AU683223B2 - Breast implant with radiolucent shell - Google Patents

Description

.F S OPI DATE 26/04/94 APPLN. ID 49983/93 111111IlI 11 111111fl!111liiii AOJP DATE 14/07/94 PCT NUMBER PCT/US93/07384 I11 11 11111 lhII AU9349983 INTERNATIONAL APPLICAIilUN MULiIZ Ui-NLJr-M I 1 -1-11 DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), QAPI patent (BF, Bi, CF, CG, CI, CM, GA, GN, Priority data: ML, MR, NE, SN, TD, TG).

07/952,687 29 September 1992 (29.09.92) US Published (71) Applicant: LIPOMATRIX, INCORPORATED [US/US]; With international search report.

1850 SEb8dz -rd PJ !ltC 40(U. Before the expiration of the time limi for amiending the o 13o 7/ o(7 'i7r 1 8uht-., claims and to be republished in the event of the receipt a.! (72) Inventors: KNAPP, Terry, Russell 915 Sierra 'Vista Drive,' amendments.

Redding, CA 96001 ANDREWS, Winston, A. 575 El Capitan Drive, Danville, CA 94526 (US).AM V (74)Agent: HAFERKAMP, Ricnard. Rogers, Howell z 2 Haferkamp, 7777 Bonhomme, Suite 1700, St. Louis, MO 63105 (US).

A LWAL (54) Title: BREAST IMPLANT WITH RADIOLUCENT SHELL (57) Abstract A breast implant includes a shell fashioned from one of a group of materials which exhibit radiolucency at those x-ray intensities normally encountered for mammographic procedures. The radiolucent shell may be Filled with radiolucent ill material as previously taught to thereby comprise a fully radiolucent breast implant. The radiolucent breast implant enhances the use of mammography in detecting tumors in patients; having breast implants to more effectively diagnose and treat cancer.

WO 94/07434 PCT/US93/07384 BREAST IMPLANT WITH RADIOLUCENT SHELL Background and Summary of the Invention Breast prostheses are well known in the art and generally include a shell or envelope which is filled with a fluid or gel which desirably is used to enlarge the female breast yet retain its normal appearance, movement, feel, and other cosmetic characteristics. Until recently, the predominant breast implant had been a silicone envelope filled with a silicone gel. However, recent health concerns have prompted the withdrawal of this implant from the market. These concerns generally relate to the health risks caused by migration of the silicone gel from within the shell, breakage of the shell, or other introduction of the silicone gel into the body.

The assignee of the present invention also holds certain rights under U.S. Patent No. 4,995,882, the disclosure of which is incorporated herein by reference, which discloses and claims a breast implant comprised of a silicone shell filled with a radiolucent fill material such as peanut oil, sunflower seed oil, or any other suitable fluid with the same atomic number as breast tissue, Z=5.9. As explained in greater detail therein, WO 94/07434 PCT/US93/07384 2 mammograms typically are performed by compressing a breast between two plates which flattens the breast and enables a more uniform exposure. A controlled intensity of x-rays are then passed through the breast for a carefully controlled time period to image any artifacts indicative of cancer. As is well known in the art of mammography, great care is taken to minimize the amount of x-ray energy used as studies have shown that certain levels of x-ray exposure will itself increase the risk of developing cancer. Typically, mammographies are conducted at low x-ray energy levels, such as between the range of 25-60 kVp. Hence, this prior patent discloses a useful and valuable invention of utilizing a fill material which is radiolucent using standard mammographic procedures and protocols, and perhaps more importantly, x-ray intensities.

The inventors herein are also aware of U.S. Patent No. 4,863,470 which discloses a standard breast implant comprised of a silicone shell with a silicone gel fill material. As previously mentioned herein, this breast implant construction is well known in the prior art and, up until recently, had been the most popular implant used. In addition, this patent discloses an identification marker or tab which is made from silicone with bismuth trioxide or barium sulfate, both of which are much more "radiopaque" than the silicone used for the standard shell or fill material. Hence, presuming an increased xray intensity which would render the standard silicone breast implant radiolucent, a marker or tab would remain opaque and thusly visible. This patent also describes a technique used to read this radiopaque marker which is more similar to a chest x-ray than to a mammogram. As taught therein, the patient lies on her back and the xrays are directed through her breast and chest cavity.

