US 3189921 A
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Description (OCR text may contain errors)
Jun 2 1965 w. J. PANGMAN COMPOUND PROS'IHESIS Filed April 11; 1962 INVENTOR. Mum/11d ems/W4 vrorny United States Patent C a 3,1s9pz-1 COMPOUND PROSTHESIS William J. Pangman, 734- Muirland Vista Way, La Jioila, Calif. Filed Apr. 11, 1%2, Ser. No. 186,669 6 Claims. (CH. 3 36) This invention relates generally to prostheses and, particularly, to an improved compound prosthesis to be implanted within the human body, particularly in the female breast.
It is common practice in the field of plastic surgery to enlarge the female breast by prosthetic implants. In other cases, large portions of diseased body tissue or body organs are removed, leaving voids which may be filled by prosthetic implants. Such prosthetic implants provide physical support for the surrounding body tissue and organs and, in the case of voids near the skin, preserve the outward appearance of the body. In many instances, where cancerous, precancerous, or other abnormal or damaged tissue is removed, it is possible in insert the prosthesis to be implanted through the same surgical incision used for removing the tissue. The incision is then stitched and properly treated, making external detection of the implant extremely difficult, if not impossible.
Among the problems involved in prosthetic implants are preseving the natural softness and resiliency of the replaced body tissue and retaining the implant in position in the body. Thus, when the body tissue which is built up or replaced by a prosthetic implant is soft and resilient, the prosthesis employed is preferably also soft and resilient in order to preserve the natural body characteristics. Use of prosthesis having softness and resiliency matching as nearly as possible those of the replaced tissue is particularly important in certain areas of the body, such as the female breast, wherein the entire mammary gland, for example, may be replaced by a prosthetic implant. The importance of retaining the implant in the proper position in the body is obvious.
Up to the present invention, the requirements of softness and resiliency in a prosthetic implant have been met by the use of inert foam-type plastic sponge materials, such as that manufactured under the trade name lvalon. In addition to being soft and resilent, and thereby ideally suited to female breast implants, for example, inert sponge prostheses are porous so that they absorb blood and other body fluids and become invaded by blood vessels and living body tissues, with the result that a sponge implant and the surrounding body tissue bcome so interwoven as to permanently retain the implant in position. Over a period of time, the sponge implant actually becomes an integral part of the body structure and can be removed only by surgical procedures.
The natural porosity of inelt sponge prostheses, while beneficial for the reasons just discussed, renders the conventional one-piece sponge implant useless after a period of time. The reason for this is that blood vessels and other body cells and tissues eventually permeate the major portion of or the entire body of such an implant. The major invading tissue is fibrous tissue which shrinks as it ages, thereby causing the implant to harden and shrink.
This invention provides an improved compound prosthesis having an outer sponge shell Whose outer surface and major body portion are pervious to blood and to the ingrowth of blood vessels and fibrous tissue but whose inner surface, while pervious to body fluids, is smooth and relatively impervious to the ingrowth of cellular structure. Within a central cavity in this shell is a sponge core having a smooth outer surface which, like the inner surface of the shell, is pervious to body fluids but relatively impervious to the ingrowth of cellular structure. Ac-
Zilfifififii Patented June 22, 1965 cordingly, when the prosthesis is implanted in the body, the outer shell becomes invaded by body fluids as well as by blood vessels and surrounding fibrous body tissue, whereby the implant is permanently retained in position in the body. The relatively impervious inner surface of the shell, however, prevents a barrier against invasion of living tissue completely through the shell into the shell cavity. Accordingly, contact of such tissue with the core and the consequential irritation of the tissue by the movements of the core which occur during normal movements of the body are avoided. Moreover, the inner surface of the shell and the outer surface of the core, in contact with the inner shell surface, both being relatively impervious to the ingrowth of cellular structure of the body, prevent invasion of the core by the cellular structure and thereby minimize shrinking and hardening of the core.
An advantage of the present compound prosthesis is that in those cases where abnormal body reaction does cause undesirable shrinking or hardening of the core, the latter may be removed from the cavity within the shell and replaced with a soft new core by a simple secondary operation. If desired, the core of the present prosthetic implant may also be removed, the cavity defined by the shell enlarged by simple surgical procedure, and a new larger core inserted into the cavity for the purpose of enlarging a female breast, for example. This is a particularly important advantage in restoring the contour of the breast following radical removal of the latter because of malignant disease.
