CA1251371A - Tissue expander and method - Google Patents
Tissue expander and methodInfo
- Publication number
- CA1251371A CA1251371A CA000493507A CA493507A CA1251371A CA 1251371 A CA1251371 A CA 1251371A CA 000493507 A CA000493507 A CA 000493507A CA 493507 A CA493507 A CA 493507A CA 1251371 A CA1251371 A CA 1251371A
- Authority
- CA
- Canada
- Prior art keywords
- cover
- tissue
- expansion portion
- chamber
- base
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title abstract description 10
- 210000001519 tissue Anatomy 0.000 claims abstract description 57
- 239000012530 fluid Substances 0.000 claims abstract description 26
- 210000004872 soft tissue Anatomy 0.000 claims abstract description 23
- 210000004304 subcutaneous tissue Anatomy 0.000 claims abstract description 10
- 206010033675 panniculitis Diseases 0.000 claims abstract description 9
- 238000002347 injection Methods 0.000 claims description 18
- 239000007924 injection Substances 0.000 claims description 18
- 238000002513 implantation Methods 0.000 claims description 6
- 229920001971 elastomer Polymers 0.000 claims description 4
- 239000000806 elastomer Substances 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 4
- 230000007423 decrease Effects 0.000 claims description 3
- 201000004384 Alopecia Diseases 0.000 abstract description 9
- 206010068168 androgenetic alopecia Diseases 0.000 abstract description 9
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 18
- 210000004761 scalp Anatomy 0.000 description 16
- 229920002379 silicone rubber Polymers 0.000 description 8
- 239000000243 solution Substances 0.000 description 5
- 230000002123 temporal effect Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 210000001217 buttock Anatomy 0.000 description 3
- 210000003128 head Anatomy 0.000 description 3
- 238000001356 surgical procedure Methods 0.000 description 3
- 210000000481 breast Anatomy 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 238000007920 subcutaneous administration Methods 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- 206010039580 Scar Diseases 0.000 description 1
- 230000002730 additional effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 210000000038 chest Anatomy 0.000 description 1
- 230000002844 continuous effect Effects 0.000 description 1
- 238000002316 cosmetic surgery Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 210000005069 ears Anatomy 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000003803 hair density Effects 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- KRTSDMXIXPKRQR-AATRIKPKSA-N monocrotophos Chemical compound CNC(=O)\C=C(/C)OP(=O)(OC)OC KRTSDMXIXPKRQR-AATRIKPKSA-N 0.000 description 1
- 210000003205 muscle Anatomy 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 238000002278 reconstructive surgery Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 229920000260 silastic Polymers 0.000 description 1
- 210000003625 skull Anatomy 0.000 description 1
- 210000005196 temporal scalp Anatomy 0.000 description 1
- 238000002054 transplantation Methods 0.000 description 1
- 230000017105 transposition Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
- A61B90/02—Devices for expanding tissue, e.g. skin tissue
Abstract
Abstract of the Disclosure A soft tissue expander device adapted to be implanted beneath a layer of skin and subcutaneous tissue and filled with fluid to differentially expand the overlying tissue including methods for differentially expanding soft tissue and treating male pattern baldness.
Description
~ 25~37~
Attorney's Case No. 337 TISSUE EXPANDER AND METHOD
This invention relates to an improved inflatable soft tissue expander device and method useful in plastic and reconstructive surgery. Expander devices are conventionally implanted beneath the skin and subcutaneous tissue and then injected with a fluid to expand the overlying tissue. The device is then drained and surgically removed and the enlarged overlying tissue is surgically severed from surrounding tissue except at one edge to form an expanded tissue flap.
The flap is applied to an adjacent recipient area larger than the area of the tissue overlying the device hefore expansion.
Conventional tissue expander devices as shown in Radovan et al patent No. 4,217,889, are Eormed from a biocompatible silicone elastomer and include a flexible non-extensible base with an overlying flexible cover bonded to the periphery oE the base to define a sealed chamber between the cover and base. The area of the cover is greater than the area of the base so that when the device is collapsed the cover is folded on top of the base. The device includes an inlet port permitting hypodermic needle injection of a s-tandard saline solution into the chamber following implantation of the device beneath the skin and subcutaneous tissue.
Injection of the fluid into the chamber forces the cover above the base thereby uniformally expanding the overlying soft tissue and forming a uniformally expanded flap for subsequent application to an adjacent recipient area.
During expansion the overqying skin and subcutaneous tissues act as an elastic membrane-and are expanded in response to the pressure exterted on them by the cover as solution is injected into the chamber. The overlying tissue expands above the entire base toward a generally domed 3~
shape independent of the shape of the base. Conven-tional bases are circular, oval and rectangular in shape. ~his type of tissue expansion forms a rounded generally uniform length -flap as measured outwardly from the a-ttached flap base.
~ he generally uniform length flap is suitable for many surgical procedures. There are other procedures, however, which require or would benefit from a non-uniform length flap. Thi3 type of flap is particularly useful when -the expanded Map is applied to a non-planar or non-uniform length recipient area. ~or example, non-uniform length flapq may be used to advan-tage to reconstruct the scalp or in forming breast mound restoration3.
~ he ability to e~pand soft tis3ue overlying an implanted e~pansion device differentially and form a differential width flap in accordance wi-th -the needs of the given surgical procedure would greatly enhance the usefulness of the expansion procedure and reduce or eliminate the need to gather and surgically fi-t an expanded flap to the requiremen-ts of a given recipient area.
The disclosed expander device and method form differentially expanded tissue flaps. Differentially expanded flaps may be formed in two steps, the first step expanding the entire soft tissue overlying the expander device base and the second step expanding a portion only of -the previously e~panded overlying tissue. ~he differentially expanded flap includes a first portion which has been expanded only during the first step and a second portion expanded by both steps, the second portion having a width greater than that of the first portion.
Specifically the inven-tion relates to a soft tissue e~pander device adapted to be implanted collapsed beneath a coft tissue layer of skin and subcutaneou3 ti3sue, the device compri3ing a flexible base and expandable cover defining a fluid impervious chamber, an injection port communica-ting with the interior of the chamber to expand -the chamber, the expandable cover being in contact with the layer of skin and subcutaneou3 tis3ue when the device is impanted, the cover including a first limited expansion por-tion expandable by initial fluid injected -through the port and into the chamber from a collapsed implan-tation position to a tau-t po3ition above the collapsed position and a second differeutial expansion portion adjacent the limited expansion portion xh/JC
3~:~
expandable by the initial injected fluid wi-th the limited expan~ion portion above the collapsed implantation posi-tion, the limited expan~ion portion including mean~ for limiting further expan~ion of ~uch portion beyond the taut po~ition by further fluid injec-ted into the chamber in addition to the initial injected fluid and -the diffenential expan~ion portion including expansion means permitting further expan~ion of ~uch portion by the further fluid whereby fluid - injected through the port and in-to a chamber of an implan-ted device fir~-t expand~ bo-th the fir~t and eecond cover portion~ together wi-th lQ the ti~sue overlying ~uch portion~ a di~tance above the ba~e and then further expand~ the ~econd cover portion together with the ti~sue overlying the second cover portion only to form a differentially expanded -ti~ue flap.
