IMPLANTABLE BREAST PROSTHESIS AND MANUFACTURING PROCEDURES

Description

technical field

[0001] This disclosure relates to a breast prosthesis and its manufacturing method. Previous technique

[0002] It is known that breast implants can be used to perform breast reconstruction following a mastectomy (removal of the breast) as part of cancer treatment, or after necrosis resulting from infection or trauma. Breast implants can also be used for cosmetic purposes to modify the shape or volume of the breasts.

[0003] There are different types of breast implants that differ in particular by: their shape, which can be for example anatomical, round, expansion prosthesis type or asymmetrical prosthesis type (left, right), their outer shell, which can be for example polyurethane or silicone, by the texturization of their outer shell, which can be for example smooth, microtextured or macrotextured, by the filling product of the outer shell, which can be for example silicone gel, physiological saline or hydrogel.

[0004] In particular, US document 2011 / 270391 A1 discloses an implantable breast prosthesis comprising a flexible internal skeleton delimiting a filling chamber and a flexible outer shell delimiting a second filling chamber filled with a second fluid.

[0005] Besides the risks associated with capsular contracture, rippling, rippling, or rotation, as well as inflammation or infection, breast implants primarily present a risk of rupture or deflation leading to leakage of the filling material. When silicone gel is involved, this leakage poses a significant danger to the patient, given the potential for local and systemic inflammation, lymph node involvement, and the formation of siliconoma.

[0006] Therefore, there is a need for a breast prosthesis that reduces the risks for the patient.

[0007] Patient comfort and breast restoration that closely matches the patient's expectations, particularly in terms of aesthetics and feel, are also essential specifications. Summary

[0008] This disclosure addresses that need.

[0009] An implantable breast prosthesis is proposed according to claim 1 comprising: ■ a flexible inner skeleton delimiting a first filling chamber filled with a first fluid, this inner skeleton comprising: ◆ an inner base having opposing internal and external surfaces, ◆ an inner cap having internal and external surfaces and attached to the inner base in such a way that the internal surfaces of the inner base and the inner cap are opposite each other, ◆ a bracing structure disposed between the internal surfaces of the inner base and the inner cap and configured to space the inner cap from the inner base, in such a way that the external surface of the inner cap has a convexity, ■ a flexible outer envelope delimiting a second filling chamber filled with a second fluid, this second filling chamber surrounding the inner skeleton.

[0010] Thus, the breast prosthesis according to the invention features a bracing structure that guarantees the maintenance of shape, support, and volume regardless of the first and second fluids with which the first and second filling chambers are filled. According to specific provisions, the bracing structure eliminates the need for silicone gel, which is the source of known major problems.

[0011] One of the advantages of this prosthesis also lies in its lightness.

[0012] Another positive point to the credit of this prosthesis is the homogeneous return of force on the surface (2nd chamber), during palpation.

[0013] According to specific provisions, the breast prosthesis according to the invention reduces surgical trauma associated with its placement in a retromuscular position. In particular, the breast prosthesis allows for placement in a prepectoral position with a natural result, thus avoiding partial section or detachment of the pectoral muscle.

[0014] The two-part design of the breast prosthesis, namely an internal skeleton and an outer shell, also allows, under specific conditions, for: to secure the texture of the outer shell which is currently implicated in the pathophysiology of anaplastic lymphomas and chronic inflammatory reactions, to secure the placement technique, eliminating any risk of rupture (implant trauma) during implantation, to secure the position of the breast prosthesis to avoid secondary displacements and rotations and subsequent surgical interventions to correct them; the breast prosthesis can indeed have one or more fixing elements securing its position, replacing the periprosthetic inflammation fixations of polyurethane breast prostheses.

[0015] Advantageously: the inner base has a contour around a base axis (A); and the bracing structure includes at least one flexible bracing wall having first and second opposing edges attached, respectively, to the internal surfaces of the inner base and the inner cap.

