U.S. patent number 3,683,424 [Application Number 05/006,994] was granted by the patent office on 1972-08-15 for surgically implantable compound breast prosthesis.
Invention is credited to William J. Pangman.
United States Patent |
3,683,424 |
Pangman |
August 15, 1972 |
SURGICALLY IMPLANTABLE COMPOUND BREAST PROSTHESIS
Abstract
A compound prosthesis for surgical implantation is provided that
has an elastic sack or envelope which is adapted to contain a foam
core and a quantity of a liquid in the cells of the core. The
envelope has a flexible tube for adding the liquid at the time of
implantation so that the size of the implant can be adjusted as
desired. The flexible tube can then be tied off and concealed in a
pocket in the outer layer of foam or sponge material.
Inventors: |
Pangman; William J. (Los
Angeles, CA) |
Family
ID: |
21723633 |
Appl.
No.: |
05/006,994 |
Filed: |
January 30, 1970 |
Current U.S.
Class: |
623/8;
128/DIG.21 |
Current CPC
Class: |
A61F
2/12 (20130101); Y10S 128/21 (20130101) |
Current International
Class: |
A61F
2/12 (20060101); A61f 001/00 (); A61f 001/24 ();
A41c 003/10 () |
Field of
Search: |
;3/36,1
;238/462,DIG.21 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Frinks; Ronald L.
Claims
I claim:
1. A surgical female breast prosthesis comprising:
a pliable, foamed plastic, open cell, porous core of normal
breast-simulating form, having a generally flat base, and an
apex;
said core having deep slits in spaced planes which are generally
longitudinally disposed relative to an axis that intersects the
central portion of the base and the apex of said core, said slits
terminating short of the apex of the core at one end and short of
the base of the core at the other; and
a fluid impervious elastomeric sac disposed closely about said
core;
said core being adapted to hold a liquid within its pores and
slits, and said pores and slits affording mobility for said liquid
within said core.
2. The prosthesis of claim 1, wherein said slits are in angularly
spaced planes which are generally radially disposed in relation to
said axis.
3. The prosthesis of claim 2, wherein at least some of the slits
extend only part way from the exterior surface of the core to said
axis.
4. The prosthesis of claim 2, wherein at least some of the slits
extend from the exterior of the core to said axis.
5. The prosthesis of claim 2, wherein at least some of the slits
extend inwardly from one location on the exterior surface of the
core to the general region of said axis, and thence therebeyond to
an opposite location on the external surface of the core.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to prostheses and more
particularly to an improved compound prosthesis which can be
implanted within the human body and is particularly adapted to
implantation in the female breast.
In the field of plastic surgery, it has now become a frequent
practice to implant a prosthesis in the area of a female breast
under any one of several conditions. In some cases, cancerous,
precancerous, or other abnormal or damaged tissue has been removed.
This creates a void where the tissue has been removed and it is
possible to insert a prosthesis through the incision to fill this
void. The prosthesis then becomes a replacement for the damaged
tissue removed and its purpose is to restore the body contour to
its original configuration. The prosthesis then furnishes support
for surrounding body tissue and organs to preserve as closely as
possible the original appearance of the body.
One of the main difficulties encountered in an operation of this
type is the proper sizing of the prosthesis in order to obtain the
desired external appearance. It is not always possible to decide in
advance exactly how much tissue will be removed, and consequently
it is difficult, if not impractical, to prepare an implant of the
proper size and shape prior to the operation. Instead, it has been
found advantageous to be able to vary the size of the prosthesis
after insertion and while the patient is still on the operating
table, since it is at this time that a determination can first be
made of the desired volume or size of the prosthesis.
Another problem with an implant of this character is the need for
providing a prosthesis having a softness and resiliency comparable
to that of the body tissue removed.
It is also desirable to use carefully selected materials for the
different components of the prosthesis, each being especially
adapted to carrying out its particular function and at the same
time being compatible with the human body.
Thus it becomes a general object of the present invention to
provide a surgical prosthesis that is capable of being changed in
size at the time of implantation, both to facilitate insertion and
to restore more accurately the desired body contours.
It is also an object of the present invention to provide a compound
prosthesis that can be filled with aqueous solution.
SUMMARY OF THE INVENTION
The above objects and advantages of the present invention are
achieved in a compound prosthesis having an inner core of a pliable
open-cell foam, an envelope surrounding the core, said envelope
comprising a thin, flexible wall of fluid-impervious, elastic
material, and means for adding a body of fluid to the core within
the envelope, the quantity of added fluid being a factor in
determining the size of the implant.
In a preferred embodiment, the envelope is made of a silicone
rubber which is elastic but impervious to fluids and permits the
use of a blood plasma substitute in the prosthesis. This fluid can
be placed inside the envelope through a flexible tube attached to
the envelope and which can be tied off and then concealed in a
pocket on the rear of the prosthesis formed by a loose flap of the
outer layer of resilient foam-type material.
