Variable volume prosthetic assembly

[57] ABSTRACT

A surgically implantable variable volume prosthetic assembly including a first flexible implantable prosthesis having an outer shape approximating that of the human breast, a second flexible container or reservoir having a volume greater than the volume of the first prosthesis with a silicone gel completely filling the reservoir and means for sealingly connecting the reservoir to the prosthesis, the reservoir being squeezed to force the gel into the prosthesis after implantation, the connecting means can be severed and sutured to the back of the prosthesis or a valve can be provided in the connecting means to seal the reservoir and implant during storage and after inflation.

Claims, 8 Drawing Figures

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PATENTED HAY 2 01975

3.883,902

SHEET 1 OF 2

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FIG. 4

PATENTED HAY 2 01975

3,883,902

SHEET 2 OF 2

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FIG. 5

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FIG.7

3,883,902

VARIABLE VOLUME PROSTHETIC ASSEMBLY

RELATED APPLICATION

This application is a continuation-in-part of my copending application entitled “Variable Volume Prosthetic Assembly”, U.S. Ser. No. 281,150, filed Aug. 16, 1972, and now abandoned.

BACKGROUND OF THE INVENTION

Implantable prostheses of the type shown in U.S. Pat. No. 3,665,520, entitled “Surgically Implantable Breast Prosthesis” are prefilled to the desired shape with a silicone gel. In order to implant a prosthesis in the body, it is necessary to make an incision of a length sufficient to insert the prefilled prosthesis through the incision into the body. Once implanted, the volume of this prosthesis could not be changed without removing the prosthesis. Empty flexible containers have been implanted in the body and subsequently filled by injecting liquids or a gel into the container. However, difficulties have been encountered in inserting silicone gels into the containers having the required viscosity. The equipment required to fill this type of implant is also more complicated, increasing the difficulty in maintaining operating room standards.

SUMMARY OF THE INVENTION

The variable volume prosthetic assembly of the present invention overcomes the above problems by using a closed system which includes a reservoir for storing the gel attached to an empty container. The silicone gel is thus sealed into the closed system at the point of manufacture. The entire system can be shipped ready for use and autoclaved at the point of manufacture. The flexible container for the prosthesis can be implanted empty in a rolled up or flattened condition and therefore can be inserted into a much smaller incision. Once the empty prosthesis has been implanted, it is a simple step to squeeze the reservoir to force the silicone gel from the second container into the prosthesis. The second container is connected to the first container by a tube which is secured and sealed to the two flexible containers. Once the first or implanted container has been filled to the desired fullness, the tube can be tied and cut, folded over and tied, and then sutured to the back of the flexible container. This closed system eliminates the necessity of using additional equipment to insert the gel into the prosthesis after implanting and as a consequence simplifies the entire operation. The tube can also be provided with a valve or plug for automatically sealing the container and reservoir during storage and after implanting the container in the body.

DRAWINGS

FIG. 1 is a plan view of the back of the prosthetic assembly of this invention;

FIG. 2 is a side view of the invention showing the tubular connection between the prosthesis and the reservoir;

FIG. 3 is a view of the prosthesis and the reservoir after the gel has been forced into the prosthesis;

FIG. 4 is a partial view of the prosthesis showing the prosthesis after the tubular connection has been sealed and folded against the back of the prosthesis;

FIG. 5 is a side view of the invention showing a oneway check valve at the end of the connector tube;

FIG. 6 is an alternate embodiment of the invention wherein a plug or valve is used to close both the container and reservoir;

FIG. 7 is a view similar to FIG. 6 showing the connecting tube cut off and the valve cut off to seal both the container and the reservoir; and

FIG. 8 is a view of the plug.

DESCRIPTION OF THE INVENTION

The implantable prosthetic assembly 10 of the present invention as seen in FIG. 1 includes a first flexible container or shell 12 and a second flexible container or reservoir 14. The containers 12 and 14 are connected by means of a tube 16 which is formed as an integral part of the two containers 12 and 14. The second container 14 is filled with a silicone gel 18 and the entire assembly autoclaved at the time of manufacture. The silicone gel 18 is transferred to the implanted shell 12 by squeezing the reservoir 14 to force the silicone gel 18 into the shell 12.

The first container or shell 12 is formed from an implantable material such as an organopolysiloxane compound as set forth in U.S. Pat. No. 3,665,520 or from a silicone rubber such as General Electric Elastomeric Resin 7000. The G. E. Elastomer resin contains R₂SiOi/2 groups, and small amounts of vinyl R₂SiO, where R represents methyl groups. This elastomer is known to have characteristics such as softness and resiliency that can be controlled to approximate that of the human body. The container 12 can be made to approximate any shape and as shown is formed with a front surface 11 having the general shape of a natural breast and a back surface 22 which is shaped to follow the general contour of the chest wall.

The second container or reservoir 14 can be formed from the same material as the first container 12 or from a medical grade material such as silicone polycarbonate copolymer. The reservoir 14 preferably has a volume equal to or greater than the volume of the first container 12. If desired, graduations 24 can be provided on the surface of the reservoir 14 to indicate the amount of silicone gel 18 available to be forced into the prosthesis 12.

