded on itself at least in part to reduce the volume it occupies at the time of its introduction into a small incision and secondly, able to being spread out and fixed easily, said prosthesis being shaped so that the risks of reversion of said prosthesis are avoided, when once implanted, this prosthesis is subjected to the abdominal pressure which tends to expel it to the outside.

The prosthesis according to the invention is useful for the treatment of a hernia defect of the abdominal wall, in particular for the treatment of umbilical hernias for which the hernia defect is small. A first aspect of the present invention relates to a prosthesis comprising a flexible mesh defined by a peripheral outer edge, and a reinforcement element of said mesh, characterized in that said reinforcing member comprises at least one semi-rigid and flexible ring shaped of substantially conical surface section, said ring being attached at least to the peripheral outer edge of said lattice and maintaining said lattice in a substantially flat and spread configuration.

By "substantially conical surface" is meant in the sense of the present application a hollow structure having the overall shape of a cone or a dome, the dome or the cone being of revolution, pyramidal, ellipsoidal, any, for example built on a polygonal or square plan. For example, a structure in the form of a sugar loaf is also understood as a substantially conical surface within the meaning of the invention. The ring of the prosthesis according to the invention is defined by a section of such a surface, that is to say by a portion of the substantially conical surface, this portion being delimited by two parallel planes intersecting the cone or dome perpendicularly to the axis of revolution of the latter.

Thus, the ring of the prosthesis according to the invention has a certain height, corresponding to the distance separating the two parallel planes used to obtain the section defined above. Preferably, this height is from 1 to 7 mm, more preferably from 1 to 5 mm. Due to its flexible structure, the ring of the prosthesis according to the invention has a certain elasticity allowing it to deform under the effect of certain particular constraints and resume its semi-rigid configuration at rest after relaxation of these constraints. In the idle position of the ring, the lattice is held in a substantially flat and spread configuration.

By "lattice" is meant in the sense of the present application an arrangement of biocompatible son, such as knit, fabric, nonwoven, preferably perforated, that is to say provided with pores promoting tissue recolonization. Such a lattice may be bioabsorbable, permanent or partially bioabsorbable. It is generally flexible enough to be folded back on itself when introduced into the abdominal cavity. The lattice can be made of a layer of textile or of several layers. Such lattices are well known to those skilled in the art. The trellis that can be used according to the invention can be provided in any form, rectangular, square, circular, oval, etc., and then cut to fit the shape of the hernia defect. For example, the mesh may have a generally circular or oval shape: in such a case, the ring of the prosthesis according to the invention results from a section of cone or dome of revolution, elliptical or any. Alternatively, the lattice may have a generally square shape, or rectangular: in such a case, the ring of the prosthesis according to the invention results from a cone section or pyramidal dome.

