Prosthesis for hernia repair

Abstract

The present invention relates to a prosthesis (1) for hernia repair comprising a reinforcement layer (2), a first barrier layer (3) of anti-adhesion material covering at least a part of a surface of the reinforcement layer, and a second barrier layer of anti-adhesion material covering a remaining part of the surface of the reinforcement layer, the second barrier layer being formed of one or more flap member(s) (4).

Claims

1. A method of treating a hernia defect in an abdominal wall including: introducing a prosthesis into an abdominal cavity, the prosthesis including, at least one reinforcement layer, including a biocompatible porous material, the at least one reinforcement layer including a first surface configured to face the abdominal wall and a second surface opposite the first surface, the at least one reinforcement layer being delimited by an outer edge, at least one first barrier layer, including a biocompatible anti-adhesion material, the at least one first barrier layer including a first surface and a second surface opposite the first surface of the at least one first barrier layer, the first surface of the at least one first barrier layer covering substantially a central part of a first area of the second surface of the at least one reinforcement layer, the second surface of the at least one first barrier layer configured to face the abdominal cavity, the at least one first barrier layer being delimited by an outer edge, and at least one second barrier layer, the at least one second barrier layer being shaped and dimensioned so as to cover at least a part of a second area of the second surface of the at least one reinforcement layer that is not covered by the at least one first barrier layer, the at least one second barrier layer including one or more flap members, each of the one or more flap members being formed of a piece of sheet of biocompatible anti-adhesion material, and having at least an outer edge attached to the second surface of the at least one reinforcement layer and a free inner edge, positioning the prosthesis with the first surface of the at least one reinforcement layer facing the abdominal wall, lifting the free inner edge of the one or more flap members to access a protected space between the at least one second barrier layer and at least one of the second surface of the at least one first barrier layer or the second surface of the at least one reinforcement layer, and fixating the prosthesis to the abdominal wall with a fixating means positioned within the protected space and covered by the at least one second barrier layer.

2. The method of claim 1, wherein fixating the prosthesis further comprises introducing a fixating tool into the protected space to apply the fixating means into the protected space and the abdominal wall.

3. The method of claim 1, wherein the fixating means is selected from the group consisting of clips, tacks, screws, straps, spirals, staples, and sutures.

4. The method of claim 1, wherein the fixating means is a tack.

5. The method of claim 1, wherein lifting the free inner edge of the one or more flap members includes grasping one or more projecting tabs extending from the free inner edge towards a central part of the at least one first barrier layer, the one or more projecting tabs configured to help a surgeon lift the one or more flap members.

6. The method of claim 1, wherein the introducing the prosthesis includes passing the prosthesis in a folded configuration through a trocar.

7. The method of claim 1, further comprising insufflating the abdominal cavity and reduction of a hernial sac of the hernia defect prior to introducing the prosthesis.

8. The method of claim 1, wherein the one or more flap members includes at least one first flap member having a form of an annular band, an outer edge of the at least one first flap member being substantially attached to the second surface of the at least one reinforcement layer along the outer edge of the at least one reinforcement layer.

9. The method of claim 8, wherein the one or more flap members further includes at least one second flap member, an outer edge of the at least one second flap member being substantially attached to the second surface of the at least one reinforcement layer along a line located between the outer edge of the at least one reinforcement layer and the outer edge of the at least one first barrier layer.

10. The method of claim 9, wherein the at least one second flap member has a form of a second annular band, the at least one first and second flap members being concentrically positioned one with respect to the other, so that the outer edge of the at least one second flap member is substantially attached to the second surface of the at least one reinforcement layer along a line substantially parallel to the outer edge of the at least one reinforcement layer, the line being located between the outer edge of the at least one reinforcement layer and the outer edge of the at least one first barrier layer.

11. The method of claim 9, wherein the one or more flap members further includes at least one third flap member having an outer edge, each of the at least one second and third flap member having a form of a tape portion, the respective outer edges of the at least one second and third flap members being substantially attached to the second surface of the at least one reinforcement layer along line(s) located between the outer edge of the at least one reinforcement layer and the outer edge of the at least one first barrier layer, wherein positioning the prosthesis includes positioning the line(s) in a vicinity of an edge of the hernia defect.

12. The method of claim 8, wherein the outer edge of the at least one first flap member is attached to the second surface of the at least one reinforcement layer so as to define an attaching line which is offset towards a center of the prosthesis from about 0.5 to about 2 cm from the outer edge of the at least one reinforcement layer.

