Note: Descriptions are shown in the official language in which they were submitted.
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DEFLATABLE TISSUE AUGMENTATION PROSTHESIS
This invention relates to a tissue augmentation
prosthesis which is particularly suited for mammary augmentation,
and is more particularly concerned with an implantable prosthesis
that may be inflated with liquid after implantation and subse-
quently deflated by removal of liquid to relieve the effects of
spherical contracture of surrounding tissue on the prosthesis.
Mammary augmentation prostheses are normally divided
into two general catagories: (1) the external prosthesis to be
attached to or carried adjacent the outside of the body, as
by carrying in a brassiere or the like; and (2) the implantable
prosthesis that is surgically implanted beneath the skin of
the body either between the chest wall and the mammary gland, as
in the case of cosmetic augmentation or replacing the mammary
gland following a mastectomy.
Prostheses designed for external use have ~een made of
numerous materials and have included containers filled with
various materials in an effort to provide a total effect similar
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to a normal human breast. Problems associated with the
implanting of a prosthesis are not encountered with those
prostheses designed for external application. Consequently,
a wider latitude of design and implant material is available
for such external application.
The implantable prosthesis on the other hand must meet
certain rigid standards and requirements because of the implan-
tation of the prosthesis beneath the skin of the patient.
Silicone gel has been found to be a desirable material to
approximate normal contours and tissue characteristics, but
there have been problems in the use of silicone gel as a sub-
cutaneous implantation. It has been determined to be objec-
tionable and undesirable to inject silicone gel or fluid sub-
cutaneously so that the gel or fluid itself is in contact with
body tissue. Consequently, the gel has been placed within a
silicone rubber container which retains the gel within the con-
tainer and prohibits introduction of the gel into the body of
the patient. While such a prosthesis when properly implanted
effects augmentation of a breast, in time tissue surrounding the
prosthesis may contract and cause a spherical contracture of the
prosthesis into a relatively rigid and tense structure which is
spherical in shape and relatively immovable, causing thereby a
superior pole convexity of the upper surface of the breast and
a firm, aesthetically undesirable breast. As the tissues around
the implant contract, the fixed volume of the silicone gel mater-
ial within its silicone rubber container is forced into a shape
having the smallest possible surface area. The shape of the
prosthetic implant becomes spherical thereby causing the breast
to assume an abnormal spherical appearance with superior pole
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convexity. Once implanted it is not possible to remove a portion
of the silicone gel material by insertion of a hypodermic needle
through the breast of the patient and into the prosthesis because
the silicone gel material is so thick, viscous and cohesive
that it is not easily removed through the hypodermic needle.
In addition puncture of the container for the gel by the needle
would permit undesirable and objectionable leaking of the gel
into the body of the patient.
Additionally, it has been determined that silicone gel
feels slightly cooler to the touch than normal body temperature
and therefore feels somewhat uncomfortable under certain
circumstances when implanted beneath the skin.
The present invention overcomes the above mentioned
and other problems with prior art implantable prostheses by
providing a prosthesis which may be selectively enlarged prior
to or during implant procedures and subsequently reduced in
size following spherical contracture of the tissue surrounding
the prosthesis. Enlargement of the prosthesis is obtained
through the addition of saline solution or other suitable fluid
to the prosthesis, such a solution being easily handled by con-
ventional hypodermic syringe equipment.
In one broad aspect, the invention comprehends an
implantable augmentation prosthesis which includes a capsule
having a substantially fixed volume of a soft material suitable
for forming the desired prosthesis augmentation, and means for
adjusting the size of the prosthesis which comprises a sac sub-
stantially surrounding the capsule and means for permitting the
inflation of the sac with a liquid.
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The invention further comprehends an augmentation
prosthesis for subcutaneous implantation beneath the skin of a
patient, which comprises an exterior sac containing an interior
capsule which occupies less than the entire volume of the
sac. The capsule contains a fixed volume of soft material suit-
able for forming the desired prosthesis augmentation, and the
sac includes a valve means for selective addition of a liquid
into the sac.