One expander device u~ed to form a differentially expanded ti~sue flap i~ eimilar to the conventional expander a~ ~hown in patent no. ~I,217,889 but iB provided wi-th an improved cover having a fir~t limited expan~ion portion ~ecured to and overlying part of the baee and a ~econd differen-tial expan~ion portion joined to the fir~t - 2a -Pg/
37~ ~
portion and joined to and overlying a second part of the base. Following implantation of the expander device b neath the skin and subcutaneous tissu~ saline solution is injected into the device through an inlet port. The port may be remote from the base and ~over as in patent No. 4,217,889 or may be provided in the relative~y inexpandable portion of the cover.
As the saline solution fills the chamber between the cover and base the cover is forced upwardly away from the base and expands the overlying tissue. Initial injection of saline solutlon uniformally expands the overlying ti~sue.
The expansion is controlled by the elastic propPrties of the overlying tissue. Both portions of the cover are raised above the base essentially uniformly until the limited expansion portion is extended and becomes taut.
Expansion to this stage is the same as in a conventional expander device with a chamber cover having uniform expansion properties.
Further injection of saline solution into the chamber expands the weak differential expansion portion of the cover without appreciably further expanding the strong limited expansion portion of the cover. Such injection continues to stretch and expand the tissue overlyiny the differential expansion portion of the cover without further expanding the tissue overlying the limited expansion portion of the cover.
In this manner, the tissue overlying the expander is d~fferen-tially expanded in two steps to; form a flap having a desired shape. Expansion devices may be specially constructed to form flaps havin~ particularly useful shapes so that a surgeon may expand overlying tissue a~ required to form a specialized ~lap meeting the requirements of the particular procedure.
Differential expander devices are particularly useful in expanding the hair bearing portions of the scalp to either side of the central bald area formed by male pattern baldness. The expanded flaps have a greater anterior than posterior width. Following differen-tial expansion the flaps ,7~
are applied to cover the central bald area. The temporal hair-bearing tissue is differentially expanded anteriorly permitting the hair-bearing flap to be applied forwardly across the top of the skull to create a desired forward hairline.
Treatment of male pattern baldness by differential expansion represents a considerable improvement over conven-tional treatment of male pattern baldness by transplantation of hair plugs, serial excision of bald scalp tissue and transposition of narrow hair-bearing flaps. ~These pxocedures are costly, long in duration and frequently unsuccessful.
Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings illustrating the invention, of which there are three sheets and six embodiments.
In the Drawings:
Figure 1 is a sectional view taken along the length of an improved soft tissue expander device according to the invention;
Figure 2 is a sectional view taken along line 2--2 of Figure l;
Figure 3 is a perspective view of a device similar to the device of Figure 1 with the interior chamber filled with a saline solution and the cover taut but without differential expanslon;
Figure 4 is a view like that oE Figure 3 showing the device with additional saline,solution injected into the chamber and the èxpandable portion of the cover expanded relative to the inexpandable portion of the cover;
Figure 5 is a sectional view illustrating a deflated expander device implanted benea-th a soft tissue skin and subcutaneous layer;
Figure 6 is a sectional view similar to that of Figure 5 showing the device filled wi-th saline solution and with the cover taut as in Figure 3;
~25~
Figure 7 is a sectional view like Figures 5 and 6 but with the cover and overlying tissue differentially expanded;
Figures 8 and 9 are sectional views taken respectively along lines 8--8 and 9--9 of Figure 7;
Figures 10, 11, 12 and 13 are views similar to the view of Figure 1 illustrating further embodiments of the invention;
Figure 14 is a top view of a pair of differential tissue expander devices useful in treating male pattern baldness; and Figure 1~ is a side view illus-trating the irnplantation of one of the expanders of Figure 14 in the treatment of male pattern baldness.
Figures 1 and 2 illustrate a device 10 for differential expansion of soft tissue including a flexible base 12 having a width indicated in Figure 2 and rounded ends as in Figures 3 and 4. Cover 14 overlies the base. The base and cover comprise a con-tinuous flexible wall defining a liquid impervious chamber 16 within the interior of the device. The base may be formed from a sheet of reinforced silicone elastomer material with the reinforcement assuring -that the base is dimensionally stable during soft tissue expansion. A reinforced base facili-tates insertion of the device into a pocket below the tissue to be expanded, helps control the width of -the cover and distributes stress to the underlying tissue. In some applica-tions -the base need not be reinforced, particularly where underlying bone supports the expander device. For example, a reinforced base is not required when the expander device is used to expand tissue overlying the hard cranium. The cover may be formed from reinforced or unreinforced silicone elastomex. Both the cover and base may be formed from Silastic brand elastomer marketed by Dow Corning Corporation of Midland, Michigan.
Figures 1 and 2 illustrate -the expansion device 10 with chamber 16 inflated until the cover 14 is taut but not dimensionally expanded. In this position the cover has a uniform transverse cross section along the length of -the base with smooth, rounded ends 18 and 20 joining the rounded 37~
ends 20 and 22 of the flat base 12. A fluid inlet port 26 is provided in cover 14 adjacent end 20 to permit hypodermic needle injection of a saline solution into the chamber 16 during the expansion procedure. If desired, the device 10 may be provided with an external inlet port 2B as shown in Figures 3 and 4 and in patent No. 4,217,889. The area of the cover 14 is greater than the area of the base. When chamber 16 is empty the cover is folded and rests on the base as shown in Figure 5.
The thickness of the cover 14 decreases from base end 22 around the exterior of the chamber to base end 20. The thickness of the cover away from the base is uniform in transverse cross section as indicated in Figure 2. Port 26 is located in a relatively thick portion of the cover.
The cover 14 may be manufactured by first creating a form having an exterior shape conforming to the interior shape of the cover as shown in Figure 1 and then dipping the form in liquid silicone elastomer in a manner to form a silicone elastomer envelope surrounding the form and having the desired tapered thickness. The form may be attached to a suitable support at an area subseguently cut out for attachment of the port 26. After dipping and drying of the elastomer to form the continuous envelope the form may be crushed and withdrawn through the support openingO The bottom 30 of the continuous envelope is suitably bonded to the non-extensible base 12 as shown. The tapered thickness of bottom 30 of the envelope forms no part of the invention.
Manufacture is completed by sec`uring a port 26 to the cover as illustrated.