BRIEF DESCRIPTION OF THE DRAWING
How the above objects and advantages of the present invention, as
well as others not specifically mentioned herein, are achieved will
be better understood by reference to the following description and
to the annexed drawings, in which:
FIG. 1 is a front and top perspective view of a compound prosthesis
embodying the present invention;
FIG. 2 is a rear elevation of the prosthesis, with a portion broken
away, and with the filler tube shown in tied position;
FIG. 3 is a vertical median section through the prosthesis, showing
the filler tube tied off and inserted in the pocket designed to
cover the tube;
FIG. 4 is a greatly enlarged fragmentary view within the area
encircled at 4 in FIG. 3, showing individual cells filled with a
liquid;
FIG. 5 is a front and side perspective of the core only of a
variational form of the invention; and
FIG. 6 is a median section on line 6--6 of FIG. 5 but rotated
90.degree..
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring now to the drawings, a prosthesis indicated generally at
10 comprises an inner core 12 of open-cell, foam-type plastic
material having numerous intercommunicating pores extending
throughout it. The shape of this core determines the basic shape of
the prosthesis. For purposes of this disclosure, the prosthesis
illustrated has a core which is particularly suitable for replacing
substantially the entire female breast; but it is to be understood
that this shape is illustrative only of a prosthesis for a specific
purpose and is not limitative upon the invention.
A choice of materials is available to the manufacturer for the
core. It is preferred that the core be a foamed plastic material,
for example a polyurethane or polyester, as synthetic resins of
this type are relatively inert, are pliable and resilient, can be
sterilized, and the fibers are nonabsorbent. Other suitable
materials are available. For example, a foamed polyvinyl material,
known to the trade as Ivalon, has been used for this purpose.
Surrounding core 12 is an elastic envelope 14 which acts as a
barrier membrane to retain within the envelope and core 12 any
fluid which is introduced into the envelope, such as designated at
f. Since it is desired that this envelope be elastic and also
fluid-impervious, a preferred material for this envelope is a
silicone rubber. Not only does the envelope 14 act as a barrier to
keep fluids within the envelope, but being fluid-impervious, it
excludes body fluids from the core and prevents the core from being
invaded by cellular tissue from the body.
In order that fluid may be introduced into envelope 14, it is
provided with a flexible tube 15 which is sealed to the envelope
and at that end opens to the interior of the envelope. A suitable
fluid from a source not shown in the drawing can be introduced into
the envelope and, after a suitable quantity has been introduced,
the tube can then be tied tightly as illustrated in FIGS.2 and 4,
thereby maintaining the contents of the envelope in place.
As a fluid to be placed within the envelope, it is satisfactory to
use clinical dextran which is a solution commonly used as a blood
plasma substitute. This liquid has the advantage of being readily
available, and furthermore is entirely compatible with body tissue
should the envelope break and leak for any reason at all.
The open-cell foam of core 12 absorbs the liquid added and though
the liquid moves easily within the envelope and sponge, the sponge
tends to maintain the relative contour of the prosthesis as the
wearer changes position. Thus the core gives a relatively stable
shape to the prosthesis. This is also true, even though envelope 14
is not completely filled with liquid, and if the envelope should be
ruptured the sponge sucks in and holds the liquid and thus prevents
complete collapse.
The quantity of liquid introduced can be varied, within limits, due
to the elasticity of the nature of the envelope 14. This allows the
surgeon at the time of inserting the prosthesis in the patient to
adjust the size of the implant, within limits, in order to obtain
as closely as possible the desired external body contours.
Shown here as completely surrounding envelope 14 is an outer layer
or cover 16 which is also an open-cell, foam type sponge material.
Like the core, a suitable material for this outer layer is a foam
polyester or polyurethane. Outer layer 16 is preferably
characterized by relatively small pores. The porosity of this layer
is provided in order to enable it to become invaded by body
cellular tissue, thereby causing the implant to adhere firmly to
the wall of the chest and also to the covering skin and tissue. As
a consequence, the prosthesis becomes firmly attached to the body
tissue over substantially its complete surface. This sponge
covering 16 may be optionally omitted from the front surface of the
prosthesis.
Since the prosthesis illustrated is designed to replace tissue in
the female breast, it is shaped with one side, i.e., its base,
substantially flat, this being the side that lies against the chest
wall. The same general shape is assumed by envelope 14 so that the
rear wall 14a of the envelope is likewise substantially flat. It
will be noted in FIG. 3 that filler tube 15 is attached to the
envelope at this rear wall.