13. The method of claim 1, wherein the outer edge of the one or more flap members is attached to the second surface of the at least one reinforcement layer by attaching means selected from the group including ultrasonic welding, hot compression welding, gluing and combinations thereof.

14. The method of claim 1, wherein a total surface area resulting from the addition of a surface area of each of the one or more flap members is less than 120% of a surface area of the second area of the second surface of the at least one reinforcement layer that is not covered by the at least one first barrier layer.

15. The method of claim 1, wherein the at least one second barrier layer is provided with markings intended to indicate to a surgeon where to locate the fixating means for fixing the prosthesis to the abdominal wall.

16. The method of claim 15, wherein the markings are colored spots located on a surface of the at least one second barrier layer intended to face the abdominal cavity.

17. The method of claim 16, wherein the markings are regularly spaced from one another along a perimeter of the at least one second barrier layer.

18. The method of claim 1, wherein a smallest dimension of a shape of the piece of sheet of anti-adhesion material forming the one or more flap members ranges from about 1 cm to 4 cm.

19. A prosthesis for treating a hernia defect in an abdominal wall comprising: at least one reinforcement layer, including a biocompatible porous material, the at least one reinforcement layer including a first surface configured to face the abdominal wall and a second surface opposite the first surface, the at least one reinforcement layer being delimited by an outer edge, at least one first barrier layer, including a biocompatible anti-adhesion material, the at least one first barrier layer including a first surface and a second surface opposite the first surface of the at least one first barrier layer, the first surface of the at least one first barrier layer covering substantially an area of the second surface of the at least one reinforcement layer, the second surface of the at least one first barrier layer configured to face the abdominal cavity, the at least one first barrier layer being delimited by an outer edge, and a first flap member formed of a piece of a first sheet of first biocompatible anti-adhesion material, the first flap member including a first surface and a second surface opposite the first surface of the first flap member, the first surface of the first flap member including an outer edge attached to the second surface of the at least one first barrier layer and a free inner edge of the first flap member, free of the at least one first barrier layer, and a second flap member formed of a piece of a second sheet of biocompatible anti-adhesion material, the second flap member including a first surface and a second surface opposite the first surface of the second flap member, the first surface of the second flap member including an outer edge attached to the second surface of the first flap member and a free inner edge free of the first flap member.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The present invention will become clearer from the following description and from the attached drawings, in which:

(2) FIG. 1 is an exploded view of a first embodiment of the prosthesis of the invention,

(3) FIG. 2 is a bottom perspective view of the prosthesis of FIG. 1,

(4) FIG. 3 is a cross sectional view of the prosthesis of FIG. 2 taken along plane I-I′,

(5) FIG. 4 is a bottom view of another embodiment of the prosthesis of the invention,

(6) FIG. 5 is a bottom view of another embodiment of the prosthesis of the invention,

(7) FIG. 6 is a bottom view of another embodiment of the prosthesis of the invention,

(8) FIG. 7A is a cross section view of the prosthesis of FIG. 6 taken along plane II-II′,

(9) FIG. 7B is a cross section view of an alternative embodiment of the prosthesis of FIG. 6,

(10) FIG. 8 is a bottom view of another embodiment of the prosthesis of the invention,

(11) FIG. 9 is a sectional view of a median abdominal hernia,

(12) FIG. 10 is a sectional view of the hernia of FIG. 9 once the hernia sac (not shown) has been reduced and the prosthesis of FIG. 1 has been introduced in the abdominal cavity,

(13) FIG. 11 is a cross sectional view showing the tacking of the prosthesis of FIG. 1 to the abdominal wall,

(14) FIG. 12 is a cross sectional view showing the prosthesis of FIG. 1 fixed to the abdominal wall, with the first barrier layer of the prosthesis covering the heads of the tacks.

DETAILED DESCRIPTION OF THE INVENTION

(15) With reference to FIGS. 1-3 is shown a prosthesis 1 in accordance with the present invention intended to be used in the treatment of hernia, in particular ventral hernia, via the laparoscopic route. The prosthesis 1 comprises a reinforcement layer 2, intended to provide strength and mechanical properties to the prosthesis 1, a first barrier layer 3 intended to limit and prevent the formation of adhesions between the reinforcement layer 2 and the organs of the abdominal cavity (see FIGS. 10-12), and a second barrier layer 4 intended to prevent the formation of adhesions between the organs of the abdominal cavity 109 and the fixing means for fixing the prosthesis 1 to the abdominal wall 104.