Figures 3 and 4 illustrate a slightly different version of the device 10 with a tapered cover as in Figure 1 and an exterior port 28. Figure 3 illustrates the device filled with 300 cc of saline solution to make the cover taut without s-tretching either the thin differential expansion portion 32 of the cover or the relatively thick limited expansion portion 34 of the cover. Portion 32 extends from base end 22 7~
around the cover end 18 and a distance along the cover toward base end 24. Portion 34 extends from portion 32 to base end 24. The taut device has an essentially uniform cross section along the length of the base as indicated in Figure 2. See Figure 1.
Figure 4 illustrates the device of Figure 3 after an additional 300 cc of fluid has been injected into chamber 16. The additional fluid elastically expands the relatively thin differential expansion cover portion 32. This portion expands, increases in area and assumes an ;nc~reasingly bulbous shape. The shape of portion 32 becomes more nearly hemispheric as additional fluid is injected into the chamber.
The strength of the silicone elastomer cover permits consider-able expansion of the portion 32 without rupture.
Limited expansion portion 34 of the cover away from expandable portion 32 has an increased thickness and is stronger than portion 32. This portion is essentially dimensionally stable and does not expand beyond the taut position of Figure 3. The inlet port is secured to cover portion 34 to assure that the cover--port connection is not unduly stressed as additional fluid is injected into the chamber. Further, by locating the inlet port in the limited expansion portion of the cover the surface of the differential expansion cover portion is kept smooth and can freely slide relative to the overlying tissue as it and the tissue expand.
As illustrated in Figure 5, the collapsed device 10 of Figure 1 is surgically implanted in tissue pocket beneath a patient's skin and subcutaneous tissue layer 36 with base 12 paralleling and facing away from the overlying soft tissue.
The collapsed cover 14 has a greater axea than the base and is folded against the base as shown. Port 26 faces the skin. The device may be inserted into the pocket through incision 37.
Figure 6 illustrates the expander device 10 of Figure 5 after sufficient saline solution has been injected into the chamber 16 through port 26 to fill the chamber without ~ ~7~77 ~
stretching the cover. Both cover por-tions 32 and 34 are taut. The overlying layer of sof-t tissue 36 has been uniformally expanded along the length of the device. Expansion of the soft tissue 36 from the condition of Figure 5 to the condition of Figure 6 is controlled by the elastic properties of the tissue itself, independent of the properties of the unfolding cover as it assumes the position of Figures 1, 2 and 3 and becomes -taut.
Further injection of saline solution into -the chamber 16 increases the pressure exerted against -the entire cover 14~
The thick, limited expansion cover portion 34 withstands the pressure without appreciable expansion. The thinner, differen-tial expansion cover portion 32 expands in response to the increased pressure and assumes a bulbous, expanded area sha~e 38 as shown in Figures 4, 7 and 9. Shape 38 becomes more nearly spherical with injection of solution.
As the cover expands from the position of Figure 6 to that of Figure 7 the soft tissue 36 overlying cover portion 32 is stressed and expands w~th the cover. The portion of the soft tissue overlying -the portion 34 of the cover is not expanded. As a result, injection of additional fluid into the chamber expands only the soft tissue overlying one end of the device 10. The ne-t result of the expansion proceeds is that the overlying soft tissue is differentially expanded with an addi-tional benefit -that the soft tissue overlying cover end 18 is expanded beyond the base as the cover portion 32 assumes bulbous shape 38. During expansion the cover is forced against the overlying tissue layer.
Figures 8 and 9 illustrate that the cover portions 32 and 34 extend circumferentially around -the cover from edge 33 to edge 35 of -the base.
Following full expansion of device 10 as shown in Figure 7 and differential expansion of the overlying sof-t tissue 36, the surgeon withdraws the sali~ne solution from chamber 16 and removes -the device 1~ from beneath -the tissue.
The expanded tissue shown in rigures 7, 8 and 9 is severed 3~
from the surroundiny tissue 40 by incisions along edges 42, 44 and 46 while leaving the expanded tissue flap attached at edge or base 48. The flap has a length outwardly from the attached base 48 greater as measured along the tissue expanded by cover portion 32 than as measured along the tissue expanded by cover portion 34. The diEferentially expanded flap is extended in the direction of arrow 50 and applied to an adjacent recepient area in the manner and with the advantages previously described.
Figure 10 illustrates a expansion device 52 similar to device 10 except that the cover is formed of a number of discrete bonded layers of silicone elastomer so that the thickness of the cover decreases in steps along the thin, differential expansion cover portion 54 and the thick limited expansion portion 56 has a uniform four layer thickness.
These portions are secured to the periphery of base 5~ like base 12.
Expander device 52 is implanted and expanded in khe same manner as desribed in connection with device 10 to differen-tially expand an overlying layer of skin and sub~utaneous tissue.
Figure 11 illustrates an expansion device 60 similar to device 10 where -the cover includes a -thick uniform thickness silicone elastomer like portion 64 of device 60. Devices 60 and 66 are used to form differentially expanded soft tissue flaps in the same manner as described in connection with device 10.
Figure 13 illustrates device 72 similar to device 66 of Figure 12 having a reinforced limited expansion cover portion 74 and a folded large area differential expansion portion 76 which may be freely expanded to assume a bulbous shape 78 as shown in dotted lines.
Device 72 is implanted beneath the layer of skin and subcutaneous ~issue and expanded in the manner described in connection wi-th device 10. The device 72 expands in the same manner as device 10 until the saline solution within g 3~7~
the chamber 82 fully expands portion 74 and similarily expands the folded portion 76. As described in connection with device 10, expansion to this point is controlled by the elastic properties of the overlying tissue 50 that the two portions 74 and 76 expand together. Injection of further saline solution into the chamber 82 unfolds and expands por-tion 76 until it assumes the fully expanded bulbous shape 78~ thus completing the differential expansion of the overlying soft tissue. Portion 74 does not expand beyond the portion of Fi~ure 13. ~
Portion 76 may be reinforced to assure that the cover assumes a known maximum shape when expanded. Alternatively, portion 76 may be formed from elastically expandable silicone elastomer so that additional saline solution may be injected into the chamber 82 to expand portion 76 sufficiently to meet the requirements of a given procedure. Additional solution may be introduced into the chambe~s of the other ~xpander device~ for further expansion of the cover portions 32, 54, 64 and 70 if the surgeon determines the maximwm length oE ~he flap should be increased.
Figure 14 is a top plan view of two scalp expansion devices 84 and 86 used in the treatment of male pattern baldness. Devices 84 and 86 are generally similar to device 10 and include a base (not illustra-ted) and a cover including a differential expansion cover portion 88 at one end of the base and a limited expansion cover portion 90 at the other end of the b~se. An inlet port 92 is provided in each cover portion 90. Portions 8,8 and 90 and port 92 may be like the previously described por-tions and ports.
The devices 84 and 86 are symmetrical as viewed from above with each including a shallow recess 94 in the lower base edge of the device when the device is implanted beneath the scalp.
