FR2726173A1 - Fluid-filled pouch for implantation in breast replacement prosthesis - Google Patents

Abstract

The prosthesis consists of a pouch (1) of flexible synthetic material which may be filled with a biocompatible fluid. The pouch has a rear base surface (2) which is approximately vertical, and a hemispherical front surface (3). At least a lower region (3'a) of the periphery of the front surface has a lower elasticity than the remainder of the periphery. The elasticity of the entire periphery of the front surface is lower than that of the central region which it surrounds. The variations in elasticity are achieved by corresponding variations in the wall thickness of the pouch, such that the regions of highest elasticity are those with the lowest wall thickness.

Description

EXPANSION PROSTHESIS FOR
TO BREAST RECONSTRUCTION
The present invention relates to an expansion prosthesis intended for breast reconstruction, and more particularly to such a prosthesis comprising a pocket capable of being filled, in particular with physiological saline, the envelope of said pocket being made of a flexible synthetic material and forming a substantially vertical posterior base portion when the patient wearing said prosthesis is standing or seated, and an anterior portion of generally hemispherical shape and having a peripheral area bordering the base portion and a central area.

 We already know expansion prostheses used in cosmetic or reconstructive surgery. For example, document EP-A-0181720 describes an expansion prosthesis more particularly intended for the treatment of baldness.

Such prostheses are placed under a tissue to be expanded for any therapeutic reason, then are gradually filled, generally with physiological saline, over a period typically ranging from a few weeks to a few months. They are then removed to be replaced by a final prosthesis, which is the case in reconstruction
breast tissue, unless the expanded tissue flap is itself used as a prosthesis as in the case of baldness treatment.

 The prosthesis of the document mentioned above has an envelope whose thickness is variable so that after filling, it can still be inflated by expansion of its thinnest parts.

One could therefore have thought of making a breast expansion prosthesis whose bottom of the anterior part is thinner so as to expand more than the top, and thus form a cavity of suitable shape for the final prosthesis.

 In fact, such a provision is not satisfactory. Indeed, the patient wearing the prosthesis is most often in a standing or sitting position, so that gravity tends to deform the prosthesis in its lower part. Tissue expansion then does not occur as desired.

 The present invention aims to overcome these drawbacks.

 To this end, the subject of the invention is an expansion prosthesis intended for breast reconstruction, comprising a pocket capable of being filled, in particular with physiological saline, the envelope of said pocket being made of a flexible synthetic material and forming a substantially vertical posterior base portion when the patient wearing said prosthesis is standing or seated, and an anterior portion of generally hemispherical shape and having a peripheral area bordering the base portion and a central area, characterized in that at least the lower portion of said peripheral zone has a lower elasticity than that of said central zone.

 This lower portion of the peripheral zone, of lower elasticity, is opposed, standing or sitting, to the weight of the physiological serum contained in the pocket, and consequently to the deformation of the surrounding tissues. The invention therefore allows tissue expansion of suitable shape.

 In a particular embodiment of the invention, substantially all of said peripheral zone has a lower elasticity than that of said central zone.

 Preferably, the elasticity of the front part of the envelope gradually decreases from its central zone towards the edge of its peripheral zone.

 The decrease in elasticity of the envelope is preferably obtained by an increase in its thickness.

 In a particular embodiment of the invention, the base has the same characteristics as the edge which is adjacent to it of said peripheral zone.

 The texture of said front part of the envelope can be more or less fine depending on whether one is in a more or less elastic zone.

A particular embodiment of the invention will now be described, by way of nonlimiting example, with reference to the appended schematic drawings in which:
- Figure 1 is a sectional view along line II of Figure 2 of a prosthesis according to the invention; and
- Figure 2 is a front view.

 The prosthesis shown in the drawings comprises a pocket 1 provided with an orifice (not shown) capable of being connected, via a catheter, to an implantable injection site through which the pocket can be filled with a fluid such as physiological saline. This pocket consists of an envelope made of synthetic material such as silicone.

 The pocket 1 consists of a substantially flat base part 2 and a generally hemispherical part 3, joined along their respective edges. When the pocket 1 is implanted on the patient, the base part 2 is placed in the posterior position and the hemispherical part 3 is placed in the anterior position.

 The base part is here arranged to be substantially inextensible.

On the other hand, the hemispherical part has a variable thickness allowing it to be more or less elastic from one zone to another.

 In the present case, the peripheral zone of the hemispherical part, being at the edge of the posterior part, is thicker than the central zone. It is also of a less fine texture. These two zones have been shown schematically in 3 'and 3 "respectively in FIG. 2, but it will be observed in FIG. 1 that in fact, the thickness of the envelope decreases regularly from the periphery towards the center of the hemispherical part 3 .

 This difference in thickness results in a difference in elasticity, the peripheral zone being less elastic than the central zone. In particular, the lower portion 3 ′ a of this peripheral zone opposes, at this point, an excessive tissue expansion which would otherwise be caused by gravity when the patient is in a standing or sitting position. As for the upper portion 3'b of the peripheral zone, it promotes expansion in the central zone.

Claims (7)

 1- Expansion prosthesis intended for breast reconstruction comprising a pocket (1) capable of being filled, in particular with physiological saline, the envelope of said pocket being made of a flexible synthetic material and forming a posterior base part (2 ) substantially vertical when the patient wearing said prosthesis is standing or seated, and an anterior part (3) of generally hemispherical shape and having a peripheral zone (3 ') at the edge of the base part and a central zone (3 ") , characterized in that at least the lower portion (3'a) of said peripheral zone has a lower elasticity than that of said central zone.  2- Expansion prosthesis according to claim 1, wherein substantially all of said peripheral zone has a lower elasticity than that of said central zone.  3- An expansion prosthesis according to any one of claims 1 and 2, in which the elasticity of the front part of the envelope gradually decreases from its central zone towards the edge of its peripheral zone.  4- expansion prosthesis according to any one of claims 1 to 3, wherein the decrease in the elasticity of the envelope is obtained by an increase in its thickness.  5- Expansion prosthesis according to any one of claims 1 to 4, wherein the base has the same characteristics as the edge which is adjacent to it of said peripheral zone.  6- expansion prosthesis according to any one of claims 1 to 5, wherein the texture of said anterior part of the envelope is less fine in its least elastic areas than in its most elastic areas.  7. An expansion prosthesis according to any one of claims 1 to 5, in which the texture of said anterior part of the envelope is finer in its less elastic zones than in its most elastic zones.