The inert sponge materials, such as Ival-on, from which the prior compound prostheses have been fabricated are deficient from the medical standpoint in that their individual fibers are absorbent and, therefore, prone to infiltration by germs. Because of this infiltration of germs directly into the sponge fibers, infections occurring in prior prosthetic implants cannot generally be cured with antibiotics or other medical treatments. As a result, most prior compound prosthetic implants which become infected must be surgically removed and replaced.
The present compound prosthesis is fabricated from an inert sponge material whose fibers are not absorbent. Accordingly, the prosthesis can be easily and completely sterilized directly in the operating suite so that the incidence of infection in prosthetic implants is substantially reduced. Generally, any infections which do occur with the present prosthetic implant can be cured by antibiotics.
A general object of this invention is, therefore, to provide an improved compound prosthesis of the character described.
A more specific object of the invention is to provide an improved compound prosthesis which, when implanted in the body, is partially invaded by blood vessels and fibrous tissues, whereby the prosthetic implant is permanently retained in the proper position, and yet which is immune to marked fibrosis and shrinking, whereby the prosthetic implant usually retains its softness and resiliency indefinitely.
Another object of the invention is to provide a compound prosthesis of the character described which is fabricated of an inert sponge material whose fibers are non-absorbent and, therefore, immune to infiltration by germs, whereby the prosthesis can be easily and com pletely sterilized in an operating room autoclave, thereby eliminating the necessity of transporting a sterile prosthesis through an unsterilized area and the attendant possibility of reinfection of the prosthesis.
An object of the invention closely related to the foregoing object is to provide a compound prosthesis of the character described in which infections occurring in the prosthesis after implanting of the latter can usually be simply cured with antibiotics.
Yet another object of the invention is to provide a compound prosthesis of the character described whose components can be premolded in any desired shape.
A further object of'the invention is to provide a compound prosthesis of the character described which is particularly useful as a female breast implant.
The invention will now be described in detail by reference to the attached drawing, wherein:
FIG. 1 is a perspective view of a female breast prosthesis constructed in accordance with the invention;
FIG. 2 is an enlarged section through the prosthesis in FIG. 1; and
FIG-3 illustrates one method of fabricating the shell of the prosthesis in FIG. 1.
The prosthesis ltl illustrated in this drawing comprises an outer hollow body or shell 12 and an inner core 14. The Wall of body or shell 12 is fabricated from an inert plastic foam sponge material whose fibers are non-absorbe-n-t, such as one of the polyurethane foam plastics. Such plastic foam sponge materials, as well known, are highly porous, containing throughout their interior a myriad of pores or openings which open through their normal exterior surfaces. The invention should not be thought of as limited to a shell made of a polyurethane foam, however, since other inert plastic sponge materials having nonabsorbent fibers may be used. It may be possible, for example, to use a polyester foam which is treated with a chemical to render its normally hard fibers sufiiciently soft for use in a prosthesis. As will be seen, core 14 is also fabricated of an inert sponge material which may be the same as that used for the shell 12.
' Shell 12 and core 14; can be conveniently fabricated by molding to the desired shape. For the particular use of the illustrated prosthesis, for example, the shell and core are molded to the natural contour shown. In actual practice, the illustrated compound prosthesis is made in several sizes and shapes to meet various natural size and shape requirements.
Shell 12 comprises a forward curved wall portion 16 and a rear, generally flat wall portion 18. These wall portions define therebetween a chamber or cavity 20 containing the core 14. Shell 12 has a smooth inner surface or skin 21 which is relatively pervious to blood and other body fluids but relatively impervious to the ingrowth of blood vessels and body tissue. The shell 12 is slit to' permit insertion of the core into the cavity. The slit 2?. for this purpose may be located at any convenient place in the shell, such as in the position shown. After insertion of the core into the shell cavity, the slit 22 is stitched, as depicted at 24.
Core 14 comprises an inner sponge body 26 and a smooth outer surface or skin 28 which, like the inner shell surface 21, is relatively pervious to blood and other body fluids but relatively impervious to the ingrowth of blood vessels and body tissue. As noted earlier, the sponge material from which the core body 26 is made may be the some inert sponge material used for the shell 12. The core body could, of course, be made of a different inert sponge material than the shell. In any event, the core body preferably comprises an inert sponge material whose fibers are nonabsorbent, whereby to prevent infiltration of germs directly into the sponge fibers. The use of sponge material having nonabsorbent fibers for both the shell and core is also advantageous since the absence of absorbed fluid in the fibers results in a lighter prosthetic implant.