Male pat-tern baldness is treated using devices 84 and 86 by making a short vertical incision 96 through the scalp at the center of the occiput and then forming two pockets beneath the scalp and subcutaneous tissue ex-tending anteriorly to either side of the incision, past the occiput and into the temporal area above each ear. The pockets are carefully formed under the hair bearing scalp and below the typical male pattern bald area 98 ~hown in Figure 14. Right hand device 84 is then implanted in the right hand pocket with recess 94 above the ear as illustrated and left hand device 86 is similarily implanted within the pocket formed on the left hand side of the head. The surgery is then completed in the conventional manner and incision 86 i5` sutured closed.
Both devices 86 and 84 are expanded by the injection of saline solution into ports 92, thereby differentially expanding the hair-bearing scalp overlying the cover portions B8 and 90 with the result that the hair-bearing temperal scalp overlying portions 88 is expanded considerably more than the hair-bearing occiputal scalp overlying portions 90.
Following differential scalp expansion and removal of the devices 84 and 86 the uppex, anterior and posterior edges of the expanded scalp are severed from the adjacent scalp, the bald scalp area is removed and 98 the flaps are drawn around the head, joined at the center line and applied to the underlyiny tissue. The flaps are longer ~t the temporal area due to the differential expansion thereby penni-tting them to meet at the top of the head and completely restore the patient's hair. In the event the differential expansion cover portions 88 bulge forward of the adjacent base ends as shown in Figure 7 the corresponding expansion of the overlying hair-bearing-scalp may be carried anteriorly to provide a desired forward front hairline.
During expansion of the hair-bearing scalp the hair density is reduced somewhat, however, this is not noticable in practice. The surgical scars resulting from the elimination of male pattern balclness using devices 84 and 86 are located under hair or adjacent the hairline and concealed by the hair.
3~l The area of hair-bearing temporal scalp available ~or expansion is fre~uently limited. In order to make maximum use of the available temporal hair the expansion device is preferrably positioned underneath as much of the available hair as possible. Expansipn of the available temporal hair is facilitated by providing the shallow recesses 94 in the devices which enables them to be extended close to and around the ears.
Expansion devices are implanted in soEt tissue a short distance below the skin. The underlying tissue supporting the base of the device is stronger than the overlying tissue so that injection of fluid into the cavity expands the cover outwardly with resultant differential soft tissue expansion. Depending upon the strength of the underlying support the base may be retainecl flat in the initial implant position or may be bowed inwardly during expansion. The support provided by underlying tissue means it is not essential to use a reinforced base in order to achieve differential soft tissue expansion. For instance9 devices 8~ and 86 used in txeating male pattern baldness are implanted in pockets directly overlying the hard cranium so that the bases of these devices are firmly supported and injection of saline solution expands the cover portions as described even if the base is not reinforced. Likewise, an expansion device usçd to diEferentially expand a flap for breast mound reconstruction is supported by the rib cage and a device implanted in a buttock for expanding buttock tissue is supported by underlying muscle. The bases of these devices need not be dimensionally stable.
Covers of expansion devi~es according to the invention need no-t have a co:Llapsed area greater than the area o~ the base. The area of the cover may be greater, equal to or less than the area of the base so long as the cover includes a limited expansion por-tion and a differential expansion portion underlying the skin and subcutaneous tissue.
The expansion devices illustrated herein all use covers with ~ single limi-ted expansion portion and a single differ-ential expansion portion so that the overlying tissue is expanded in two corresponding areas. The invention contemplates expanders with covers having two or more limited expansion or differential expansion portions in order -to form flaps having more complicated differentially expanded shapes than illustrated. For instance, an expander may include an elongate base with a cover having a limited expansion portion adjacent one end of the base, a differential expansion portion over the middle of the base and a second limited expansion portion over the other end of the base. Injection of saline solution and expansion using such a device would form a flap with two single expanded portions to either side o~ a differ-entially expanded tissue portion. Devices having other combinations oE limited and differential expansion cover portions may be provided as required.
The differentially expanded flaps described herein are attached to the surrounding tissue and are extended and applied to adjacen-t recipient areas. It is not necessar~
that a differentially expanded flap be applied in this ~ay.
In some applications, the flap may be completely removed from the surrounding tissue and applied to a remote site.
As an example, a differentially expanded flap may be formed by expanding buttock tissue, which may be transferred to the lower leg or foot.
The bases of the disclosed devices are all Eormed of flat sheet material. Bases may~be curved or may have one or more sidewalls extending upwardly toward the cover when the device is taut, that is before differential tissue expansion.
Base sidewalls increase total tissue expansion.
While I have illustrated and described preferred embodiments of my invention, it is understood that they are capable of modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.
Attorney's Case No. 337 TISSUE EXPANDER AND METHOD
This invention relates to an improved inflatable soft tissue expander device and method useful in plastic and reconstructive surgery. Expander devices are conventionally implanted beneath the skin and subcutaneous tissue and then injected with a fluid to expand the overlying tissue. The device is then drained and surgically removed and the enlarged overlying tissue is surgically severed from surrounding tissue except at one edge to form an expanded tissue flap.
The flap is applied to an adjacent recipient area larger than the area of the tissue overlying the device hefore expansion.
Conventional tissue expander devices as shown in Radovan et al patent No. 4,217,889, are Eormed from a biocompatible silicone elastomer and include a flexible non-extensible base with an overlying flexible cover bonded to the periphery oE the base to define a sealed chamber between the cover and base. The area of the cover is greater than the area of the base so that when the device is collapsed the cover is folded on top of the base. The device includes an inlet port permitting hypodermic needle injection of a s-tandard saline solution into the chamber following implantation of the device beneath the skin and subcutaneous tissue.
Injection of the fluid into the chamber forces the cover above the base thereby uniformally expanding the overlying soft tissue and forming a uniformally expanded flap for subsequent application to an adjacent recipient area.
During expansion the overqying skin and subcutaneous tissues act as an elastic membrane-and are expanded in response to the pressure exterted on them by the cover as solution is injected into the chamber. The overlying tissue expands above the entire base toward a generally domed 3~
shape independent of the shape of the base. Conven-tional bases are circular, oval and rectangular in shape. ~his type of tissue expansion forms a rounded generally uniform length -flap as measured outwardly from the a-ttached flap base.
~ he generally uniform length flap is suitable for many surgical procedures. There are other procedures, however, which require or would benefit from a non-uniform length flap. Thi3 type of flap is particularly useful when -the expanded Map is applied to a non-planar or non-uniform length recipient area. ~or example, non-uniform length flapq may be used to advan-tage to reconstruct the scalp or in forming breast mound restoration3.
~ he ability to e~pand soft tis3ue overlying an implanted e~pansion device differentially and form a differential width flap in accordance wi-th -the needs of the given surgical procedure would greatly enhance the usefulness of the expansion procedure and reduce or eliminate the need to gather and surgically fi-t an expanded flap to the requiremen-ts of a given recipient area.