These and other features and advantages of the present
invention will become apparent from consideration of the
following specification when taken in conjunction with the
accompanying drawings in which:
Fig. 1 is a perspective view showing the posterior
side of a prosthesis made in accordance with the present
invention;
Fig. 2 is a cross-sectional view taken substantrally
along the line 2-2 in Fig. l;
Fig. 3 is a somewhat schematic illustration showing
a cross-sectional view of the prosthesis of Fig. 1 implanted
in a patient;
Fig. 4 is a view similar to Fig. 1 showing a modified
form of the prosthesis according to the present invention; and
Fig. 5 is a cross-sectional view taken substantially
along the line 5-5 in Fig. 4.
Referring now to the drawings, and more particularly
to Figs. 1, 2 and 3, there is shown a surgically implantable
mammary augmentation prosthesis comprising an outer sac 11 and
an inner capsule 12 contained within the outer sac and occupying
less than the entire volume of the outer sac. The volume of
outer sac 11 is normally at least 75 cc and rarely more than
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200 cc, but may be as low as 25 cc, this volume being in excess
of the volume occupied by inner capsule 12. The walls of the
sac and the capsule are constructed of a soft, flexible material
such as silicone rubber compound. The walls of the inner capsule
are impervious to the material 13 contained therein and retain
the material within the capsule. The walls of the outer sac are
semi-permeable and permit an exchange of fluid from within the
sac to the tissue surrounding the prosthesis without loss of
effective volume. According to one optional embodiment of the
present invention, it is possible to place medication within the
liquid contained in the outer sac and thereby achieve a long
term continuous application of medication to the area surrounding
the prosthesis. Of course, the walls of the outer sac may also be
so thick that they are also impervious to all liquids but it is not
necessary or critical that such wall thickness be present in the
walls of the outer sac. The primary criterion for the walls of
the present invention are that the inner capsule contain the
material therein and that the complete prosthesis be soft, pliable
and comfortable while also causing the prosthesis to assume natural
body contours.
The walls of both the inner capsule and outer sac have
a substantially flat rear wall and the capsule and sac in this
embodiment are bonded together in a common area 14 along their
rear walls to form a posterior side for the prosthesis. The
front walls of the sac and capsule assume an outwardly convex
shape closely approximating the shape of human breasts. Within
the central portion of the posterior common area 14 of the
prosthesis, there is a fixedly positioned attachment patch of
open cell foam flexible plastic material 15. When in position
following implant, tissue may grow into patch 15 to anchor the
prosthesis in position. It should be understood that the presence
of patch 15 is not required for the present invention since
it is possible in some applications to delete patch 15 and
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achieve satisfactory results. The use of and need for anchor
patches in augmentation prosthesis is well known to those of
ordinary skill in this art and it is felt that further discussion
of this element is unnecessary.
Capsule 12 is permanently filled completely with a high
or low viscosity material 13 such as silicone gel as a high
viscosity material or sterile saline solution as a low viscosity
material to simulate the contours and characteristics of a human
breast. Currently, silicone gel material is most popular for
use in implantable mammary augmentation prostheses. However, it
is recognized that other materials maybe equally suitable so long
as the consistency and viscosity of the implant material closely
simulates the contours and characteristics of the human breast.
Conventionally, mammary augmentation prostheses contain from
100 cc to 300 cc of silicone gel material. Of course, more
or less such material could be employed if desirable.
Outer sac 11 is selectively filled with a relatively
thin liquid 17 such as sterile, normal or isotonic saline solu-
tions or other typical liquids which are compatable with the
human body. Typically, from 7S to 125 cc of saline solution are
injected into sac ll. It should be understood of course that
more or less such solution could be used when desirable within
the limits of the capacity of the sac. Filling of outer sac ll
is accomplished by means of fllling valve 16. Valve 16 includes
tube 18 which passes through and is sealed along its outer edges
to posterior wall l9 of sac ll. Attached to the exterior end
of tube 18 is funnel section 20 and attached to the inner end
of tube 18 is a flap valve 22. Flap valve 22 is formed integrally
with tube 18 and is quite flexible and soft to the touch. Flap
valve 22 lies generally between the posterior wall 19 of sac 11
and the posterior wall 21 of capsule 12.
Funnel section 20 of vlave 16 is provided for
receiving a long cannula which is attached to the end of a syringe
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or other such liquid displacement device. The funnel and tube
18 aid in properly quiding the cannula into flap valve 22 to
open the valve and allow liquid to be introduced through the
cannula and into sac 11.