[0016] In a first embodiment shown on the figures 1 to 3 , the bracing structure is a honeycomb structure (cells with a hexagonal or circular cross-section, for example).

[0017] In a second embodiment shown on the figures 4 to 6 , the first edge and the second edge are aligned along the base axis (A) and the first edge, preferably substantially perpendicular to the base axis (A).

[0018] In a 3rd embodiment not shown in the figures, the wall(s) of the bracing structure has (have) an annular shape with axis (A).

[0019] For some of the walls of the honeycomb structure of the first embodiment and for at least part of the walls, preferably for all the walls, in the 2nd embodiment, the second edge may be aligned with the first edge along the base axis (A).

[0020] In these 3 embodiments, among others, the bracing structure includes an arrangement of bracing walls, configured to define a plurality of compartments in the first filling chamber.

[0021] In some of these embodiments, in particular in the 1st and 2nd embodiments, the compartments respectively have compartment axes (B) parallel to the base axis (A).

[0022] According to one embodiment, the bracing walls of the structure of the same name may have communication openings between the compartments of the first filling chamber. This allows some circulation of the first filling fluid in this first chamber, between all or part of the compartments.

[0023] According to a notable feature of the invention, the bracing structure has a vertex centered on the base axis.

[0024] According to advantageous provisions of the invention, The outer shell of the prosthesis has an inner surface oriented towards the second filling chamber and an outer surface opposite to the inner surface; the inner skeleton has a peripheral skirt attached to the inner surface of the outer shell, such that the second filling chamber has: ➢ a first compartment between the inner surface of the outer shell, the outer surface of the inner cap and the peripheral skirt, ➢ and a second compartment between the inner surface of the outer shell, the outer surface of the inner base and the peripheral skirt.

[0025] According to a preferred feature of the invention, the first and second compartments of the second chamber are in fluid communication, preferably, through holes made through the peripheral skirt, these holes being more preferably equidistant.

[0026] This feature provides a buffer zone for vibrations, which greatly contributes to the comfort of the prosthesis.

[0027] Preferably, the outer casing of the prosthesis comprises: ➢ an outer base having an internal surface opposite the external surface of the inner base, ➢ and an outer cap having internal and external surfaces; the outer base and outer cap preferably being configured so that the inner and outer bases are parallel to each other.

[0028] The outer base, the peripheral skirt and the inner base thus delimit the 2nd compartment of the 2nd filling chamber.

[0029] According to one possibility, the outer base can be a different part from the outer cap and thus be attached and secured to the outer cap and the peripheral skirt, after filling the 2 compartments of the 2nd filling chamber with the 2nd filling fluid.

[0030] The internal skeleton and the external envelope of the prosthesis are preferably made of a natural or synthetic elastomer material, with a Shore A hardness, preferably between 10 and 80, more preferably between 15 and 50, and better still between 25 and 35.

[0031] This elastomeric material is advantageously chosen from the group comprising – ideally consisting of – the following materials: * silicones, in particular " silicones Liquid Silicon Rubber "(LSR) or silicones" Heat Cured Rubber Or High Consistency Rubber"(HCR); in particular silicones comprising polydimethylsiloxanes (PDMS); * plastomers, in particular polydimethylsiloxane (PDMS) and polymethyl methacrylate (PMMA) block copolymers; * copolymers comprising PLA (PLA: polylactic acid), in particular PLA-b-PEG (PEG: polyethylene glycol); * and mixtures of these materials.

[0032] The first and second filling fluids may be different from each other, the first fluid being gaseous at a temperature greater than or equal to 30°C and at atmospheric pressure, the second fluid being liquid at a temperature greater than or equal to 30°C and at atmospheric pressure.

[0033] The first fluid may include air, preferably at a pressure equal to atmospheric pressure.