The disclosed expander device and method form differentially expanded tissue flaps. Differentially expanded flaps may be formed in two steps, the first step expanding the entire soft tissue overlying the expander device base and the second step expanding a portion only of -the previously e~panded overlying tissue. ~he differentially expanded flap includes a first portion which has been expanded only during the first step and a second portion expanded by both steps, the second portion having a width greater than that of the first portion.
Specifically the inven-tion relates to a soft tissue e~pander device adapted to be implanted collapsed beneath a coft tissue layer of skin and subcutaneou3 ti3sue, the device compri3ing a flexible base and expandable cover defining a fluid impervious chamber, an injection port communica-ting with the interior of the chamber to expand -the chamber, the expandable cover being in contact with the layer of skin and subcutaneou3 tis3ue when the device is impanted, the cover including a first limited expansion por-tion expandable by initial fluid injected -through the port and into the chamber from a collapsed implan-tation position to a tau-t po3ition above the collapsed position and a second differeutial expansion portion adjacent the limited expansion portion xh/JC
3~:~
expandable by the initial injected fluid wi-th the limited expan~ion portion above the collapsed implantation posi-tion, the limited expan~ion portion including mean~ for limiting further expan~ion of ~uch portion beyond the taut po~ition by further fluid injec-ted into the chamber in addition to the initial injected fluid and -the diffenential expan~ion portion including expansion means permitting further expan~ion of ~uch portion by the further fluid whereby fluid - injected through the port and in-to a chamber of an implan-ted device fir~-t expand~ bo-th the fir~t and eecond cover portion~ together wi-th lQ the ti~sue overlying ~uch portion~ a di~tance above the ba~e and then further expand~ the ~econd cover portion together with the ti~sue overlying the second cover portion only to form a differentially expanded -ti~ue flap.
One expander device u~ed to form a differentially expanded ti~sue flap i~ eimilar to the conventional expander a~ ~hown in patent no. ~I,217,889 but iB provided wi-th an improved cover having a fir~t limited expan~ion portion ~ecured to and overlying part of the baee and a ~econd differen-tial expan~ion portion joined to the fir~t - 2a -Pg/
37~ ~
portion and joined to and overlying a second part of the base. Following implantation of the expander device b neath the skin and subcutaneous tissu~ saline solution is injected into the device through an inlet port. The port may be remote from the base and ~over as in patent No. 4,217,889 or may be provided in the relative~y inexpandable portion of the cover.
As the saline solution fills the chamber between the cover and base the cover is forced upwardly away from the base and expands the overlying tissue. Initial injection of saline solutlon uniformally expands the overlying ti~sue.
The expansion is controlled by the elastic propPrties of the overlying tissue. Both portions of the cover are raised above the base essentially uniformly until the limited expansion portion is extended and becomes taut.
Expansion to this stage is the same as in a conventional expander device with a chamber cover having uniform expansion properties.
Further injection of saline solution into the chamber expands the weak differential expansion portion of the cover without appreciably further expanding the strong limited expansion portion of the cover. Such injection continues to stretch and expand the tissue overlyiny the differential expansion portion of the cover without further expanding the tissue overlying the limited expansion portion of the cover.
In this manner, the tissue overlying the expander is d~fferen-tially expanded in two steps to; form a flap having a desired shape. Expansion devices may be specially constructed to form flaps havin~ particularly useful shapes so that a surgeon may expand overlying tissue a~ required to form a specialized ~lap meeting the requirements of the particular procedure.
Differential expander devices are particularly useful in expanding the hair bearing portions of the scalp to either side of the central bald area formed by male pattern baldness. The expanded flaps have a greater anterior than posterior width. Following differen-tial expansion the flaps ,7~
are applied to cover the central bald area. The temporal hair-bearing tissue is differentially expanded anteriorly permitting the hair-bearing flap to be applied forwardly across the top of the skull to create a desired forward hairline.
Treatment of male pattern baldness by differential expansion represents a considerable improvement over conven-tional treatment of male pattern baldness by transplantation of hair plugs, serial excision of bald scalp tissue and transposition of narrow hair-bearing flaps. ~These pxocedures are costly, long in duration and frequently unsuccessful.
Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings illustrating the invention, of which there are three sheets and six embodiments.
In the Drawings:
Figure 1 is a sectional view taken along the length of an improved soft tissue expander device according to the invention;
Figure 2 is a sectional view taken along line 2--2 of Figure l;
Figure 3 is a perspective view of a device similar to the device of Figure 1 with the interior chamber filled with a saline solution and the cover taut but without differential expanslon;
Figure 4 is a view like that oE Figure 3 showing the device with additional saline,solution injected into the chamber and the èxpandable portion of the cover expanded relative to the inexpandable portion of the cover;
Figure 5 is a sectional view illustrating a deflated expander device implanted benea-th a soft tissue skin and subcutaneous layer;
Figure 6 is a sectional view similar to that of Figure 5 showing the device filled wi-th saline solution and with the cover taut as in Figure 3;
~25~
Figure 7 is a sectional view like Figures 5 and 6 but with the cover and overlying tissue differentially expanded;
Figures 8 and 9 are sectional views taken respectively along lines 8--8 and 9--9 of Figure 7;
Figures 10, 11, 12 and 13 are views similar to the view of Figure 1 illustrating further embodiments of the invention;
Figure 14 is a top view of a pair of differential tissue expander devices useful in treating male pattern baldness; and Figure 1~ is a side view illus-trating the irnplantation of one of the expanders of Figure 14 in the treatment of male pattern baldness.
Figures 1 and 2 illustrate a device 10 for differential expansion of soft tissue including a flexible base 12 having a width indicated in Figure 2 and rounded ends as in Figures 3 and 4. Cover 14 overlies the base. The base and cover comprise a con-tinuous flexible wall defining a liquid impervious chamber 16 within the interior of the device. The base may be formed from a sheet of reinforced silicone elastomer material with the reinforcement assuring -that the base is dimensionally stable during soft tissue expansion. A reinforced base facili-tates insertion of the device into a pocket below the tissue to be expanded, helps control the width of -the cover and distributes stress to the underlying tissue. In some applica-tions -the base need not be reinforced, particularly where underlying bone supports the expander device. For example, a reinforced base is not required when the expander device is used to expand tissue overlying the hard cranium. The cover may be formed from reinforced or unreinforced silicone elastomex. Both the cover and base may be formed from Silastic brand elastomer marketed by Dow Corning Corporation of Midland, Michigan.
Figures 1 and 2 illustrate -the expansion device 10 with chamber 16 inflated until the cover 14 is taut but not dimensionally expanded. In this position the cover has a uniform transverse cross section along the length of -the base with smooth, rounded ends 18 and 20 joining the rounded 37~
ends 20 and 22 of the flat base 12. A fluid inlet port 26 is provided in cover 14 adjacent end 20 to permit hypodermic needle injection of a saline solution into the chamber 16 during the expansion procedure. If desired, the device 10 may be provided with an external inlet port 2B as shown in Figures 3 and 4 and in patent No. 4,217,889. The area of the cover 14 is greater than the area of the base. When chamber 16 is empty the cover is folded and rests on the base as shown in Figure 5.