As will become apparent from the description which follows, the prosthesis according to the invention is not subject to the phenomenon of reversion. Indeed, the semi-rigid ring keeps the plated prosthesis against the abdominal wall avoiding reversion of the prosthesis. In one embodiment, said lattice is attached to said ring over the entire height of said ring. The lattice may be fixed on the outer face of the ring, a portion of the lattice conforming to the surface of this outer face. Alternatively, the lattice may be fixed on the inner face of the ring, a portion of the lattice conforming to the surface of this inner face. In one embodiment, the central portion of said lattice is provided with at least one centering wire. Alternatively, several centering wires may be attached to the central portion of the mesh. In other embodiments, the centering wire (s) may be replaced by textile strips. This or these centering son or strips may for example be useful to the surgeon to facilitate the positioning of the prosthesis in the center of the defect to be treated and to bring the banks of the defect to be treated for suturing. In one embodiment, said ring is made of bioabsorbable material. For example, the bioabsorbable material may be selected from polylactic acid (PLA), polycaprolactones (PCL), polydioxanones (PDO), trimethylene carbonates (TMC), polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA) , oxidized cellulose, polyglycolic acid (PGA), copolymers of these materials and mixtures thereof. Alternatively, the ring is made of non-bioabsorbable material chosen from polypropylenes, polyesters such as polyethylene terephthalates, polyamides, silicones, polyetheretherketone (PEEK), polyaryletherketone (PAEK) and mixtures thereof. In one embodiment, the prosthesis is covered on its outer surface with a non-stick coating, particularly to prevent the formation of undesired severe post-surgical fibrous adhesions. For the purposes of the present application, the term "anti-adherent" is intended to mean a material or a biocompatible coating that is smooth and non-porous and does not provide space for cell recolonization. The present invention will become more clearly apparent from the following description and the accompanying drawings, in which: FIG. 1 is a sectional view of an abdominal medial hernia or incision; FIG. 2 is a simplified view of the hernia of FIG. Once the surgeon has made an abdominal incision, FIG. 3 is a top view of an embodiment of a mesh for a prosthesis according to the invention. FIGS. 4A and 4B are perspective views, respectively FIG. 5 is a cross-sectional view of a prosthesis according to the invention comprising a ring of FIGS. 4A and 4B, FIG. 5 is a sectional view of a prosthesis according to the invention. Fig. 7 is a perspective view of the prosthesis of Fig. 5; Fig. 7 is a sectional view of another embodiment of the prosthesis according to the invention; Fig. 8 is a perspective view of another embodiment of the prosthesis according to the invention, Figure 9 is a sectional view of the prosthesis of Figure 7, covered with an anti-adherent coating and placed on the implantation site. FIG. 1 shows a hernia defect 100 of the abdominal wall 101 which is characterized by a break in continuity of the fascia 102 surrounding the right muscles 103 and a peritoneal passage 104 forming a sac, the hernia sac 105, which contains either of the fat (epiplon) is a part of the viscera 106, and which then presses on the fatty tissue 107 and is flush with the skin 108. A treatment of a hernia defect 100 consists of replacing and maintaining the viscera 106 in the abdominal cavity 109 FIG. 2 shows the hernia defect 100 of FIG. 1 once the surgeon has incised the skin 108, the abdominal wall 101 and the peritoneum 104 in order to reduce the hernia sac 105. In FIG. viscera are not shown: they have been pushed towards the abdominal cavity 109. The surgeon must now introduce into the abdominal cavity 109, via the incision 110 which he has practiced, a prosthesis intended to strengthen the abdominal wall, before closing the incision 110 by sutures, for example. In the case of an umbilical hernia, the size of the incision 110 is particularly small, for example of the order of 1 to 3 cm in diameter. In Figure 3 is shown a lattice 1 of circular shape, used with the ring of Figures 4A and 4B to make a prosthesis according to the invention. Mesh 1 is made of an arrangement of biocompatible yarns, such as knit, fabric, nonwoven. It can be bioabsorbable, permanent or partially bioabsorbable. Generally, the mesh is perforated and contains pores for better tissue integration. This mesh 1 is generally sufficiently flexible to be folded on itself at the time of introduction into the abdominal cavity 109 via the incision 110. However, in general, the mesh is a textile having no elasticity allowing it to to recover of itself a configuration spread when it was folded on itself. The mesh 1 may be made of a layer of textile or of several layers. The textile may be a two-dimensional or three-dimensional knit. Such lattices are well known to those skilled in the art and are not described in more detail here. The lattice may be provided in the form of a strip which is cut to the dimensions of the defect to be treated. In the example shown, the lattice 1 has a circular shape, adapted to the shape of the incision 110 of the hernia defect 100, and delimited by a peripheral outer edge la. In other embodiments, the shape of the lattice could be oval. Alternatively, the lattice may have a rectangular or square shape: in such a case, the ring of the prosthesis according to the invention results from a cone section or pyramidal dome.