For chest x-rays, energy levels at 125 kVp are common.

The intensity of x-rays required for this procedure sub- 3 stantially exceeds that carefully controlled and timed dosage which is used for mammographic procedures. Therefore, while this patent suggests that a standard silicone gel and silicone fill material may be radiolucent, it is in reality radiopaque for standard mammographic procedures. This deficiency with this prior art implant construction was recognized and dramatically improved upon with the breast implant with radiolucent fill disclosed and claimed in prior U.S. Patent 4,995,882.

According to a first embodiment of this invention, there is provided a radiolucent breast implant comprised of a shell, said shell enclosing a volume, said volume being filled with a filler, both said shell and filler being each made of materials which are themselves substantially radiolucent under accepted inammographic protocols and intensities.

According to a second embodiment of this invention, there is provided a radiolucent breast implant comprised of a shell, said shell enclosing a volume, said volume being filled with a fill material, characterised by an improvement comprising said shell being 15 made of a material which is itself substantially radiolucent under accepted mammographic protocols and intensities.

According to a third embodiment of this invention, there is provided a radiolucent breast implant comprised of a shell, said shell enclosing a volume, said volume being filled with a filler, both said shell and filler being made of materials having an effective atomic number of 6.0 within a range of about As an enhancement to the breast implant with silicone shell and radiolucent fill, the inventors herein have succeeded in developing a breast implant with a shell which is also radiolucent. Therefore, with this breast implant, not only is the fill material comprised of a radiolucent material, but the shell also is radiolucent itself, using the standards for judging radiolucency as explained in prior U.S. Patent 4,995,882, i.e. using standard mammographic protocols, procedures, and intensities. The material which the inventors have identified and are contemplating for use for the shell include any one or more of the Sfollowing: linear aliphatic polyether urethane; linear aliphatic polyester urethane; cyclic aliphatic polyether urethane; cyclic aliphatic polyester urethane; aromatic polyether urethane; aromatic polyester urethane; polybutylene; polypropylene; crosslinked olefinic elastomers; and styrene-ethylene/butylene-styrene block copolymers. All of these materials have an effective atomic number of 6.0 within a range of and therefore exhibit the effective atomic number of fat which is the major -component of a human breast. Thus, with the present invention, a breast implant is disck sed which includes a radiolucent shell filled with a radiolucent fill material thereby rendering the entire implant optimally radiolucent for mammographic procedures.

[N:\LIBVV]00675:TCW cMMMMM WO 94/07434 PCr/US93/7384 4 It is not believed that a drawing is required or even helpful in understanding the present invention and, hence, none is being submitted.

Detailed Description of the Preferred Embodiment The inventors' preferred embodiment for achieving a breast implant shell which is essentially radiolucent using standard mammographic procedures, protocols, and intensities. The inventors believe that materials having an effective atomic number of 6.0 within a range of satisfy this criteria. As examples thereof, the present invention includes fashioning the shell from any one of a number of materials such as: linear aliphatic polyether urethane; linear aliphatic polyester urethane; cyclic aliphatic polyether urethane; cyclic aliphatic polyester urethane; aromatic polyether urethane; aromatic polyester urethane; polybutylene; polypropylene; crosslinked olefinic elastomers; and styrene-ethylene/butylene-styrene block copolymer. It is anticipated that standard manufacturing techniques well known to those of ordinary skill in the art for producing breast implants will be similarly used with the materials of the present invention. In other words, it is not anticipated that there will be any difficulty encountered by those of ordinary skill in the art in making breast implant shells with the materials suggested herein as radiolucent.