As shown in Fig. 3, when properly oriented beneath
the skin 51 of the patient, the patch 15 of the prosthesis lies
adjacent the chest wall 50 of the patient so that tissue may
grow into the patch and anchor the prosthesis. Additionally,
the prosthesis should be oriented so that valve 16 is in a lower-
most posterior position so that the implant overlays the valveand aids in its concealment from sight and touch. Preceeding
closure of the surgical incision beneath the augmented breast,
the exterior portion of tube 18 containing funnel section 20
is cut from valve 16 to present a relatively smooth and attractive
appearance to the posterior section of the prosthesis.
The procedure contemplated for implant of the prosthesis
according to the present invention varies depending on whether the
total procedure involves a mastectomy removal of breast tissue
or simply mammary augmentation for cosmetic purposes. For the
purpose of explanation the following discussion is based on
mammary augmentation with no consideration being given to
procedures or modifications necessary due to the performance of
a mastectomy operation.
Following preparation of the patient, the implantation
procedure includes marking the dissection line in the infra-
mammary crease, making the incision and dissection and achieving
hemostasis within the compartments formed between the mammary
gland and the chest wall. Prior to insertion of the prosthesis
10 into the compartment, the competence of the sac 11 is tested
by in]ecting a predetermined quantity of saline solution into the
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sac 11 through the valve 16. If it is found that the sac 11
is properly sealed, the saline solution is removed, and the
prosthesis is placed into the compartment while the sac 11 is
in a deflated condition.
After the prostheses have been appropriately placed
within the compartments (assuming bilateral mammaplasty), the
sacs 11 are inflated by insertion of a cannula into valve 16
and injecting a predetermined quantity of liquid into sac 11.
After the liquid (normally sterile saline solution) has been
injected, the sac 11 is carefully checked and all air is removed,
using the cannula and attached syringe. The cannula is then
removed, the exterior portion of tube 18 is cut off as closely
as possible to the wall of the sac 11, and the prosthesis is
positioned within the compartment. The procedure is completed by
appropriate suturing of the incision.
Following the implantation procedure, the patient has
desirable mammary augmentation. The augmented breasts are
soft and freely movable, closely simulating normal breast contour,
appearance and feel. Also, the patient has desirable straight
line fall from the intraclavicular area to the nipples of the
breasts, and slight superior pole concavity of the upper surface
of the breasts. If there is some hypertrophy in the surgical
wound, it will not be significantly noticeable since the
surgical wound is along the inframammary crease.
During the six months after implantation of the
prostheses, the tissue surrounding the prosthesis may con-
tract, forcing the prosthesis to assume a somewhat spherical -
shape. This spherical contracture produces a rigidity in the
breast along with unsightly superior pole convexity of the
upper surface of the breast. With the prosthesis of the present
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invention, reduction in size of the pros ~ ~sis is easily
accomplished by a relatively uncomplicated office procedure to
decompress the implant and relieve the rigidity and convexity.
The decompression procedure involves evacuatian of a
portion or all of the solution from the outer sac 11. To do so,
a skin anaesthetic is applied in the vicinity of the surgical
wound, and a hypodermic needle is inserted through the patient's
skin and into the sac 11. A syringe is used to evacuate a portion
or all of the solution, and the needle is removed. Following
decompression, a more normal appearance for the breast is
achieved with no spherical contracture of the prosthesis.
Normally, decompression involves removal of all or sub-
stantially all of the solution with the sac 11. If any solution
remains within the sac, it is possible that sac 11 may leak the
remainder thereof through the needle puncture hole in its wall.
Since sac 11 is filled with a sterile saline solution or other
solution which is compatible with the human body, there is no
harm or cause for concern because of such leakage.
It is recognized, however, that in some applications
less than all the liquid within sac 11 will be removed during
decompression of the prosthesis and no leakage will occur.
Furthermore, it is also recognized that in many instances
spherical contracture will be of such a small degree that decom-
pression will not be necessary. In both of these circumstances,
the presence of the solution within sac 11 will have an
advantageous effect for the prosthesis. It is known that
silicone gel presents a rather cold feel to the touch and
under certain circùmstances such a feel is undesirable. It
has been found that the layer of saline solution effectively
insulates the silicone gel and its capsule from contact with the
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patient's skin. In addition, it has been found that saline
solution assumes a temperature more closely approximating that
of human tissue and presents a feel which is more natural to the
touch.