With reference to FIGS. 4A and 4B is shown a ring 201 of a prosthesis 200 (cf FIG. 6) according to the invention: the ring 201 has an inner face 201 a and an outer face 201 b. In the example shown, the ring 201 results from a section of dome of revolution. With reference to FIG. 5, the ring 201 has a height H: this height H is preferably from 1 to 7 mm, more preferably from 1 to 5 mm. Finally, the ring 201 comprises a base 201c here having the shape of a circle. In other embodiments not shown, the dome from which the ring originated could be built on a square or polygonal plane: the base of the ring would then be a square or a polygon. The ring 201 is made of a semi-rigid and flexible material. By "semi-rigid and flexible" is meant according to the present application that the ring, although deformable under the action of particular constraints, such as the application of a centripetal pressure to substantially fold on itself adopts and maintains at rest, i.e. without stress, a determined shape substantially having a conical surface section shape. In particular, the ring of the prosthesis according to the invention, because of its shape and the nature of the material of which it is formed, has an elasticity which enables it to recover its determined shape of conical surface section after loosening of a pressure to deform it temporarily. In this rest position of the ring 201, the mesh 1 is in a substantially flat and spread configuration. The materials that may be suitable for producing the ring of the prosthesis according to the invention may be chosen from any biocompatible material having a certain rigidity and elasticity to meet the expectations described above. The ring 201 can thus be made of any biocompatible material, bioresorbable or not. In a preferred embodiment, it is made of bioabsorbable material. In the present application, the term "bioabsorbable" is understood to mean the characteristic that a material is absorbed by the biological tissues and disappears in vivo after a given period, which may vary for example from one day to several months, depending on the chemical nature of the material. Thus, mention may be made, as bioabsorbable materials suitable for the manufacture of the ring of the prosthesis according to the present invention, polylactic acid (PLA), polycaprolactones (PCL), polydioxanones (PDO), trimethylene carbonates (TMC) polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA), oxidized cellulose, polyglycolic acid (PGA), copolymers of these materials and mixtures thereof. As bioresorbable material suitable for the manufacture of the ring of the prosthesis according to the invention, mention may be made of the polyester (glycolide, dioxanone, trimethylene carbonate) commercially available from Covidien under the trade name "BIOSYN®" or polyester (glycolide, caprolactone, trimethylene carbonate, lactide) commercially available from Covidien under the trade name "CAPROSYN®". Non-bioabsorbable materials suitable for the manufacture of the ring of the prosthesis of the present invention include, for example, polypropylenes, polyesters such as polyethylene terephthalates, polyamides, silicones, polyetheretherketone (PEEK), polyaryletheretherketone (PAEK). and their mixtures. The ring of the prosthesis according to the invention may for example be made in one piece, by injection molding one or more thermoplastic biocompatible materials. Alternatively, the ring can be made by gluing several films of materials, resorbable or not, hot compression of several layers of textiles. Referring to Figures 5 and 6, there is shown a prosthesis 200 once the mesh 1 of Figure 3 has been attached to the ring of Figures 4A and 4B. As it appears from FIG. 5, in the example shown, the mesh 1 is fixed to the ring 201 over the entire height of the latter: in other words, part of the mesh 1 matches the surface of the inner face of the ring 201. In another embodiment, shown in FIG. 8, only the base 201c of the ring 201 is fixed to the outer peripheral edge 1a of the lattice 1. In the two embodiments shown in FIGS. 8, the lattice is fixed to the ring 201 so that it is held in a flat configuration and spread in the plane formed by the base 201c of the ring 201. In another embodiment, shown in FIG. 1 is fixed on the entire height of the ring 201, but on the outer face of the ring 201. Thus, a portion of the mesh 1 matches the surface of the outer face of the ring 201. Here too, the lattice is attached to the ring 201 so that it is held in a confi flat and spreading guration. As shown in FIG. 7, the central part of the mesh 1 may be provided with one or more centering threads 203 intended to help the surgeon to position the prosthesis with respect to the hernia defect and then to fix it to the abdominal wall. Preferably, the central portion of the mesh 1 is provided with at least two centering wires, more preferably at least three or four centering wires. Preferably, the centering threads are symmetrically distributed in the central part of the lattice at a distance from the central point of the lattice, in order to equilibrate each other: the presence of several centering threads thus distributed allows the surgeon to balance the tension between the various centering wires when positioning the prosthesis and to better center the latter vis-à-vis the defect to fill.