(16) The reinforcement layer 2 is made of a biocompatible porous material, in particular capable of promoting tissue ingrowth. The reinforcement layer may be under the form of a sponge, for example obtained by lyophilisation of a polymeric composition, a fibrous matrix such as a textile or combinations thereof. The reinforcement layer preferably shows mechanical properties allowing it to perform its function of strengthening and repairing the abdominal wall.

(17) Reinforcement layers are well known in the art. In embodiments, the reinforcement layer may be a textile, such as a bidimensional porous knit or a three-dimensional porous knit.

(18) With reference to FIGS. 1-3, the reinforcement layer 2 has the shape of a rectangle, with rounded corners. In other embodiments, the reinforcement layer may have an oval shape. Such embodiments are suitable, for example, for the treatment of a ventral hernia. In embodiments, the reinforcement layer has the shape of a disc. Such an embodiment is suitable, for example, for the treatment of an umbilical hernia. The reinforcement layer may exhibit any shape as long as said shape is large enough so as to cover efficiently the hernia defect to be treated.

(19) The reinforcement layer 2 has a first surface 2a and a second surface 2b, opposite the first surface. On the example shown, the first surface 2a is intended to face the abdominal wall (see FIGS. 10-12). The reinforcement layer 2 is delimited by an outer edge 2c and has a center C.

(20) The prosthesis 1 further comprises a first barrier layer, under the form of a film 3 on the example shown. The first barrier layer or film 3 is made of a biocompatible anti-adhesion material. The film 3 shows a first surface 3a and a second surface 3b, opposite the first surface 3a. The first barrier layer or film 3 is delimited by an outer edge 3c.

(21) The anti-adhesion material forming the first barrier layer or film 3 allows preventing post surgical adhesions between the viscera organs of the abdominal cavity and the porous material forming the reinforcement layer 2. The first surface of the first barrier layer, such as the film 3, covers at least a central part of the area of the second surface 2b of the reinforcement layer 2. In the example shown on FIGS. 1-3, the first surface of the first barrier layer, such as the film 3, covers the entire area of the second surface 2b of the reinforcement layer 2. As such, the second surface of the first barrier layer, such as the film 3, is intended to face the abdominal cavity and therefore protects the viscera organs of the abdominal cavity from the reinforcement layer 2.

(22) In other embodiments (see FIG. 7B), the first surface of the first barrier layer, such as the film 3, covers only a central part of the area of the second surface 2b of the reinforcement layer 2.

(23) The anti-adhesion material may be chosen from among bioresorbable materials, non-bioresorbable materials and mixtures thereof. The non-bioresorbable anti-adhesion materials can be selected from among polytetrafluoroethylene, polyethylene glycols, polysiloxanes, polyurethanes, and mixtures thereof.

(24) The anti-adhesion material is preferably bioresorbable: the bioresorbable materials suitable for said anti-adhesion material can be selected from among collagens, oxidized celluloses, polyethylene glycol, polyacrylates, trimethylene carbonates, caprolactones, dioxanones, butyric or glycolic acid, lactic acid, glycolides, lactides, polysaccharides, for example chitosans, polyglucuronic acids, hyaluronic acids, dextrans, and mixtures thereof.

(25) For example, the film 3 of FIGS. 1-3 is a film of a copolymer of glycolide, lactide, trimethylene carbonate and e-caprolactone, the preparation of which is described in U.S. Pat. No. 6,235,869. The film may be applied on the reinforcement layer 2 by a lamination process.

(26) In other embodiments, the film 3 may be a non porous collagen film or a bioabsorbable collagen film based on oxidized collagen with polyethylene glycol. Such films based on collagen may be obtained by application on the second surface of the reinforcement layer of a solution based on collagen and by gelification of the solution thereon.

(27) In other embodiments, the first barrier layer is a coating obtained by spraying a solution or a suspension of an anti-adhesion material on the second surface of the reinforcement layer 2.

(28) The prosthesis 1 further comprises a second barrier layer, consisting in a flap member under the form of a first skirt 4 on FIGS. 1-3, made of a biocompatible anti-adhesion material. The first skirt 4 is a piece of sheet of biocompatible anti-adhesion material under the form of an annular band shaped film. The anti-adhesion material forming the second barrier layer or first skirt 4 allows preventing post surgical adhesions between the viscera organs of the abdominal cavity and the fixing means used to fix the prosthesis to the abdominal wall, as will appear from the description below.

