出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2013/12/09 14:38:21」(JST)
A breast implant is a prosthesis used to correct the size, form, and texture of a woman’s breast; in plastic surgery, breast implants are applied for post–mastectomy breast reconstruction; for correcting congenital defects and deformities of the chest wall; for aesthetic breast augmentation; and for creating breasts in the male-to-female transsexual patient.
There are three general types of breast implant devices, defined by their filler material: saline solution, silicone gel, and composite filler. The saline implant has an elastomer silicone shell filled with sterile saline solution; the silicone implant has an elastomer silicone shell filled with viscous silicone gel; and the alternative composition implants featured miscellaneous fillers, such as soy oil, polypropylene string, et cetera.
In surgical practice, for the reconstruction of a breast, the tissue expander device is a temporary breast prosthesis used to form and establish an implant pocket for emplacing the permanent breast implant. For the correction of male breast defects and deformities, the pectoral implant is the breast prosthesis used for the reconstruction and the aesthetic repair of a man’s chest wall. (See: gynecomastia and mastopexy)
Since the late nineteenth century, breast implants have been used to surgically augment the size (volume), modify the shape (contour), and enhance the feel (tact) of a woman’s breasts. In 1895, surgeon Vincenz Czerny effected the earliest breast implant emplacement when he used the patient's autologous adipose tissue, harvested from a benign lumbar lipoma, to repair the asymmetry of the breast from which he had removed a tumor.[1] In 1889, surgeon Robert Gersuny experimented with paraffin injections, with disastrous results. From the first half of the twentieth century, physicians used other substances as breast implant fillers — ivory, glass balls, ground rubber, ox cartilage, Terylene wool, gutta-percha, Dicora, polyethylene chips, Ivalon (polyvinyl alcohol – formaldehyde polymer sponge), a polyethylene sac with Ivalon, polyether foam sponge (Etheron), polyethylene tape (Polystan) strips wound into a ball, polyester (polyurethane foam sponge) Silastic rubber, and teflon-silicone prostheses.[2]
In the mid-twentieth century, Morton I. Berson, in 1945, and Jacques Maliniac, in 1950, each performed flap-based breast augmentations by rotating the patient’s chest wall tissue into the breast to increase its volume. Furthermore, throughout the 1950s and the 1960s, plastic surgeons used synthetic fillers — including silicone injections received by some 50,000 women, from which developed silicone granulomas and breast hardening that required treatment by mastectomy.[3] In 1961, the American plastic surgeons Thomas Cronin and Frank Gerow, and the Dow Corning Corporation, developed the first silicone breast prosthesis, filled with silicone gel; in due course, the first augmentation mammoplasty was performed in 1962 using the Cronin–Gerow Implant, prosthesis model 1963. In 1964, the French company Laboratoires Arion developed and manufactured the saline breast implant, filled with saline solution, and then introduced for use as a medical device in 1964.[4]
The saline breast implant — filled with saline solution (biological-concentration salt water 0.90% w/v of NaCl, ca. 300 mOsm/L.) — was first manufactured by the Laboratoires Arion company, in France, and was introduced for use as a prosthetic medical device in 1964. The contemporary models of saline breast implant are manufactured with thicker, room-temperature vulcanized (RTV) shells made of a silicone elastomer. The study In vitro Deflation of Pre-filled Saline Breast Implants (2006) reported that the rates of deflation (filler leakage) of the pre-filled saline breast implant made it a second-choice prosthesis for corrective breast surgery.[4] Nonetheless, in the 1990s, the saline breast implant was the prosthesis usual for breast augmentation surgery, because of the U.S. FDA’s restriction against the importation of silicone-filled breast implants.
The technical goal of saline-implant technology was a physically less invasive surgical technique for emplacing an empty breast implant device through a smaller surgical incision.[5] In surgical praxis, after having emplaced the empty breast implants to the implant pockets, the plastic surgeon then filled each device with saline solution, and, because the required insertion-incisions are short and small, the resultant incision-scars will be smaller and shorter than the surgical scars usual to the long incisions required for inserting pre-filled, silicone-gel implants.
When compared to the results achieved with a silicone-gel breast implant, the saline implant can yield acceptable results, of increased breast-size, smoother hemisphere-contour, and realistic texture; yet, it is likelier to cause cosmetic problems, such as the rippling and the wrinkling of the breast-envelope skin, accelerated lower breast pole stretch, and technical problems, such as the presence of the implant being noticeable to the eye and to the touch. The occurrence of such cosmetic problems is likelier in the case of the woman with very little breast tissue, and in the case of the woman who requires post-mastectomy breast reconstruction; thus, the silicone-gel implant is the technically superior prosthetic device for breast augmentation, and for breast reconstruction. In the case of the woman with much breast tissue, for whom sub-muscular emplacement is the recommended surgical approach, saline breast implants can produce an aesthetic result much like that afforded by silicone breast implants, albeit with greater implant palpability .[6]
As a medical device technology, there are five (5) generations of silicone breast implant, each defined by common model-manufacturing techniques.