[0034] The second fluid may comprise a solution with a viscosity between 100 and 500 Pa.s, preferably between 200 and 300 Pa.s. This viscosity is measured according to the method described in "2.2.10. VISCOSITY - ROTATING VISCOMETER METHOD on pages 28 & 29 of " EUROPEAN PHARMACOPEIA 8.0 "by using a" CONCENTRIC CYLINDER VISCOMETER ABSOLUTE VISCOMETER " , and by implementing a " Viscometer-type duvet "(non-Newtonian fluid) as shown in Figures 2.2.10.-1 and 2.2.10.-2, at an average shear rate of 1s -1< , varying between 0.1s -1< and 10s -1< , at ambient temperature and atmospheric pressure.

[0035] The second fluid may comprise a hyaluronic acid solution, preferably at a concentration between 1% by mass and 5% by mass, and, more preferably still, between 2% by mass and 4% by mass.

[0036] The outer casing may advantageously include at least one fastening element.

[0037] According to another aspect, claim 11 proposes a method for manufacturing the breast prosthesis as defined above, by molding and / or 3D printing the prosthesis in one piece or the constituent elements of the prosthesis in several pieces, preferably by molding and / or 3D printing the flexible internal skeleton and / or the flexible outer shell in one piece or in several pieces; more preferably still by molding and / or 3D printing the bracing structure and / or the inner cap, and / or the peripheral skirt in one piece or in several pieces; said method further comprising: ◆ advantageously, the filling of the first and / or second filling chamber, with the first and second filling fluid, respectively; ◆ and, possibly, the assembly of the constituent elements of the prosthesis.

[0038] According to an interesting feature of the invention, all or part of the constituent elements of the prosthesis defining at least one of the two filling chambers are subjected to a sealing treatment, preferably by application of a coating, advantageously a polymer coating, and, even better, a parylene coating. Brief description of the drawings

[0039] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached drawings, on which: [ Fig. 1 ] - there figure 1 is a perspective representation of an implantable breast prosthesis according to a first embodiment, [ Fig. 2 ] - there figure 2 is a top-view representation of the breast prosthesis of the figure 1 , [ Fig. 3 ] - there figure 3 is a cross-sectional representation according to the orientation referenced III-III on the figure 2 of the breast prosthesis figure 1 , [ Fig. 4 ] - there figure 4 is a perspective representation of an implantable breast prosthesis according to a second embodiment, [ Fig. 5 ] - there figure 5 is a top-view representation of the breast prosthesis of the figure 4 , [ Fig. 6 ] - there figure 6 is a cross-sectional representation according to the orientation referenced VI-VI on the figure 5 of the breast prosthesis figure 4 . Description of the implementation methods

[0040] THE figures 1 to 3 represent a first method of realizing a breast prosthesis 1 intended to be implanted in the breast of a patient, as part of breast reconstruction surgery or cosmetic surgery.

[0041] The breast prosthesis 1 comprises a flexible inner skeleton 2 and a flexible outer shell 20, both made of a deformable biocompatible material, such as a silicone elastomer with a shore A hardness, for example equal to 30.

[0042] The material is preferably radio-transparent, so as not to interfere with the reading of mammograms and breast ultrasounds.

[0043] The internal skeleton 2 comprises an internal base 4 and an internal cap 5, assembled together in a sealed manner, to define a first filling chamber 3. This chamber is filled, or is filled, with the first filling fluid before assembly. According to an alternative, the internal skeleton 2 could be made in one piece, with the filling of the first chamber with the first fluid preferably occurring simultaneously with the manufacture of the internal skeleton 2.

[0044] The inner base 4 has opposing internal surfaces 4a and external surfaces 4b and a contour which, in the 1st embodiment shown, extends around a base axis A while being centered on the base axis A. In particular, the contour is circular.