(29) The anti-adhesion material forming the second barrier layer, namely the first skirt 4, may be chosen among the same materials as described above for the anti-adhesion material forming the first barrier layer. The anti-adhesion material forming the first skirt 4 may be identical or different than the anti-adhesion material forming the film 3.

(30) For example, the first skirt 4 is made of a film of a copolymer of glycolide, lactide, trimethylene carbonate and e-caprolactone, the preparation of which is described in U.S. Pat. No. 6,235,869.

(31) The first skirt 4 has an outer edge 5a and an inner edge 5b. The annular band forming the first skirt 4 has preferably a width, corresponding to the length measured along a direction aligned on a radius of the reinforcement layer extending from the center C of the reinforcement layer to a point of the outer edge of the reinforcement layer, ranging from about 1 cm to 4 cm, preferably from 2 cm to 3 cm. The first skirt 4 is therefore particularly adapted for covering the proximal ends of the fixing means used for fixing the prosthesis 1 to the abdominal wall.

(32) The first skirt 4 further shows a first surface 4a, intended to face the first barrier layer or film 3, and a second surface 4b intended to face the abdominal cavity (see FIGS. 10-12). In embodiments (not shown), the first skirt 4 is provided on its surface regarding the film 3 with a tacky layer of biocompatible materials capable of sticking to film 3. The biocompatible materials suitable for forming the tacky layer may be selected from collagen-based, polylactone-based, polylactic, polyethylene glycol, polysaccharides and/or polyvinyl alcohol based surgical adhesives, fibrin glues, and combinations thereof.

(33) In the example shown, with reference to FIG. 3, the outer edge 5a of the first skirt 4 is attached to the second surface of the reinforcement layer 2 along the outer edge 2c of the reinforcement layer 2 by the intermediate of the film 3. In other words, the outer edge 5a of the first skirt 4 is therefore attached along the outer edge 3c of the film 3. The inner edge 5b of the first skirt 4 is left free.

(34) Preferably, the outer edge 5a of the first skirt 4 is attached along the outer edge 3c of the film 3 in a continuous way. For example, the outer edge 5a of the first skirt 4 is attached to the film 3 so as to define an attaching line 6 which is offset towards a center of the prosthesis from about 0.5 to about 2 cm, preferably about 1 cm, from said outer edge. As will appear from the description of FIGS. 10-12 below, such embodiments guaranty that the fixing means, such as clips, tacks, screws, spirals, straps, staples, suture or transfacial sutures, will not move too close to the outer edge of the prosthesis 1.

(35) The first barrier layer, such as the film 3, and the second barrier layer, such as the first skirt 4, may be attached one to the other by attaching means selected from the group comprising ultrasonic welding, hot compression welding, gluing and combinations thereof.

(36) For example, in case the anti-adhesion material forming the first and second barrier layers is selected from polylactic acid, polyglycolic acid, trimethylene carbonates, polyethylene glycol, polycaprolactone, and combinations thereof, the first barrier layer and the second barrier layer may be attached one to the other via ultrasonic welding by applying pressure and piezo energy to ensure local fusion of the two barriers.

(37) Alternatively, in case the anti-adhesion material forming the first and second barrier layers is a collagen or derivatives thereof, the first barrier layer and the second barrier layer may be attached one to the other via a gluing agent, for example a gluing agent capable of locally solubilising both barriers in order to fusion them. The gluing agent may be a collagen water solution, with or without a crosslinking agent. For example, in contact with such a collagen water solution, the first and second barriers' surfaces will tend to melt, and by a drying process the first and second barriers will be unified.

(38) For example, in the present example, the film 3 and the first skirt 4 being each made of a film of a copolymer of glycolide, lactide, trimethylene carbonate and e-caprolactone, the first skirt 4 is attached to the film 3 by ultrasonic welding. The first skirt 4 is therefore securely attached to the film 3.

(39) As shown on FIG. 3 and as will appear from the description below, the shape of the flap member forming the second barrier layer, namely the first skirt 4, and the way it is attached to the first barrier layer, e.g. the film 3, allow creating an adequate protected space 11 located between the film 3 and the first skirt 4 for lodging the fixing means, such as tacks, intended to fix the prosthesis to the abdominal wall (see FIG. 12).