The smooth, relatively impervious surfaces or skins 21 and 2% of the shell and core, respectively, may be provided in various ways. For example, the skins may comprise an impervious coating of some suitable inert material, such as a silicone, plastic or other suitable inert compound, which is sprayed on or otherwise applied to the surfaces of the shell and core. In the alternative, the surfaces or skins Z1, 28 may simply comprise the smooth,
relatively impervious surfaces which are created by contact of the foam plastic from which the shell and core are made with the smooth walls of a mold cavity.
The core 14 forms the main body of the present prosthesis, and it is the shape of the core which mainly determines the outer contour of the skin area overlying the implanted prosthesis. In other words, it is the shape of the core rather than the shape of the shell which is c-ritical. For this reason, the core is preferably made in the desired shape and the shell is shaped to fit the core. Thus, according to one method of manufacture ofthe present prosthesis, the core is molded to the desired shape in a mold cavity and a rigid form having the exact shape of the core is made. This form is placed on a fiat piece of foam plastic in the shape of the rear wall 18 of the shell 12 and which eventually forms this wall. Another fiat piece of foam plastic of the proper shape, which piece eventually forms the forward wall 16 of the shell, is then stretched over the form until the edge of the latter piece engages the edge of the first piece. These edges are then joined, as by forcing a heat sealing ring down over the form and the piece stretched thereover to press the engaging edges of the plastic pieces into intimate contact and simultanously join these edges by heat sealing them together.
The heat sealing ring used in this method of fabrication is an incomplete ring so that the edges of the pieces will be left unjoined to form the slit 22 in the shell. After heat sealing, the form is removed through this slit.
As already noted-the shell 12 has a relatively impervious inner skin or surface 21 which may comprise a suitable inert compound which is sprayed on, for example, or the skin may result from contact of the foam plastic material of the shell with a mold cavity. In this latter connection, when the shell is fabricated with the aid of the form described above, the two flat foam plastic pieces which joined to form the shell may be molded to the proper shape in flat mold cavities, or may be cut from larger sheets which are molded in mold cavities, having twice the depth of the desired wall thickness of the shell. During this molding process, contact of the foam plastic material with the wall of the mold cavities forms a smooth, relatively impervious skin on each side of the sheet or shaped piece. These sheets or pieces are then split edgewise to provide two pieces or sheets, each of the proper thickness for the shell and each having one smooth, relatively impervious surface which eventually forms the skin 21 of the shell. When the shell 12 is made by heat sealing the shell walls lid and 18 together about a form Sil as shown in FIG. 3, a smooth, impervious shell skin 21 can be formed by heating the core with a coil 32. The coil leads 34 extend through the shell slit 2'2 and the gap 36 in the heat sealing ring 33;
in use, the shell 12' and'core 1d of the prothesis are sterilized as a unit, that is, after the core has been inserted into the shell. Because the shell and core comprise a sponge material whose fibers are nonabsorbent and, therefore, immune to infiltration by germs, the shell and core can be adequately sterilized in the operating room autoclave, thereby eliminating the need of trans porting the sterile prosthesis from one place to another and the attendant possibility of reinfection of the prosthesis.
In the case of a breast implant, the incision'is usually made at the lower base portion of the breast. After removal of the gland, if this is necessary, the sterile prosthesis is compressed and inserted through the incision. Gnce located in the body cavity, the prosthesis springs back to its normal shape, pushing the patients breast or dermal layers into the original shape. If desired or necessary, additonal sponge material may be inserted between the base of the core and the rear wall of the shell after the prosthesis has been inserted into the body in order to build up the prosthesis. The slit 22 in the shell is then stitched. After any other necessary surgical pro- :3 cedures have been completed, the patients incision is stitched in the usual manner.
Over a period of time, the sponge shell 12 becomes invaded by the surrounding blood vessels and fibrous body tissues. In this Way, the prosthetic shell becomes so interwoven by the blood vessels and tissues that it becomes an integral part of the .body structure and is thereby eifectively retained in the proper position in the body. The skin 21 on the inside of the shell prevents the ingrowth of cellular structure of the body into the shell cavity Where it would contact the core and be irritated by the movements of the core which occur during normal movements of the body. Both the skin 21 on the shell and the skin 28 on the core 14; prevent invasion of cellular structure into the core body 26. Thus, the core usually retains its normal soft, resilient, flexible condition indefinitely so that a breast containing the present prosthetic implant is or can be made substantially identical to a firm normal healthy breast.