The thickness of the cover 14 decreases from base end 22 around the exterior of the chamber to base end 20. The thickness of the cover away from the base is uniform in transverse cross section as indicated in Figure 2. Port 26 is located in a relatively thick portion of the cover.
The cover 14 may be manufactured by first creating a form having an exterior shape conforming to the interior shape of the cover as shown in Figure 1 and then dipping the form in liquid silicone elastomer in a manner to form a silicone elastomer envelope surrounding the form and having the desired tapered thickness. The form may be attached to a suitable support at an area subseguently cut out for attachment of the port 26. After dipping and drying of the elastomer to form the continuous envelope the form may be crushed and withdrawn through the support openingO The bottom 30 of the continuous envelope is suitably bonded to the non-extensible base 12 as shown. The tapered thickness of bottom 30 of the envelope forms no part of the invention.
Manufacture is completed by sec`uring a port 26 to the cover as illustrated.
Figures 3 and 4 illustrate a slightly different version of the device 10 with a tapered cover as in Figure 1 and an exterior port 28. Figure 3 illustrates the device filled with 300 cc of saline solution to make the cover taut without s-tretching either the thin differential expansion portion 32 of the cover or the relatively thick limited expansion portion 34 of the cover. Portion 32 extends from base end 22 7~
around the cover end 18 and a distance along the cover toward base end 24. Portion 34 extends from portion 32 to base end 24. The taut device has an essentially uniform cross section along the length of the base as indicated in Figure 2. See Figure 1.
Figure 4 illustrates the device of Figure 3 after an additional 300 cc of fluid has been injected into chamber 16. The additional fluid elastically expands the relatively thin differential expansion cover portion 32. This portion expands, increases in area and assumes an ;nc~reasingly bulbous shape. The shape of portion 32 becomes more nearly hemispheric as additional fluid is injected into the chamber.
The strength of the silicone elastomer cover permits consider-able expansion of the portion 32 without rupture.
Limited expansion portion 34 of the cover away from expandable portion 32 has an increased thickness and is stronger than portion 32. This portion is essentially dimensionally stable and does not expand beyond the taut position of Figure 3. The inlet port is secured to cover portion 34 to assure that the cover--port connection is not unduly stressed as additional fluid is injected into the chamber. Further, by locating the inlet port in the limited expansion portion of the cover the surface of the differential expansion cover portion is kept smooth and can freely slide relative to the overlying tissue as it and the tissue expand.
As illustrated in Figure 5, the collapsed device 10 of Figure 1 is surgically implanted in tissue pocket beneath a patient's skin and subcutaneous tissue layer 36 with base 12 paralleling and facing away from the overlying soft tissue.
The collapsed cover 14 has a greater axea than the base and is folded against the base as shown. Port 26 faces the skin. The device may be inserted into the pocket through incision 37.
Figure 6 illustrates the expander device 10 of Figure 5 after sufficient saline solution has been injected into the chamber 16 through port 26 to fill the chamber without ~ ~7~77 ~
stretching the cover. Both cover por-tions 32 and 34 are taut. The overlying layer of sof-t tissue 36 has been uniformally expanded along the length of the device. Expansion of the soft tissue 36 from the condition of Figure 5 to the condition of Figure 6 is controlled by the elastic properties of the tissue itself, independent of the properties of the unfolding cover as it assumes the position of Figures 1, 2 and 3 and becomes -taut.
Further injection of saline solution into -the chamber 16 increases the pressure exerted against -the entire cover 14~
The thick, limited expansion cover portion 34 withstands the pressure without appreciable expansion. The thinner, differen-tial expansion cover portion 32 expands in response to the increased pressure and assumes a bulbous, expanded area sha~e 38 as shown in Figures 4, 7 and 9. Shape 38 becomes more nearly spherical with injection of solution.
As the cover expands from the position of Figure 6 to that of Figure 7 the soft tissue 36 overlying cover portion 32 is stressed and expands w~th the cover. The portion of the soft tissue overlying -the portion 34 of the cover is not expanded. As a result, injection of additional fluid into the chamber expands only the soft tissue overlying one end of the device 10. The ne-t result of the expansion proceeds is that the overlying soft tissue is differentially expanded with an addi-tional benefit -that the soft tissue overlying cover end 18 is expanded beyond the base as the cover portion 32 assumes bulbous shape 38. During expansion the cover is forced against the overlying tissue layer.
Figures 8 and 9 illustrate that the cover portions 32 and 34 extend circumferentially around -the cover from edge 33 to edge 35 of -the base.
Following full expansion of device 10 as shown in Figure 7 and differential expansion of the overlying sof-t tissue 36, the surgeon withdraws the sali~ne solution from chamber 16 and removes -the device 1~ from beneath -the tissue.
The expanded tissue shown in rigures 7, 8 and 9 is severed 3~
from the surroundiny tissue 40 by incisions along edges 42, 44 and 46 while leaving the expanded tissue flap attached at edge or base 48. The flap has a length outwardly from the attached base 48 greater as measured along the tissue expanded by cover portion 32 than as measured along the tissue expanded by cover portion 34. The diEferentially expanded flap is extended in the direction of arrow 50 and applied to an adjacent recepient area in the manner and with the advantages previously described.
Figure 10 illustrates a expansion device 52 similar to device 10 except that the cover is formed of a number of discrete bonded layers of silicone elastomer so that the thickness of the cover decreases in steps along the thin, differential expansion cover portion 54 and the thick limited expansion portion 56 has a uniform four layer thickness.
These portions are secured to the periphery of base 5~ like base 12.
Expander device 52 is implanted and expanded in khe same manner as desribed in connection with device 10 to differen-tially expand an overlying layer of skin and sub~utaneous tissue.
Figure 11 illustrates an expansion device 60 similar to device 10 where -the cover includes a -thick uniform thickness silicone elastomer like portion 64 of device 60. Devices 60 and 66 are used to form differentially expanded soft tissue flaps in the same manner as described in connection with device 10.
Figure 13 illustrates device 72 similar to device 66 of Figure 12 having a reinforced limited expansion cover portion 74 and a folded large area differential expansion portion 76 which may be freely expanded to assume a bulbous shape 78 as shown in dotted lines.