[0045] The inner cap 5 is integral with the inner base 4 (for example after joining by gluing or welding), such that an internal surface 5a of the inner cap 5 is disposed opposite the internal surface 4a of the inner base 4. In particular, the internal surface 4a of the inner base 4 is integral with the internal surface 5a of the inner cap 5, (for example after joining by gluing or welding), at a distance from a peripheral edge 6 of the latter, such that the inner cap 5 has a peripheral skirt 7 between its peripheral edge 6 and the contour of the inner base 4.

[0046] A bracing structure 10 is interposed between the internal surfaces 4a, 5a of the inner base 4 and the inner cap 5, to space the inner cap 5 from the inner base 4, in such a way: □ that the inner base 4 can be globally flat when it rests on a flat support surface, in the absence of external stress, □ and that an external surface 5b of the inner cap 5, opposite the internal surface 5a, has a convexity.

[0047] The bracing structure 10 comprises an arrangement of flexible bracing walls 11, each having first 12 and second 13 opposite edges, fixed, respectively, to the internal surfaces 4a, 5a of the inner base 4, and the inner cap 5. In order to maintain the inner skeleton 2 in the desired shape, namely a flat inner base 4 and a convex inner cap 5, the first edge 12 of each of the bracing walls 11 extends perpendicularly to the base axis A, and the second edge 13 is aligned with the first edge 12 along the base axis A. Furthermore, the second edges 13 of the bracing walls 11 have curvatures adapted to obtain the convexity of the external surface 5b of the inner cap 5. In the first embodiment shown, the bracing structure 10 has a vertex centered on the base axis A. giving the internal skeleton 2 a dome shape.

[0048] The bracing walls 11 are arranged to define a plurality of compartments 14, each having compartment axes B parallel to the base axis A. In the first embodiment shown on the figures 1 to 3 , the arrangement of bracing walls 11 forms a three-dimensional honeycomb bracing structure 10, whose cells have, in this example, a hexagonal shape in cross-section in a plane perpendicular to the base axis A. These cells are compartments 14, preferably sealed between each other.

[0049] The outer envelope 20 of the prosthesis 1 comprises an outer base 22 and an outer cap 23 in one piece or joined together in a sealed manner to delimit a second filling chamber 21 surrounding the inner skeleton 2 and filled with the 2nd filling fluid.

[0050] The peripheral skirt 7 of the inner skeleton 2 is attached to an internal surface 20a of the outer shell 20, such that the external surface 4b of the inner base 4 is opposite an internal surface 22a of the outer base 22. The second filling chamber 21 then has a first compartment 21a between an internal surface 23a of the outer cap 23 of the outer shell 20, the external surface 5b of the inner cap 5 and the peripheral skirt 7, and a second compartment 21b between the internal surface 22a of the outer base 22 of the outer shell 20, the external surface 4b of the inner base 4 and the peripheral skirt 7.

[0051] The first filling chamber 3 of the inner skeleton 2 is filled with a first fluid, and the second filling chamber 21 of the outer shell 20 is filled with a second fluid. The first 21a and second 21b compartments communicate with each other via holes 25, for example, equidistant, provided in the peripheral skirt 7 of the inner skeleton 2. The second filling fluid can thus circulate between these two compartments 21a and 21b. The outer base 22 and the outer cap 23 are configured so that the inner base 4 and outer base 22 are parallel to each other at rest and when the prosthesis filled with the two fluids is placed on a flat support. In this resting position, the outer surface 23b of the outer cap 23 of the outer shell 20 has a convexity.

[0052] The first fluid is gaseous. This is, for example, air, preferably at a pressure equal to atmospheric pressure.

[0053] The second fluid is, for example, an aqueous solution of hyaluronic acid at a concentration of around 3% by mass.

[0054] To improve the retention in position of the breast prosthesis 1, the latter may include, preferably on the outer shell, one or more fixing elements, for example, in the form of fixing tabs.

[0055] The breast prosthesis 1 thus produced has mechanical properties, such as flexibility, support, resistance and density, giving it a satisfactory firmness in terms of aesthetics and touch.