The prosthesis may be provided to the surgeon already provided with this or these centering wire (s). Alternatively, the surgeon can himself install this centering wire, and possibly other son, just before proceeding to the surgical operation. The mesh 1, in particular its peripheral outer edge 1a, can be fastened to the base 201c or to the entire inner or outer surface of the ring 201 by ultrasonic welding. The ring 201 can be fixed to the mesh 1 by any method ensuring a reliable combination of the mesh 1 and the ring 201. For example, the ring 201 can be glued, welded, for example by ultrasonic welding, or sewn to the mesh 1 As shown in FIG. 9, the prosthesis 200 may be covered with a non-stick coating 204 on its outer face 202, and in particular on the outer face of the mesh 1, in order to avoid, in particular, the formation of adhesions. severe fibrotic post-surgical unwanted; once the prosthesis 200 has been implanted, the external face 202 of the prosthesis 200, consisting essentially of the outer face of the mesh 1, is situated opposite the abdominal cavity 109. The non-stick material or coating is chosen from among the bioabsorbable materials , non-bioabsorbable materials and mixtures thereof. The non-bioabsorbable release materials may be selected from polytetrafluoroethylene, polyethylene glycols, polysiloxanes, polyurethanes, stainless steels, precious-metal derivatives and mixtures thereof. Preferably, said non-adherent material or coating is bioresorbable: the bioabsorbable materials that are suitable for said release coating may be chosen from collagens, oxidized celluloses, polyacrylates, trimethylene carbonates, caprolactones, dioxanones, glycolic acid, lactic acid, glycolides, lactides, polysaccharides, for example chitosans, polyglucuronic acids, hyaluronic acids, dextrans and mixtures thereof.

The non-stick coating makes it possible to protect, at least during the initial healing phase, the mesh 1 of the prosthesis 200, namely that the mesh 1 is not exposed to inflammatory cells, such as granulocytes, monocytes, macrophages or the multinucleated giant cells generally activated by the surgical gesture. Indeed, at least during the initial phase of healing, the duration of which may vary from approximately 5 to 10 days, only the release coating is accessible by the various factors such as proteins, enzymes, cytokines or tumor cells. the inflammatory line, at the level of the first part of textile. In the case where the non-stick coating consists of 20 non-resorbable materials, it thus protects the mesh 1 before and after implantation, over the entire duration of implantation of the prosthesis 200. Moreover, thanks to the non-stick coating, surrounding fragile tissues such as hollow viscera, for example, are protected, particularly from the formation of undesired severe post-surgical fibrous adhesions. In the case where the non-stick material comprises a bioabsorbable material, it is preferable to choose a bioabsorbable material which does not resorb for several days so that the release coating can perform its function of protecting the intestine and organs during the 30 days following the operation, and until the cellular rehabilitation of the prosthesis in turn protects the fragile organs. Due to its elasticity, the ring 201 can adopt a configuration in which it is substantially folded back on itself, under the effect of a centripetal radial stress. Thus, when the surgeon 35 wishes to implant the prosthesis 200, he exerts a pressure on the outer face 201 b of the ring 201 in the centripetal radial direction: the entire prosthesis 200 then folds back on itself to occupy a volume reduced and the introduction of the prosthesis in the hernia hole 110 (see Figure 2) by the surgeon is thus facilitated. The mesh 1 and the non-stick coating 204 (see Figure 9) are sufficiently flexible to follow the successive deformations of the ring 201 of the prosthesis 200, when the latter is introduced to the implantation site. After having made the incision 110 described in FIG. 2, the surgeon exerts on the prosthesis 200, covered with a non-stick coating 204 on the outer face of the mesh 1 a centripetal radial stress such as with his fingers in order to fold the prosthesis 200 on itself and introduce it into the abdominal cavity 109. Once the prosthesis 200 is in the abdominal cavity 109, the surgeon releases the centripetal radial pressure it exerted on the latter.

Due to its elasticity, the ring 201, and therefore the prosthesis 200, resumes its rest configuration, as described in FIG. 7. Thus, the prosthesis 200 automatically deploys in the abdominal cavity 109, with the external face 202 of the prosthesis 200, covered with the release coating 204, facing the abdominal cavity 109, and the mesh 1 is perfectly stretched and spread.