Since the fibers of the sponge material from which the prothesis is made are immune to invasion by germs, any operating room infections which do occur with the present prosthetic implant can usually be cured by the use of antibiotics. Since the sponge fibers do not absorb body fluids, the prosthetic implant also remains lighter than a prosthesis made of a sponge material with absorbent fibers.
An important advantage of the present compound prosthesis is that if the core of an implanted prosthesis becomes undesirably hard or acquires an infection which cannot be cured by medical treatment, the core can be removed from and a new core replaced in the cavity 29 within the shell 12 of the implanted prosthesis by means of a simple secondary operation. Moreover, at anytime, the core can be removed from an implanted proethesis, the cavity in the implanted shell enlarged by simple surgical procedures, and a new larger core then replaced in the shell in order to enlarge the implant. This is especially important, for example, in restoring the female breast contour following radical removal of a breast because of malignant disease.
Various modifications within the spirt and scope of the present invention will occur to those skilled in the art. While the invention has been described in connection with a breast operation, it is to be understood that compound prosthetic devices of this type may be employed as substitutes for a lung or other organs of the body with great success. The invention, therefore, is not to be thought of as limited to the specific embodiment chosen for illustrative purposes.
What is claimed is:
1. A compound surgical prosthesis for insertion under the skin of the human body, comprising:
an exterior surrounding wall,
substantially the entire interior surface of said Wall bounded by a surface layer which is integral therewith and which is relatively impervious to cellular structure of the human body but relatively pervious to fluids in the human body, and the exterior thickness of said wall outside said interior surface layer including substantially the entire exterior surface thereof being comprised of a foam-type resilient plastic surgical sponge material having a myriad of pores extending throughout it and opening through said exterior surface of the wall, whereby said exterior thickness of the Wall is relatively pervious to 6 both said cellular structure and fluids of the human body,
there being a sealed closure in said wall,
a core substantially completely filling the space inside said Wall, and
substantially the entire exterior surface of said core having a surface layer which is relatively impervious to said cellular structure of the human body but relatively pervious to said fluids in the human body, and the interior portion of said core inside said exterior surface layer being comprised of a foam-type resilient plastic surgical sponge material having a myriad of pores extending throughout it, whereby the latter is also relatively pervious to said body fluids.
2. A compound prosthesis according to claim 1 wherein:
the individual fibers of the surgical sponge material of both said body wall and core are relatively impervious to said body fluids.
3. A compound prosthesis according to claim 1 wherein:
at least one of said impervious surface layers comprises a smooth surface of the respective surgical sponge material itself wherein the sponge pores are substantially sealed.
4. A compound prosthesis according to claim 1 wherein:
at least one of said impervious surface layers comprises a thin layer of a material different from and coated directly on the respective surgical sponge material.
5. A compound prosthesis according to claim 1 wherein:
at least one of said surgical sponge materials comprises a polyurethane foam plastic.
6. A compound surgical prosthesis for insertion under the skin of the human body, comprising: an exterior surrounding wall, substantially the entire interior surface of said surrounding wall being bounded by a surface layer which is relatively impervious to cellular structure of the human body but relatively pervious to fluids in the human body, and the exterior thickness of said wall outside said interior surface layer including substantially the entire exterior surface thereof being comprised of a foam-type resilient plastic surgical sponge material having a myriad of pores extending throughout it and opening through said exterior surface of the wall, whereby said exterior thickness of the wall is relatively pervious to both said cellular structure and fluids of the human body, there being a sealed closure in said wall, a core substantially completely filling the space inside said wall, and said core being comprised of a foam-type resilient plastic surgical sponge material having a myriad of pores extending throughout its interior, whereby the core is relatively pervious to said body fluids.
References Cited by the Examiner UNITED STATES PATENTS 2,636,182 4/53 Freedman 336 2,698,436 1/55 Bernhardt 336 2,752,602 7/56 Wilhelm 3-36 2,842,775 7/58 Pangman 128-462 3,067,431 12/62 Kausch 3-36 LOUIS R. PRINCE, Primary Examiner. ADELE M. EAGER, Examiner.