[0056] The bracing structure 10 can have different sizes of alveoli, depending on whether it is central or peripheral relative to the basic axis A, for example, to create an internal skeleton 2 that is more or less dense, giving different flexibilities to palpation.

[0057] Breast prosthesis 1 is also compressible and deformable so that it can be partially crushed and flattened for implantation through an incision between 2 cm and 10 cm, preferably between 3 cm and 6 cm and, even more preferably, around 4 cm.

[0058] In relation to figures 3 to 6 , a second embodiment of the breast prosthesis 1' is described.

[0059] In this second embodiment, the breast prosthesis 1' differs from the first embodiment only in the arrangement of the flexible bracing walls 11' of the bracing structure 10' of the internal skeleton 2'. The other characteristics, unchanged from the first embodiment, are not described again here. Reference should therefore be made to the description given previously for further details.

[0060] Bracing walls 11', of which there are eight in the figures, extend radially from the base axis A, from a hollow cylindrical trunk 26', centered on the base axis A. This arrangement defines a central compartment 14' and eight peripheral compartments 14' around the central compartment 14'.

[0061] According to one variant, the cylindrical hollow trunk 26' can be replaced by a solid trunk of variable diameter. The minimum diameter can correspond to the dimension of the junction of the walls 11' around the base axis A.

[0062] According to a preferred feature, the 1.1" breast prosthesis includes two 30.30" attachment tabs, each with an eyelet allowing for fixation, e.g., by stitching, of the prosthesis after implantation. As shown on the figures 2 And 5The two 30' and 30' fixing tabs are symmetrical with respect to the diametral sagittal plane of the prosthesis, which is intended to be substantially parallel to the sagittal plane of the patient after implantation of the 1,1' prosthesis. The angle formed by each 30' and 30' fixing tab with respect to the diametral sagittal plane of the prosthesis is preferably between 45 and 15 degrees, and even more preferably on the order of 30°.

[0063] Alternatively, any other arrangement of one or more flexible bracing walls 11,11' spacing the inner cap 5 from the inner base 4, giving a convexity to the inner cap 5, could be provided.

[0064] Thus, the bracing walls could be one or more rings, including circular, oval or elliptical, continuous or discontinuous, concentric(s) with axis A or not, or any other wall shapes.

[0065] Regarding the manufacturing process for the 1.1" breast prosthesis, it refers to known molding or 3D printing technologies using elastomers, for example, silicones with a Shore A hardness of around 30 after cross-linking / curing. Molding includes, in particular, injection molding, pressing, stamping, etc.

[0066] The different component parts of the 1,1' breast prosthesis can be manufactured separately, in a single block or in several subunits.

[0067] Since the 1.1" breast prosthesis is not made in one piece, the manufacturing process includes assembly operations of the different constituent elements or subunits, by welding and / or gluing.

[0068] To make the different walls separating compartments 14,14', 21a,21a', 21b, 21b' watertight or to improve the watertightness, a coating treatment for a polymer, for example parylene, is implemented.

[0069] The manufacture of the prosthesis 1,1' preferably incorporates the filling of the first filling chamber with a 1st gaseous fluid, such as air at atmospheric pressure and the filling of the 2nd filling chamber consisting of the 2 compartments 21a,21a', 21b, 21b', surrounding the inner cap 5,5', with a 2nd fluid formed by a liquid, namely for example an aqueous solution of hyaluronic acid at 2 or 3% by mass.

Claims

1. Implantable breast prosthesis (1; 1') comprising: - a flexible inner skeleton (2; 2') delimiting a first filling chamber (3) filled with a first fluid, said inner skeleton (2; 2') comprising: • an inner base (4) having opposite inner (4a) and outer (4b) surfaces, • an inner cap (5) having inner (5a) and outer (5b) surfaces and secured to the inner base (4) in such a way that the inner surfaces (4a; 5a) of the inner base (4) and of the inner cap (5) face one another, • a spacing structure (10; 10') disposed between the inner surfaces (4a, 5a) of the inner base (4) and of the inner cap (5) and configured to space the inner cap (5) from the inner base (4), in such a way that the outer surface (5b) of the inner cap (5) has a convexity, - a flexible outer envelope (20, 20') delimiting a second filling chamber (21, 21') filled with a second fluid, said second filling chamber (21, 21') surrounding the inner skeleton (2; 2').