Device 72 is implanted beneath the layer of skin and subcutaneous ~issue and expanded in the manner described in connection wi-th device 10. The device 72 expands in the same manner as device 10 until the saline solution within g 3~7~
the chamber 82 fully expands portion 74 and similarily expands the folded portion 76. As described in connection with device 10, expansion to this point is controlled by the elastic properties of the overlying tissue 50 that the two portions 74 and 76 expand together. Injection of further saline solution into the chamber 82 unfolds and expands por-tion 76 until it assumes the fully expanded bulbous shape 78~ thus completing the differential expansion of the overlying soft tissue. Portion 74 does not expand beyond the portion of Fi~ure 13. ~
Portion 76 may be reinforced to assure that the cover assumes a known maximum shape when expanded. Alternatively, portion 76 may be formed from elastically expandable silicone elastomer so that additional saline solution may be injected into the chamber 82 to expand portion 76 sufficiently to meet the requirements of a given procedure. Additional solution may be introduced into the chambe~s of the other ~xpander device~ for further expansion of the cover portions 32, 54, 64 and 70 if the surgeon determines the maximwm length oE ~he flap should be increased.
Figure 14 is a top plan view of two scalp expansion devices 84 and 86 used in the treatment of male pattern baldness. Devices 84 and 86 are generally similar to device 10 and include a base (not illustra-ted) and a cover including a differential expansion cover portion 88 at one end of the base and a limited expansion cover portion 90 at the other end of the b~se. An inlet port 92 is provided in each cover portion 90. Portions 8,8 and 90 and port 92 may be like the previously described por-tions and ports.
The devices 84 and 86 are symmetrical as viewed from above with each including a shallow recess 94 in the lower base edge of the device when the device is implanted beneath the scalp.
Male pat-tern baldness is treated using devices 84 and 86 by making a short vertical incision 96 through the scalp at the center of the occiput and then forming two pockets beneath the scalp and subcutaneous tissue ex-tending anteriorly to either side of the incision, past the occiput and into the temporal area above each ear. The pockets are carefully formed under the hair bearing scalp and below the typical male pattern bald area 98 ~hown in Figure 14. Right hand device 84 is then implanted in the right hand pocket with recess 94 above the ear as illustrated and left hand device 86 is similarily implanted within the pocket formed on the left hand side of the head. The surgery is then completed in the conventional manner and incision 86 i5` sutured closed.
Both devices 86 and 84 are expanded by the injection of saline solution into ports 92, thereby differentially expanding the hair-bearing scalp overlying the cover portions B8 and 90 with the result that the hair-bearing temperal scalp overlying portions 88 is expanded considerably more than the hair-bearing occiputal scalp overlying portions 90.
Following differential scalp expansion and removal of the devices 84 and 86 the uppex, anterior and posterior edges of the expanded scalp are severed from the adjacent scalp, the bald scalp area is removed and 98 the flaps are drawn around the head, joined at the center line and applied to the underlyiny tissue. The flaps are longer ~t the temporal area due to the differential expansion thereby penni-tting them to meet at the top of the head and completely restore the patient's hair. In the event the differential expansion cover portions 88 bulge forward of the adjacent base ends as shown in Figure 7 the corresponding expansion of the overlying hair-bearing-scalp may be carried anteriorly to provide a desired forward front hairline.
During expansion of the hair-bearing scalp the hair density is reduced somewhat, however, this is not noticable in practice. The surgical scars resulting from the elimination of male pattern balclness using devices 84 and 86 are located under hair or adjacent the hairline and concealed by the hair.
3~l The area of hair-bearing temporal scalp available ~or expansion is fre~uently limited. In order to make maximum use of the available temporal hair the expansion device is preferrably positioned underneath as much of the available hair as possible. Expansipn of the available temporal hair is facilitated by providing the shallow recesses 94 in the devices which enables them to be extended close to and around the ears.
Expansion devices are implanted in soEt tissue a short distance below the skin. The underlying tissue supporting the base of the device is stronger than the overlying tissue so that injection of fluid into the cavity expands the cover outwardly with resultant differential soft tissue expansion. Depending upon the strength of the underlying support the base may be retainecl flat in the initial implant position or may be bowed inwardly during expansion. The support provided by underlying tissue means it is not essential to use a reinforced base in order to achieve differential soft tissue expansion. For instance9 devices 8~ and 86 used in txeating male pattern baldness are implanted in pockets directly overlying the hard cranium so that the bases of these devices are firmly supported and injection of saline solution expands the cover portions as described even if the base is not reinforced. Likewise, an expansion device usçd to diEferentially expand a flap for breast mound reconstruction is supported by the rib cage and a device implanted in a buttock for expanding buttock tissue is supported by underlying muscle. The bases of these devices need not be dimensionally stable.
Covers of expansion devi~es according to the invention need no-t have a co:Llapsed area greater than the area o~ the base. The area of the cover may be greater, equal to or less than the area of the base so long as the cover includes a limited expansion por-tion and a differential expansion portion underlying the skin and subcutaneous tissue.
The expansion devices illustrated herein all use covers with ~ single limi-ted expansion portion and a single differ-ential expansion portion so that the overlying tissue is expanded in two corresponding areas. The invention contemplates expanders with covers having two or more limited expansion or differential expansion portions in order -to form flaps having more complicated differentially expanded shapes than illustrated. For instance, an expander may include an elongate base with a cover having a limited expansion portion adjacent one end of the base, a differential expansion portion over the middle of the base and a second limited expansion portion over the other end of the base. Injection of saline solution and expansion using such a device would form a flap with two single expanded portions to either side o~ a differ-entially expanded tissue portion. Devices having other combinations oE limited and differential expansion cover portions may be provided as required.
The differentially expanded flaps described herein are attached to the surrounding tissue and are extended and applied to adjacen-t recipient areas. It is not necessar~
that a differentially expanded flap be applied in this ~ay.
In some applications, the flap may be completely removed from the surrounding tissue and applied to a remote site.
As an example, a differentially expanded flap may be formed by expanding buttock tissue, which may be transferred to the lower leg or foot.
The bases of the disclosed devices are all Eormed of flat sheet material. Bases may~be curved or may have one or more sidewalls extending upwardly toward the cover when the device is taut, that is before differential tissue expansion.
Base sidewalls increase total tissue expansion.
While I have illustrated and described preferred embodiments of my invention, it is understood that they are capable of modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.
Claims (17)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A soft tissue expander device adapted to be implanted collapsed beneath a soft tissue layer of skin and subcutaneous tissue, the device comprising a flexible base and an expandable cover defining a fluid impervious chamber, an injection port communicating with the interior of the chamber to expand the chamber, the expandable cover being in contact with the layer of skin and subcutaneous tissue when the device is implanted, the cover including a first limited expansion portion expandable by initial fluid injected through the port and into the chamber from a collapsed implantation position to a taut position above the collapsed position and a second differential expansion portion adjacent said limited expansion portion expandable by said initial injected fluid with the limited expansion portion above the collapsed implantation position, said limited expansion portion including means for limiting further expansion of such portion beyond said taut position by further fluid injected into the chamber in addition to the initial injected fluid and said differential expansion portion including expansion means permitting further expansion of such portion by said further fluid whereby fluid injected through the port and into the chamber of an implanted device first expands both the first and second cover portions together with the tissue overlying such portions a distance above the base and then further expands the second cover portion together with the tissue overlying the second cover portion only to form a differentially expanded tissue flap.