The modern prosthetic breast was invented in 1961, by the American plastic surgeons Thomas Cronin and Frank Gerow, and manufactured by the Dow Corning Corporation; in due course, the first augmentation mammoplasty was performed in 1962. There are five generations of medical device technology for the breast implant models filled with silicone gel; each generation of breast prosthesis is defined by common model-manufacturing techniques.
The Cronin–Gerow Implant, prosthesis model 1963, was a silicone rubber envelope-sac, shaped like a teardrop, which was filled with viscous silicone-gel. To reduce the rotation of the emplaced breast implant upon the chest wall, the model 1963 prosthesis was affixed to the implant pocket with a fastener-patch, made of Dacron material (Polyethylene terephthalate), which was attached to the rear of the breast implant shell.[7]
In the 1970s, manufacturers presented the second generation of breast implant prostheses that featured functional developments and aesthetic improvements to the technology:
In the 1980s, the models of the Third and of the Fourth generations of breast implant devices were sequential advances in manufacturing technology, such as elastomer-coated shells that decreased gel-bleed (filler leakage), and a thicker (increased-cohesion) filler gel. Sociologically, the manufacturers of prosthetic breasts then designed and made anatomic models (natural breast) and shaped models (round, tapered) that realistically corresponded with the breast- and body- types of women. The tapered models of breast implant have a uniformly textured surface, which reduces the rotation of the prosthesis within the implant pocket; the round models of breast implant are available in smooth-surface- and textured-surface- types.
Since the mid-1990s, the Fifth generation of silicone-gel breast implant is made of a semi-solid gel that mostly eliminates the occurrences of filler leakage (“silicone-gel bleed”) and of the migration of the silicone filler from the implant-pocket to elsewhere in the woman’s body. The studies Experience with Anatomical Soft Cohesive Silicone gel Prosthesis in Cosmetic and Reconstructive Breast Implant Surgery (2004) and Cohesive Silicone gel Breast Implants in Aesthetic and Reconstructive Breast Surgery (2005) reported low incidence-rates of capsular contracture and of device-shell rupture; and greater rates of improved medical-safety and technical-efficacy than that of early generation breast implant devices.[10][11][12]
The breast augmentation patient usually is a young woman whose personality profile indicates psychological distress about her personal appearance and her bodily self image, and a history of having endured criticism (teasing) about the aesthetics of her person.[13] The studies Body Image Concerns of Breast Augmentation Patients (2003) and Body Dysmorphic Disorder and Cosmetic Surgery (2006) reported that the woman who underwent breast augmentation surgery also had undergone psychotherapy, suffered low self-esteem, presented frequent occurrences of psychological depression, had attempted suicide, and suffered body dysmorphia, a type of mental illness.
Post-operative patient surveys about mental health and quality-of-life, reported improved physical health, physical appearance, social life, self-confidence, self-esteem, and satisfactory sexual functioning. Furthermore, the women reported long-term satisfaction with their breast implant outcomes; some despite having suffered medical complications that required surgical revision, either corrective or aesthetic. Likewise, in Denmark, 8.0 per cent of breast augmentation patients had a pre-operative history of psychiatric hospitalization.[14][15][16][17][18][19][20][21][22]
In 2008, the longitudinal study Excess Mortality from Suicide and other External Causes of Death Among Women with Cosmetic Breast Implants (2007), reported that women who sought breast implants are almost 3.0 times as likely to commit suicide as are women who have not sought breast implants. Compared to the standard suicide-rate for women of the general populace, the suicide-rate for women with augmented breasts remained constant until 10-years post-implantation, yet, it increased to 4.5 times greater at the 11-year mark, and so remained until the 19-year mark, when it increased to 6.0 times greater at 20-years post-implantation. Moreover, additional to the suicide-risk, women with breast implants also faced a trebled death-risk from alcoholism and the abuse of prescription and recreational drugs.[23][24] Although seven studies have statistically connected a woman’s breast augmentation to a greater suicide-rate, the research indicates that breast augmenation surgery does not increase the death rate; and that, in the first instance, it is the psychopathologically-inclined woman who is likelier to undergo a breast augmentation procedure.[25][26][27][28][29][30]
The study Effect of Breast Augmentation Mammoplasty on Self-Esteem and Sexuality: A Quantitative Analysis (2007), reported that the women attributed their improved self image, self-esteem, and increased, satisfactory sexual functioning to having undergone breast augmentation; the cohort, aged 21–57 years, averaged post-operative self-esteem increases that ranged from 20.7 to 24.9 points on the 30-point Rosenberg self-esteem scale, which data supported the 78.6 per cent increase in the woman’s libido, relative to her pre-operative level of libido.[31] Therefore, before agreeing to any surgery, the plastic surgeon evaluates and considers the woman’s mental health to determine if breast implants can positively affect her self-esteem and sexual functioning.