2. Breast prosthesis (1; 1') according to claim 1, wherein: - the inner base (4, 4') has a contour around a base axis (A); - and the spacing structure (10; 10') comprises at least one flexible spacing wall (11, 11') having opposite first (12, 12') and second (13, 13') edges secured, respectively, to the inner surfaces (4a, 4a', 5a, 5a') of the inner base (4, 4') and of the inner cap (5, 5').

3. Breast prosthesis (1; 1') according to claim 1 or 2, wherein the spacing structure (10; 10') comprises an arrangement of spacing walls (11; 11') configured to define a plurality of compartments (14; 14') in the first filling chamber (3).

4. Breast prosthesis (1; 1') according to any one of claims 1 to 3, wherein the spacing structure (10; 10') has an apex centred on the base axis (A).

5. Breast prosthesis (1; 1') according to any one of claims 1 to 4, wherein: - the outer envelope (20, 20') has an inner surface oriented towards the second filling chamber (21, 21') and an outer surface opposite the inner surface; - the inner skeleton (2; 2') has a peripheral skirt (7, 7') secured to the inner surface of the outer envelope (20, 20'), in such a way that the second filling chamber (21, 21') comprises: > a first compartment (21a, 21a') between the inner surface of the outer envelope (20, 20'), the outer surface (5b, 5b') of the inner cap (5, 5') and the peripheral skirt (7, 7'), > and a second compartment (21b, 21b') between the inner surface of the outer envelope (20, 20'), the outer surface (4b, 4b') of the inner base (4, 4') and the peripheral skirt (7, 7').

6. Breast prosthesis (1; 1') according to claim 5, wherein the first (21a, 21a') and second (21b, 21b') compartments of the second filling chamber are in fluid communication, preferably by means of holes (25, 25') formed through the peripheral skirt (7, 7'), said holes (25, 25') being more preferably evenly distributed.

7. Breast prosthesis (1; 1') according to at least one of the preceding claims, characterised in that it comprises, preferably on the outer envelope, one or more fastening elements or tabs.

8. Breast prosthesis (1; 1') according to any one of claims 1 to 7, wherein the first and second fluids are different from one another, the first fluid being gaseous at a temperature greater than or equal to 30°C and at atmospheric pressure, the second fluid being liquid at a temperature greater than or equal to 30°C and at atmospheric pressure.

9. Breast prosthesis (1; 1') according to claim 8, wherein the first fluid comprises air, preferably at a pressure equal to atmospheric pressure.

10. Breast prosthesis (1; 1') according to claim 8 and / or 9, wherein the second fluid is a hyaluronic acid solution, preferably at a concentration comprised between 1% by mass and 5% by mass, and still more preferably between 2% by mass and 4% by mass.

11. Method for manufacturing the breast prosthesis (1; 1') according to any one of claims 1 to 10, by moulding and / or 3D printing the prosthesis in a single piece or the constituent elements of the prosthesis in several pieces, preferably by moulding and / or 3D printing the flexible inner skeleton (2; 2') and / or the flexible outer envelope (20) in a single piece or in several pieces; still more preferably by moulding and / or 3D printing the spacing structure (10; 10') and / or the inner cap (5, 5'), and / or the peripheral skirt (7, 7') in a single piece or in several pieces; said method further comprising: • advantageously, filling the first (3, 3') and / or the second filling chamber (21, 21') with the first and the second filling fluid, respectively; • and, optionally, assembling the constituent elements of the prosthesis (1, 1').