(40) With reference to FIGS. 4-8 are shown other embodiments of the prosthesis 1 of the invention. In these Figures, references designating the same elements as in the prosthesis 1 of FIGS. 1-3 have been maintained.

(41) With reference to FIG. 4 is shown an alternative embodiment of a prosthesis 1 of the invention, provided with markings 7 intended to indicate to the surgeon where to locate one or more fixing means for fixing the prosthesis 1 to the abdominal wall. On the example shown, the markings 7 are regularly spaced from one another along a perimeter of the second barrier layer or first skirt 4. With reference to FIG. 4, the markings 7 are under the form of colored spots located on the surface 4b of the first skirt 4 which is intended to face the abdominal cavity: the fixing means are optimally positioned underneath the first skirt 4, at points corresponding to the localization of the colored spots. In other embodiments not shown, the markings may have the shape of crosses, triangles, etc.

(42) In embodiments, the markings are distant 1.5 cm from one another. Such embodiments allow the surgeon to easily position the fixing means, such as tacks, at intervals of 1.5 cm. Such a fixation technique is usually associated with a low recurrence rate of the hernia.

(43) Alternatively, markings, such as a dotted line, may be provided on the reinforcement layer 2 itself.

(44) In embodiments, the second barrier layer or first skirt 4 may be provided with identification means for distinguishing said first skirt 4 from said first barrier layer or film 3. For example, the first skirt 4 may show a color different than that of the film 3. In other embodiments, the first skirt 4 may be provided with specific designs drawn on flap member(s), such as geometric figures, etc.

(45) With reference to FIG. 5 is shown an alternative embodiment of a prosthesis 1 of the invention, wherein the inner edge 5b of the second barrier layer or first skirt 4, is provided with a projecting tab 8. The projecting tab 8 is intended to help the surgeon lift the first skirt 4 from the film 3. In particular, the surgeon may grasp the projecting tab 8 with a grasper or other instrument so as to pull on it and lift the inner edge 5b of the first skirt 4, thereby opening a larger access to the protected space located between the first skirt 4 and the film 3.

(46) In embodiments not shown, the first skirt 4 could be provided with one or more tabs, positioned anywhere along the length of its inner edge, for example positioned along the mid-line of a side of the inner edge where a minimal amount of force will create a greater separation between the first skirt 4 and the reinforcement layer 2 along that side of the first skirt 4.

(47) With reference to FIGS. 6 and 7A, is shown an alternative embodiment of a prosthesis 1 of the invention, wherein the second barrier layer comprises a first flap member, under the form of a first skirt 4 like in FIGS. 1-3, and a second flap member, under the form of a second skirt 9. In the example shown, the second barrier layer consists in said first and second skirts (4, 9). The second skirt 9 is a piece of sheet of biocompatible anti-adhesion material under the form of an annular band shaped film. The anti-adhesion material used for the second skirt 9 may be the same or different than the anti-adhesion material used for the first skirt 4.

(48) For example, the second skirt 9 is made of a film of a copolymer of glycolide, lactide, trimethylene carbonate and e-caprolactone, the preparation of which is described in U.S. Pat. No. 6,235,869.

(49) In the Example shown on FIGS. 6 and 7A, the second skirt 9 is located between the first barrier layer or film 3 and the first flap member or first skirt 4. The second skirt 9 is delimited by an outer edge 10a and an inner edge 10b. The outer edge 10a of the second skirt 9 is substantially attached along the outer edge 2c of the reinforcement layer 2 by the intermediate of the outer edge 3c of the film 3 forming the first barrier layer.

(50) Moreover, as shown on FIGS. 6 and 7A, the inner edge 10b of the second skirt 9 is free and extends beyond the inner edge 5b of the annular band film 4 in the direction of the center C (see FIG. 1) of the reinforcement layer 2.

(51) The second skirt 9 may be attached to the film 3 and to the first skirt 4 by the same methods as described above for attaching the film 3 to the first skirt 4. For example, in the present example, the film 3, the second skirt 9 and the first skirt 4 being each made of a film of a copolymer of glycolide, lactide, trimethylene carbonate and e-caprolactone, the first skirt 4, second skirt 9 and film 3 may be attached altogether by ultrasonic welding. The first skirt 4, second skirt and film 3 are therefore securely attached together.