Outer covering 16 has an opening 17 at the rear wall through which
filler tube 15 may extend. Around this opening layer 16 is bonded
to envelope 14, as at 16a, 16b, 16c, 16d, etc., and the outer layer
may or may not be bonded to the envelope over the remaining
portion.
Bonding outer layer 16 to the envelope around the opening therein
leaves a free portion 20 of the envelope which, like a hinged cover
or flap, can swing down to cover the opening. When filler tube 15
is tied off and folded into the area adjacent its point of entry
into the envelope, the flap 20 covers the filler tube so that the
entire external surface of the prosthesis is a layer of open-cell
foam.
It has been found advantageous to make the external layer 16
substantially uniform in thickness and relatively thin. A layer
having a thickness of the order of 1 to 2 millimeters, and
preferably not over 2 millimeters, has been found to be quite
satisfactory. A layer of this character is one that can become
thoroughly invaded by human tissue for anchoring the implant, yet
the total mass of the outer layer is sufficiently small that
shrinkage of the fibroblasts as the tissue ages and hardens has
little effect in shrinking or changing the shape of the implant.
Thus the small volume of the implant which can become invaded by
the tissue keeps shrinkage within acceptable limits.
Because the external layer is backed up by the impervious envelope
14, tissue cannot penetrate into the prosthesis beyond the external
layer. Likewise, body fluids are excluded from the prosthesis,
except in the external layer. In order to carry farther this
characteristic of limiting invasion of the prosthesis by body
tissue, the underside of flap 20 is preferably lined as at 21 with
a coating of silicone rubber or the like which renders the flap
impervious on its inner side to body tissue. This layer 21 joins or
is bonded to the envelope around the portion of the flap which
forms the hinge with the remainder of the layer 16. Thus, the
lining 21 and the opposed portion of rear wall 14a of the envelope
form a pocket to receive the tied end of filler tube 15, said
pocket being impervious to invasion by human tissue.
It has been found not necessary to sew the free edge of flap 20 to
the outer layer since the pressure of the prosthesis against the
chest wall keeps the flap in sufficiently tight contact with the
layer 16 around the lower edge of the flap to prevent infiltration
of body tissue into the pocket.
An advantage over fixed-size types of breast prostheses is that the
air can and should be completely pressed out of the device and a
clamp applied to the ingress tube before insertion beneath the
breast. The size of the skin incision may therefore be smaller than
is required for a prosthesis that is not compressed. After
insertion, dextran or other liquid may be admitted to the
prosthesis, the volume being regulated to obtain the desired size
of the prosthesis.
Variational Embodiment
An open-cell foam is characterized by intercommunication of the
pores or voids within the foam, and as a consequence the liquid
filling core 12 is ordinarily capable of some movement within or
through the core. It is obvious that this movement is facilitated
by increasing the size of the pores; but it is likewise obvious
that as the percentage of voids increases, the foam becomes softer
and more easily deformed.
In the event that it is desired to maintain the pore size
relatively small in order to increase the ability of the core to
maintain more closely its original given shape, mobility of the
liquid through the core can be increased by the construction shown
in FIGS.5 and 6. In this embodiment of the invention, the core 12a
is provided with a number of slits 30 cut into the core from the
periphery and with one or more slits or passages 31 that extend
entirely through the core. Slits 30 and passages 31 serve to limit
the maximum travel of the liquid through the body of the sponge
before reaching a slit 30 or passage 31 affording a location of
relatively free movement. They thus serve to provide a controlled
increase in the ease of movement of liquid within the core, when
this is desired. These slits or fluid passages are located in
planes which are generally longitudinal of, and preferably, in the
best form, generally radial in relation to an axis of approximate
symmetry that intersects the central portion of the base of the
core and the apex region thereof, as illustrated. The slits 30 and
31 will also be seen to terminate short of the apex of the core, so
as to leave the apex region unsevered from the base; and they also
terminate at their opposite ends short of the base, so as to avoid
severance of the base from the "segments" defined or formed by the
slits. The slits thus do not cut transversely across the core, so
as to disconnect the apex of the core from the base, and the
several "segments" of the core, thus individually intact from base
to apex, result in the slitted core retaining its "memory" through
these segments, so as to tend inherently to return to its original
form when deformed therefrom. The contained liquid flows partly via
the pores of the core material and partly via the slits 30 and 31
to move with external pressures, or relief thereof, or of change of
position, to simulate natural movement and mobility.
From the foregoing description, it will be understood that various
changes in the detailed construction of the prosthesis may occur to
persons skilled in the art without departing from the spirit and
scope of the present invention. For example, the size of shape of
the implant can be designed to fit within voids other than those
resulting from surgery on the female breast. Accordingly it is to
be understood that the foregoing description is considered as being
illustrative of rather than limitative upon the invention as
defined by the appended claims.
* * * * *