In a next step, the surgeon uses (or) centering wire (s) 203 both to center the prosthesis 200 relative to the incision 110 and both to press the prosthesis 200 against the abdominal wall. (101, 104). To do this, it draws significantly on the centering wire 203 as shown in Figure 9. In this step, the surgeon can pull on the centering wire 203 without fear of risking reversion of the prosthesis 200. Indeed thanks to the particular shape of the ring 201 of the prosthesis 200, and thanks to the fact that the ring 201 is at least fixed to the outer peripheral edge 1a of the lattice 1, the latter, and therefore the prosthesis 200, can not be reversed (that is to say reintroduce in the orifice 110). Thus, the more the surgeon pulls on the centering wire 203 and puts it under tension, the more the ring 201 plates the mesh 1 to the abdominal wall (101, 104), the mesh 1 matching the shape of the latter. In FIG. 9, the deformations of the mesh 1 created by the traction exerted on the centering wire 203 are exaggeratedly represented in order to facilitate understanding: in reality, the mesh 1 follows the possible deformations of the abdominal wall and marries the shape of the latter spreading. Thus, the mesh 1 is perfectly spread out and there is no risk that viscera interpose between the mesh 1 and the abdominal wall (101, 104). It then remains for the surgeon to suture the centering wire (s) 203 to the abdominal wall (101, 104) by closing the incision 110.

As it appears in FIG. 9, the prosthesis 200 is thus perfectly deployed, spread out and pressed against the abdominal wall (101, 104) without the risk of insertion of viscera between the prosthesis and the abdominal wall (101, 104). In the case where the ring 201 is bioabsorbable, a sufficient resorption time is chosen to allow the mesh 1 to be recolonized before the disappearance of the ring 201. The fixing of the mesh 1 is thus ensured in the long term. The establishment of the prosthesis according to the invention is particularly simple to perform. It is also particularly reliable, any risk of viscera insertion and any risk of reversion of the prosthesis being avoided. A prosthesis according to the invention is particularly suitable for the treatment of umbilical hernias for which the abdominal incision is made and of small size. Indeed, the prosthesis according to the invention is able to adopt a configuration in which it occupies a particularly small volume allowing its easy introduction into the abdominal cavity via a small incision, and without requiring the use of an ancillary specific. Due to its particular structure, the prosthesis according to the invention is automatically deployed in the abdominal cavity without the intervention of an additional tool. Thanks also to its particular structure, the prosthesis according to the invention can be spread out and plated on the abdominal wall effectively, again without requiring the intervention of a specific tool to aid the spreading, and without risk of reversion of the prosthesis. The prosthesis according to the invention therefore makes it possible to perform an effective, simple and rapid treatment of a hernia, in particular an umbilical hernia, while minimizing the risks of relapse. The prosthesis according to the invention is useful in the treatment of hernias, in particular umbilical hernias, for which the hernia defect is small. The geometry of the prosthesis according to the invention, its nature both semi-rigid and flexible, the possibility of fixing this prosthesis centrally vis-à-vis the hernia defect to fill, allow to prevent the reversal (or reversion ) of the prosthesis in the hernia defect, once the prosthesis is implanted.

Claims (7)

REVENDICATIONS1. Prosthesis (200) comprising a mesh (1) flexible delimited by a peripheral outer edge (la), and a reinforcement element of said mesh, characterized in that said reinforcing element comprises at least one ring (201) semi-rigid and flexible in the form of a substantially conical surface section, said ring being fixed at least at the outer peripheral edge of said lattice and maintaining said lattice in a substantially flat and spread configuration. 2. Prosthesis (200) according to claim 1, characterized in that said mesh (1) is fixed to said ring (201) over the entire height of said ring. 3. Prosthesis (200) according to claim 1 or 2, characterized in that the central portion of said mesh (1) is provided with at least one centering wire (203). 15 4. Prosthesis (200) according to any one of claims 1 to 3, characterized in that said ring (201) is made of bioabsorbable material. 5. Prosthesis (200) according to the preceding claim, characterized in that said bioabsorbable material is selected from polylactic acid (PLA), polycaprolactones (PCL), polydioxanones (PDO), trimethylene carbonates (TMC), polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA), oxidized cellulose, polyglycolic acid (PGA), copolymers of these materials and mixtures thereof. 6. Prosthesis (200) according to any one of claims 1 to 3, characterized in that said ring (201) is made of non-bioabsorbable material selected from polypropylenes, polyesters such as polyethylene terephthalates, polyamides, silicones , polyetheretherketone (PEEK), polyaryletheretherketone (PAEK) and mixtures thereof. 30 7. Prosthesis (200) according to the preceding claim, characterized in that it is covered on its outer face (202) by an anti-adhesive coating (204). 35