There are various changes and modifications which may be made to the invention as would be apparent to those skilled in the art. However, these changes or modifications are included in the teaching of the disclosure, and it is intended that the invention be limited only by the scope of the claims appended hereto.

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Claims (5)

1. A radiolucent breast implant comprised of a shell, said shell enclosir, volume, said volume being filled with a filler, both said shell and filler being each made of materials which are themselves substantially radiolucent under accepted mammographic protocols and intensities.

2. The radiolucent breast implant of Claim 1 wherein said shell is a material selected from the group consisting of linear aliphatic polyether urethane; linear aliphatic polyester urethane; cyclic aliphatic polyether urethane; cyclic aliphatic polyester urethane; aromatic polyether urethane; aromatic polyester urethane; polybutylene; polypropylene; crosslinked olefinic elastomers; and styrene-ethylene/butylene-styrene block copolymer.

3. A radiolucent breast implant comprised of a shell, said shell enclosing a volume, said volume being filled with a fill material, characterised by an improvement comprising said shell being made of a material which is itself substantially radiolucent under accepted mammographic protocols and intensities. is

4. The radiolucent shell of Claim 3 wherein said shell is a material selected from the group consisting of linear aliphatic polyether urethane; linear aliphatic polyester O urethane; cyclic aliphatic polyether urethane; cyclic aliphatic polyester urethane; aromatic o* polyether urethane; aromatic polyester urethane; polybutylene; polypropylene; crosslinked olefmic elastomers; and styrene-ethylene/butylene-styrene block copolymer. 20

5. A radiolucent breast implant comprised of a shell, said shell enclosing a volure, said volume being filled with a filler, both sa'd shell and filler being made of materials having an effective atomic number of 6.0 within a range of about Dated 27 March, 1995 o Lipomatrix Incorporated *0 Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON *a 00 1IbM1\16047*JOC 6 or(1 'R~asl ~w 4~1~RpsR INTERNATIONAL SEARCH REPORT [inrnational application No. PCT/US93/07384 A. CLASSIFICATION OF SUBJECT MATTER A61IF 2/12 US CL :623/8 According to International Patent Classification (1PC) or to both national classification and [PC BI. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbols) U.S. 623/7,8,11.12,66 Documcntation searched other than minimum documcntation to the extent that such documents arc included in the fields searched Electronic data base consulted during the international search (name of data base and, where practicable, search termns used) C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. X US, A, 4,995,882 (DESTQUET ET AL.) 26 FEBRUARY 1991 (SEE ENTIRE DOCUMENT) Further documents are listed in the continuation of Box C. [7See patent family annex. Special categories of cited documents: *Tr law docinent publshed after the international iling date or priority date and not In conflict with the applic~ttion but cited to understand the docuetdemin the general state of the art which is not considered prinzciple or theory undeslyingi the invean.=a to epart doue paiulishe en afterteitrioa igdt X. documnent of piarticular relevance; the claimed invention cannot be arler ocuentpublshe onor ft"dw nteratinalrilng ateconsidered novel or cannot be considered to involve an inventive step VL document which may throw doubts on priority claimfs) or which Is when the document is taken alone cited to establish the pblication date of another citation or other Y. doctument of particutar relevance; the ctaimed invention cannot he special reason (as specMe) considered to involve an inventive step when the document is .0 document re t rinit to an oral dlsclosmse a, exhibition or ether comibinedl with one or more other such docuiments, such combination meansbeing obvious to a person skilled in the at 1' d document published prio r to the International 1 iling date but laer than document member of the same patent family the priority date Date of the actual completion of the international search Date of mailing of the international search report 12 NOVEMBER 1993 0 8 FEB 1994 Nnme and mailing address of the ISA/US Authorized officer Comnmissioner of Patents and Tradcmarks/W Box PCT DAVID ISABELLA Washington, D.C. 20 231 Facsimile No. NOT APPLICABLE Telephone (703) 308-3060 Form PCT/ISA/210 (second sheet)(July 1992)*