(52) As shown on FIG. 7A, the respective shapes and attachment structures of the first skirt 4 and of the second skirt 9 allow creating two different protected spaces (12, 13) for lodging fixing means, such as tacks, intended to fix the prosthesis to the abdominal wall. With reference to FIG. 7A, a first protected space 12 is created between the film 3 and the second skirt 9, and a second protected space 13 is created between the second skirt 9 and the first skirt 4.

(53) With reference to FIG. 7B, is shown an alternative embodiment of a prosthesis 1 of FIG. 7A in which the first barrier layer under the form of the film 3 covers only a central part of the area of the second surface of the reinforcement layer 2 and the outer edge 10a of the second skirt 9 is substantially attached to the second surface of the reinforcement layer 2 along a line located between the outer edge 2c of the reinforcement layer 2 and the outer edge 3c of the first barrier layer or film 3. In particular, the first skirt 4 and the second skirt 9 are concentrically positioned one with respect to the other, so that the outer edge 10a of the second skirt 9 is substantially attached to the second surface of the reinforcement layer 2 along a line substantially parallel to the outer edge 2c of the reinforcement layer 2, the line being located between the outer edge 2c of the reinforcement layer 2 and the outer edge 3c of the first barrier layer formed by the film 3.

(54) As appears from FIG. 7B, the second barrier layer, which consists in the first skirt 4 and the second skirt 9, is shaped and dimensioned so as to cover at least the part of the area of the second surface of the reinforcement layer 2 that is not covered by the first barrier layer or film 3. In particular, in the example shown, the inner edge 5b of the first skirt 4 forming the first flap member overlaps the outer edge 10a of the second skirt 9 forming the second flap member, and the inner edge 10b of the second skirt 9 overlaps the outer edge 3c of the film 3 forming the first barrier layer. As a result, the entire area of the second surface of the reinforcement layer 2 is safely covered by anti-adhesion material, said anti-adhesion material being provided either by the film 3 forming the first barrier layer or by the first skirt 4 or the second skirt 9 forming the first and second flap members of the second barrier layer. Such an embodiment allows reducing the amount of anti-adhesion material implanted into the body of the patient, while ensuring a safe covering of the entire area of the second surface of the reinforcement layer 2 by an anti-adhesion material. Moreover, when the anti-adhesion materials forming the first barrier layer and the second barrier layer are biodegradable, such embodiments allow an even degradation profile for the first and second barrier layers across the entire second surface of the reinforcement layer 2.

(55) Such embodiments of the prosthesis 1 of the invention as shown on FIGS. 7A and 7B are particularly useful for allowing the surgeon to complete a reinforced fixation. Indeed, when the hernia defect to be repaired is large, it may be useful to fix the prosthesis 1 to the abdominal wall using two sets of fixing means. For example, a first set of tacks may be positioned according to a circle configuration in the vicinity of the edges of the defect. In the present example, this first circle of tacks could be positioned in the first protected space 12 of prosthesis 1 of FIGS. 6-7B, with for example a regular space between two adjacent tacks, such as 1 cm. Then, a second set of tacks may be positioned according to a second circle, of larger diameter, in the vicinity of the peripheral outer edge of the prosthesis, preferably at a distance of about 1 cm set back from this peripheral outer edge, as explained above. In the present example, this second circle of tacks could be positioned in the second protected space 13 of prosthesis 1 of FIGS. 6-7B, with for example a regular space between two adjacent tacks, such as 1 cm. Once the prosthesis 1 is fixed to the abdominal wall, the second skirt 9 covers the heads of the tacks positioned on the first circle, and the first skirt 4 covers the tacks of the second circle. The viscera organs of the abdominal cavity are therefore well protected from the fixing means, such as tacks, of the prosthesis, and potential surgical adhesion between the tacks and the viscera organs are avoided.

(56) With reference to FIG. 8 is shown an alternative embodiment of a prosthesis 1 of the invention, in which the second barrier layer comprises a first flap member, under the form of a first skirt 4 like in FIGS. 1-3, and a second and third flap members, the second and third flap members each being under the form of a longitudinal tape portion 14 intended to be positioned in regards of edges of the hernia defect once the prosthesis 1 is implanted. In the example shown, the second barrier layer consists in the first skirt 4 and the two longitudinal tape portions 14. The two longitudinal tape portions 14 extend from a small side of the prosthesis 1 to the other. The outer edge (not visible) of each longitudinal tape portion 14 is attached to the reinforcement layer by the intermediate of the film 3, the inner edge 14b of each longitudinal tape 14 being left free.