The second container 14 is filled with the silicone gel 18 such as set forth in U.S. Pat. No. 3,665,520. As an example, a gel containing a major component of R₂SiO, a minor component of vinyl R₂SiO_1/2 and small amounts of R vinyl R₂SiO and R₃SiO_1/2 has been used successfully. Other gels approved for medical use can be used if desired.

The reservoir 14 and shell 12 can be rotationally cast on a mold of the required shape. The mold is dipped in the liquid elastomer and rotated to form the reservoir or container on the outside of the mold. The mold is repeatedly dipped and rotated to cure the elastomer until the assembly has the desired wall thickness. The wall of the containers 12 and 14 formed of this material has little if any rigidity and is very soft and flexible in compression but is known to have a tensile strength satisfactory for this use.

The two containers 12 and 14 are interconnected by means of a tube 16. In this regard, the tube 16 is provided at one end with a flange 17 which is connected to the inside of the container 12. The other end of the tube 16 is bonded to an opening 15 provided in the res

3,883,902 ervoir 14. The tube 16 can be reinforced with a fabric 19 such as Dacron or nylon if desired.

The shell 12 is implanted by inserting the shell 12 through a small incision in the patient. The shell can be rolled up and inserted as a tube and the unrolled after implanted or inserted flat, whichever is preferred. The second container or reservoir 14 as seen in FIG. 3 is then squeezed or rolled to force the gel 18 from the reservoir 14 through the tube 16 into the shell 12 to fill the prosthesis. The amount of silicone gel 18 forced into the prosthesis can be determined by observing the graduations 24 provided on the wall of the reservoir 14 and also observing the extent of expansion of the body. After the prosthesis 12 has been filled to the desired size, the tube 16 is tied off with a surgical thread 26. The tube is then cut at 28 to remove the reservoir. The remaining portion of the tube is then folded at the tie thread 26 and sutured or tied by means of a thread 27 to hold the tube in place on the back 22 of the prosthesis 12 as seen in FIG. 4. It should be noted that during this entire procedure, the silicone gel 18 is sealed in the reservoir and is never exposed to the atmosphere and will remain sterile during the entire operation.

Referring to FIG. 5, means are shown for preventing back flow of gel from the first container 12 to the second container or reservoir 14. Such means is in the form of a one-way valve 30 provided at the end of the tube 16 and within the first container 12. The one-way valve shown is a duck bill type valve having upper and lower resilient flaps 32 and 34 extending into the container 12. The valve 30 allows for the admission of gel into the container 12 but will prevent back flow of gel from the container 12.

Referring to FIGS. 6 and 7, an alternate embodiment of the invention is shown which includes means for sealing the container 12 from the reservoir 14 and for closing both the container and reservoir after implant. In this embodiment, a resilient tube 40 made of medical grade material is shown having one end 42 sealed to the reservoir 14 by means of a transverse tube 45 and the other end 44 sealed directly to the opening 47 in the container 12. In this regard, the end 44 is provided with a flange 46 which extends radially outwardly from the tube 40 and is sealed by means of a suitable adhesive to the wall of the conainer 12. An enlarged diameter section 48 is provided within the container 12 at the end 44 of the tube 40. The enlarged diameter section 48 includes an opening 50 at the inner end to allow for the flow of gel through the section 48 into the container. The other end of the tube 40 is closed by means of enlarged section 54.

The tube 40 is closed or blocked by means of a plug 32 which is normally located in tube 40 to prevent gel from flowing in the container 12 during storage. The plug 56 is moved into the closed enlarged section 54 formed on the end 42 of the tube 40 after the container 12 has been implanted to allow for the flow of gel from the reservoir into the container.

The plug 52 includes a head 56 having an outer diameter substantially equal to the inner diameter of the section 48, body 58 having a diameter substantially equal to the diameter of the tube 40 and an enlarged member 57 having a diameter substantially equal to the diameter of the head 56. A slot or groove 60 is provided in the body 58 to form a reduced diameter cut-off section 59 between the body 58 and member 57. The body 58 should have a length long enough to extend beyond flange 46 when the head 56 is seated in the section 48.

The slot 60 is used as a guide to determine the location of the point-of cut-off of the tube 40 and to simplify cutting the plug by providing the reduced diameter cutoff section 59.

In regard to this last, after the implant 12 has been filled with the gel, the plug 52 is moved from the section 54 through the tube 40 by squeezing the section 54 and tube 40 behind the plug 12. The gel acts as a lubricant and allows the plug 52 to slide freely into the section 48. The head 56 of the plug 52 will fit snugly within section 48 blocking the flow of gel from the reservoir. The tube 40 and reduced section 59 are then cut at the slot 60. The section 57 remaining in the tube 40 will act as a plug preventing any gel in the tube 40 from flowing out of the tube 40 after the reservoir 14 has been removed.

RESUME

The variable volume prosthetic assembly of this invention provides a simple sterile method for implanting a prosthesis. Once filled, the reservoir and container can be stored and shipped without any fear of contamination. The incorporation of a self-sealing valve or plug into the tube eliminates the possibility of any gel escaping from the implant. After the container or shell has been implanted, the shell can be filled to the extent required to fill out the portion of the anatomy to be augmented. Although prostheses of the type disclosed herein are more commonly used as a breast prosthesis, the prosthesis or container can also be used in other parts of the body either as a replacement or augmentation prosthesis.