2. A device as in claim 1 wherein one cover portion extends substantially across the cover.
3. A device as in claim 1 wherein said limited expansion portion extends substantially across the cover.
4. A device as in claim 3 wherein the differential expansion portion is formed from an elastomer material and is bulbous in shape when such portion is fully expanded.
5. A device as in claim 1 wherein both cover portions extend substantially across the cover.
6. A device as in claim 1 wherein the flexible base is elongate when collapsed and one of the portions is located at one end thereof.
7. A device as in claim 1 wherein the cover is formed of an elastomer material.
8. A device as in claim 7 wherein the cover overlies the base when the device is collapsed.
9. A device as in claim 8 wherein the thickness of the differential expansion portion is essentially uniform.
10. A device as in claim 8 wherein the differential expansion portion is thinner than the limited expansion portion.
11. A device as in claim 10 wherein the thickness of the differential expansion portion decreases in a direction away from the limited expansion portion.
12. A device as in claim 8 wherein when the device is collapsed both portions are folded, and both portions are taut following injection of initial fluid into the chamber.
13. A device as in claim 8 wherein when the device is collapsed both portion are folded, and the limited expansion portion is taut and the differential expansion portion is folded following injection of initial fluid into the chamber.
14. A device as in claim 1 wherein the device is elongate when collapsed, one cover portion is at one end of the device and the other cover portion is at the other end of the device and both cover portions extend substantially across the cover.
15. A device as in claim 1 wherein the port is formed in the limited expansion portion of the cover.
16. A device as in claim 1 wherein the port is remote from the cover.
17. A device as in claim 1 wherein the base is dimensionally stable.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US670,623 | 1984-11-13 | ||
| US06/670,623 US4574780A (en) | 1984-11-13 | 1984-11-13 | Tissue expander and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1251371A true CA1251371A (en) | 1989-03-21 |
Family
ID=24691146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000493507A Expired CA1251371A (en) | 1984-11-13 | 1985-10-22 | Tissue expander and method |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4574780A (en) |
| EP (1) | EP0181720B1 (en) |
| JP (1) | JPS61119279A (en) |
| AU (1) | AU572361B2 (en) |
| CA (1) | CA1251371A (en) |
| DE (1) | DE3577650D1 (en) |
| ZA (1) | ZA858695B (en) |
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| US9393432B2 (en) * | 2008-10-31 | 2016-07-19 | Medtronic, Inc. | Non-hermetic direct current interconnect |
| CA2821854C (en) * | 2009-12-18 | 2018-11-06 | Airxpanders, Inc. | Tissue expanders and methods of use |
| WO2012047939A2 (en) * | 2010-10-04 | 2012-04-12 | Ind Platforms Llc | Expandable devices, rail systems, and motorized devices |
| US9351824B2 (en) | 2012-11-14 | 2016-05-31 | ImplantADJUST, LLC | Adjustable implant with self-sealing elastomeric membrane and methods of fabrication thereof |
| US10820984B2 (en) | 2012-11-14 | 2020-11-03 | ImplantADJUST, LLC | Implant with elastomeric membrane and methods of fabrication thereof |
| NZ712276A (en) | 2013-02-21 | 2018-05-25 | Airxpanders Inc | Tissue expanders, implants, and methods of use |
| JP6326044B2 (en) * | 2013-04-25 | 2018-05-16 | 学校法人 久留米大学 | Tissue expander |
| GB2517210B (en) * | 2013-08-16 | 2016-05-25 | Oxtex Ltd | Coated Tissue Expander |
| US9463087B2 (en) * | 2014-03-31 | 2016-10-11 | Mentor Worldwide Llc | Directional tissue expander |
| BR112018016211A8 (en) | 2016-02-09 | 2023-02-23 | Estab Labs Sa | TRANSPONDERS, INTEGRATED GATE SET, METHODS AND SYSTEM FOR TRANSMITTING A TRANSPONDER SPECIFIC SIGNAL |
| EP3531956A1 (en) | 2016-10-28 | 2019-09-04 | Establishment Labs S.A. | Tissue expanders, methods of manufacturing and molds thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1643289A (en) * | 1921-10-10 | 1927-09-20 | Peglay Emile Joseph | Syringe |
| US3883902A (en) * | 1972-08-16 | 1975-05-20 | Medical Eng Corp | Variable volume prosthetic assembly |
| US3852832A (en) * | 1972-10-24 | 1974-12-10 | Heyer Schulte Corp | Prosthesis with fixation means |
| US3919724A (en) * | 1974-06-07 | 1975-11-18 | Medical Eng Corp | Implantable prosthesis having a self-sealing valve |
| US3924634A (en) * | 1974-09-11 | 1975-12-09 | Kendall & Co | Safety catheter and method |
| US4217889A (en) * | 1976-09-15 | 1980-08-19 | Heyer-Schulte Corporation | Flap development device and method of progressively increasing skin area |
| US4157085A (en) * | 1978-03-24 | 1979-06-05 | Dow Corning Corporation | Surgically implantable tissue expanding device and the method of its use |
| US4190040A (en) * | 1978-07-03 | 1980-02-26 | American Hospital Supply Corporation | Resealable puncture housing for surgical implantation |
| CA1151042A (en) * | 1979-04-11 | 1983-08-02 | Dow Corning Corporation | Self-sealing injection button and method of making same |
| US4428364A (en) * | 1979-04-11 | 1984-01-31 | Dow Corning Corporation | Self-sealing injection button and method of making same |
| US4574780A (en) * | 1984-11-13 | 1986-03-11 | Manders Ernest K | Tissue expander and method |
-
1984
- 1984-11-13 US US06/670,623 patent/US4574780A/en not_active Expired - Lifetime
-
1985
- 1985-10-22 CA CA000493507A patent/CA1251371A/en not_active Expired
- 1985-10-24 EP EP85307687A patent/EP0181720B1/en not_active Expired - Lifetime
- 1985-10-24 DE DE8585307687T patent/DE3577650D1/en not_active Expired - Lifetime
- 1985-11-12 JP JP60253610A patent/JPS61119279A/en active Granted
- 1985-11-12 AU AU49818/85A patent/AU572361B2/en not_active Expired
- 1985-11-13 ZA ZA858695A patent/ZA858695B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ZA858695B (en) | 1986-08-27 |
| DE3577650D1 (en) | 1990-06-21 |
| EP0181720A2 (en) | 1986-05-21 |
| EP0181720B1 (en) | 1990-05-16 |
| EP0181720A3 (en) | 1987-05-20 |
| JPS61119279A (en) | 1986-06-06 |
| AU4981885A (en) | 1986-05-22 |
| AU572361B2 (en) | 1988-05-05 |
| US4574780A (en) | 1986-03-11 |
| JPH0569541B2 (en) | 1993-10-01 |
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