(57) Such embodiment allows creating two longitudinal protected spaces 15, located between the film 3 and the tape portions 14, for lodging fixing means, such as tacks, in the vicinity of the defect edges.

(58) The method of treating a hernia defect with the prosthesis 1 of FIGS. 1-3 will now be described in reference to FIGS. 9-12. In FIGS. 11 and 12, the prosthesis of FIGS. 1-3 is drawn in a simplified manner so as to clarify the Figures.

(59) FIG. 9 shows a hernia defect 100 of the abdominal wall 101, characterized by a break in continuity of the fascia 102 surrounding the rectus muscles 103 and by a passage through the peritoneum 104 forming a sac, the hernial sac 105, which contains either fat (greater momentum) or part of the viscera 106, and which thus exerts pressure on the fatty tissues 107 and lies flush with the skin 108. Treatment of a hernia defect 100 involves repositioning and maintaining the viscera 106 in the abdominal cavity 109.

(60) FIG. 10 shows the hernia defect from FIG. 9 after insufflation of the abdominal cavity 109 and reduction of the hernial sac 105 by the surgeon by laparoscopic surgery. The viscera organs are not shown in FIG. 10: they have been pushed back towards the abdominal cavity 109. Once the hernial sac 105 is reduced, the prosthesis 1 of FIGS. 1-3 is introduced in the abdominal cavity 109 by means of a trocar (not shown) and positioned with the first surface 2a of the reinforcement layer 2 facing the abdominal wall 101 and peritoneum 104, as shown on FIG. 10.

(61) The surgeon then moves the prosthesis 1 closer to the peritoneum 104/abdominal wall 101 so that the first surface 2a of the prosthesis 1 bears on the peritoneum 104/abdominal wall 101; the surgeon grasps the inner perimeter 5b of the first skirt 4 with a laparoscopic tool so as to lift the first skirt 4 and gain access to the protected space 11. A tacker 17 is then introduced in the abdominal cavity 109 by means of a trocar (not shown). The distal end of the tacker 17 is introduced in the protected space 11 and a tack 16 is fired in the direction of the peritoneum 104/abdominal wall 101, as shown on FIG. 11.

(62) In embodiments where the attaching line 6 of the prosthesis 1 is continuous and offset towards the center of the prosthesis 1 from the outer edge 3c of the first barrier layer of film 3, as shown on FIGS. 3, 11 and 12, the surgeon may feel particularly comfortable with the gesture of introducing the distal end of the tacker 17 into the protected space 11 and of firing a tack 16, as he is ensured that the tacks 16 will not move too close to the outer edge of the prosthesis 1. In addition, because of the strong and efficient attaching between the second barrier layer or first skirt 4 and the reinforcement layer 2 or first barrier layer or film 3, the surgeon knows that he can firmly push on the tacker 17 in the distal direction and therefore in the direction of the abdominal wall without fearing that the second barrier layer separates from the first barrier layer and/or from the reinforcement layer. The integrity of the assembly of the reinforcement layer/first barrier layer and second barrier layer is not compromised by the movement of the tacker 17 in the protected space 11.

(63) The same operation is repeated for each tack 16, as many times as deemed necessary by the surgeon in order to obtain an efficient fixation of the prosthesis 1 to the peritoneum 104/abdominal wall 101.

(64) With reference to FIG. 12, two tacks 16 are shown after they have been fired in the protected space 11. As shown on this Figure, the tacks 16 fix both the reinforcement layer 2 and the first barrier layer of film 3 to the peritoneum 104/abdominal wall 101 with their proximal end, namely their head 16a, protruding in the protected space 11. The first skirt 4 covers the heads 16a of the tacks 16 so that no part of the tacks 16 is in contact with the viscera organs (not shown) present in the abdominal cavity 109.

(65) As a result, the risk of recurrence provoked by the formation of post-surgical adhesions between the fixing means, such as tacks 16, and the viscera organs of the abdominal cavity 109 is dramatically decreased with the prosthesis 1 of the invention.

(66) In embodiments, the first skirt 4 is provided on its surface regarding the film 3 with a tacky layer of biocompatible materials, and the surgeon may cover the head 16a of each tack 16 and then stick the first skirt 4 to the film 3 for a reinforced protection and reliable separation of the tack's head from the surrounding biological issues of the abdominal cavity.

(67) The prosthesis of the invention therefore allows completing intraperitoneal repair with fewer risks of recurrence or of postoperative complications.