Though the present mammary prosthesis employs a liquid
of a low viscosity, such as saline solution there will be very
little, if any, noise or sloshing produced by agitation of the
water. In order for a liquid such as the water within a saline
solution to generate sound, there must be a shockwave transmitted
through the liquid which causes the surface of the liquid to
be agitated, thereby creating soundwaves. Referring to Fig. 2
of the drawings, it will be seen that a shockwave which might be
created within the sac 11, as the sac is moved, will be trans-
mitted across the sac 11 to engage the capsule 12. The material
within the sac 12 would break-up the shockwave and aid in
dissipating that energy before transmitting the energy of the
shockwave to other sections of the sac 11 and the liquid therein.
An alternative form of the present invention is
demonstrated in Figs. 4 and 5. This embodiment of the invention
includes a prosthesis 30 that comprises an inner sac 31 for
reception of a low viscosity liquid such as saline solution and
an outer capsule 32 filled with a material of either high or
low viscosity such as silicone gel as a high viscosity material
and saline solution as a low viscosity material. As in the
prosthesis 10, the sac and the capsule are bonded together along
their posterior walls in a common area 34, the common area 34
having a substantially centrally located optional attachment
patch 35.
In this embodiment, sac 31 is located within capsule
32 and the valve member 36 must pass through the posterior walls
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38 and 39 of the sac and capsule respectively in the vicinity
of the common area 34. The valve member 36 is substantially
the same as the valve member 16 described in conjunction with
the embodiment of the invention shown in Figs. 1 and 2 and
includes an outer funnel section 40 Eor receiving a cannula or
the like and a flap valve 41 which is disposed within the sac 31.
The procedure for use of the prosthesis 30 is sub-
stantially the same as that described above for the prosthesis
shown in Figs. 1 and 2, except for the obvious difficulty in
decompression. Puncturing of the capsule 32 would be objection-
able and quite undesirable since the material within the capsule
could leak out of the capsule. Consequently, a surgical incision
is made to allow access to the posterior portion of sac 31. While this
procedure is not as desirable as the simple decompression
possible with the prosthesis 10, the resulting decompression
through valve member 36 would reduce the undesirable aspects of
spherical contracture of tissue surrounding the implant.
It will therefore be seen that the prosthesis of the
present invention provides a means for augmentation of a hypo-
plastic breast, or for replacement of breast tissue in the caseof a mastectomy operation. The prosthesis of the present inven-
tion provides the desired amount of augmentation by selection
of the volume of the capsule and the volume of liquid injected
into the sac.
It should be clearly understood that while the present
prosthesis is particularly suitable for mammary augmentation,
it is quite conceivable that other portions of the human body
could be augmented to replace tissue losses or deficiencies. In
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the case of massive wounds to the musculature of arms and legs,
it would be possible to rebuild those areas to more closely
simulate normal body contours.
As a further alternative embodiment of the present
invention it should be understood that the outer wall of sac 11
may be coated with medication prior to implant so that such
medication would be available for immediate application to the
tissues surrounding the prosthesis. An additional embodiment
in this respect consists of incorporating medication into the
structure of the outer wall of sac 11 so that the medication
could migrate through the matrix of the material constituting the
outer wall of the sac and evolve from the outer surface of the
wall to be available for application to the tissues surrounding
the prosthesis. It is contemplated that suitable medication
would be incorporated into the construction material for the
sac 11 during preparation of the construction material. The
medication would be incorporated in such a fashion that the
medication would remain mobile within the matrix of the
construction material. The construction material, such as
silicone rubber, would then be formed into sacs such as sac 11
and under the conditions existing within the human body, the
medication would migrate through the matrix of the silicone
rubber wall and be available for application to surrounding
tissue from the surface of the wall. Such an application of
medication would provide a method for long term treatment of
areas of the body with appropriate medication.
It will of course be understood that the particular
embodiments of the invention here shown are by way of illustra- -
tion only, and are meant to be in no way restrictive; therefore,
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numerous changes and modifications may be made and the full
use o~ equivalents resorted to, without departing from the
spirit or scope of the invention as defined by the appended
claims.