A mammoplasty procedure for the emplacement of breast implant devices has three (3) purposes:
The operating room (OR) time of post–mastectomy breast reconstruction, and of breast augmentation surgery is determined by the procedure employed, the type of incisions, the breast implant (type and materials), and the pectoral locale of the implant pocket.
Breast implant emplacement is performed with five (5) types of surgical incisions:
The four (4) surgical approaches to emplacing a breast implant to the implant pocket are described in anatomical relation to the pectoralis major muscle.
The surgical scars of a breast augmentation mammoplasty develop approximately at 6-weeks post-operative, and fade within months. Depending upon the daily-life physical activities required of the woman, the breast augmentation patient usually resumes her normal life at 1-week post-operative. Moreover, women whose breast implants were emplaced beneath the chest muscles (submuscular placement) usually have a longer, slightly more painful convalescence, because of the healing of the incisions to the chest muscles. Usually, she does not exercise or engage in strenuous physical activities for approximately 6 weeks. During the initial post-operative recovery, the woman is encouraged to regularly exercise (flex and move) her arm to alleviate pain and discomfort; if required, analgesic indwelling medication catheters can alleviate pain.[37][38] Moreover, significantly improved patient recovery has resulted from refined breast-device implantation techniques (submuscular, subglandular) that allow 95 per cent of women to resume their normal lives at 24-hours post-procedure, without bandages, fluid drains, pain pumps, catheters, medical support brassières, or narcotic pain medication.[39][40][41][42]
The plastic surgical emplacement of breast implant devices, either for breast reconstruction or for aesthetic purpose, presents the same health risks common to surgery, such as adverse reaction to anesthesia, hematoma (post-operative bleeding), late hematoma (post-operative bleeding after 6 months or more),[43] seroma (fluid accumulation), incision-site breakdown (wound infection). Complications specific to breast augmentation include breast pain, altered sensation, impeded breast-feeding function, visible wrinkling, asymmetry, thinning of the breast tissue, and symmastia, the “bread loafing” of the bust that interrupts the natural plane between the breasts. Specific treatments for the complications of indwelling breast implants — capsular contracture and capsular rupture — are periodic MRI monitoring and physical examinations. Furthermore, complications and re-operations related to the implantation surgery, and to tissue expanders (implant place-holders during surgery) can cause unfavorable scarring in approximately 6–7 per cent of the patients. [44][45][46] Statistically, 20 per cent of women who underwent cosmetic implantation, and 50 per cent of women who underwent breast reconstruction implantation, required their explantation at the 10-year mark.[47]
Because a breast implant is a Class III medical device of limited product-life, the principal rupture-rate factors are its age and design; Nonetheless, a breast implant device can retain its mechanical integrity for decades in a woman’s body.[48] When a saline breast implant ruptures, leaks, and empties, it quickly deflates, and thus can be readily explanted (surgically removed). The follow-up report, Natrelle Saline-filled Breast Implants: a Prospective 10-year Study (2009) indicated rupture-deflation rates of 3–5 per cent at 3-years post-implantation, and 7–10 per cent rupture-deflation rates at 10-years post-implantation.[49]
When a silicone breast implant ruptures it usually does not deflate, yet the filler gel does leak from it, which can migrate to the implant pocket; therefore, an intracapsular rupture (in-capsule leak) can become an extracapsular rupture (out-of-capsule leak), and each occurrence is resolved by explantation. Although the leaked silicone filler-gel can migrate from the chest tissues to elsewhere in the woman’s body, most clinical complications are limited to the breast and armpit areas, usually manifested as granulomas (inflammatory nodules) and axillary lymphadenopathy (enlarged lymph glands in the armpit area).[50][51][52]
The suspected mechanisms of breast implant rupture are:
Silicone implant rupture can be evaluated using magnetic resonance imaging; from the long-term MRI data for single-lumen breast implants, the European literature about second generation silicone-gel breast implants (1970s design), reported silent device-rupture rates of 8–15 per cent at 10-years post-implantation (15–30% of the patients).[54][55][56][57]
The study Safety and Effectiveness of Mentor’s MemoryGel Implants at 6 Years (2009), which was a branch study of the U.S. FDA’s core clinical trials for primary breast augmentation surgery patients, reported low device-rupture rates of 1.1 per cent at 6-years post-implantation.[58] The first series of MRI evaluations of the silicone breast implants with thick filler-gel reported a device-rupture rate of 1.0 per cent, or less, at the median 6-year device-age.[59] Statistically, the manual examination (palpation) of the woman is inadequate for accurately evaluating if a breast implant has ruptured. The study, The Diagnosis of Silicone Breast implant Rupture: Clinical Findings Compared with Findings at Magnetic Resonance Imaging (2005), reported that, in asymptomatic patients, only 30 per cent of the of ruptured breast implants is accurately palpated and detected by an experienced plastic surgeon, whereas MRI examinations accurately detected 86 per cent of breast implant ruptures.[60] Therefore, the U.S. FDA recommended scheduled MRI examinations, as silent-rupture screenings, beginning at the 3-year-mark post-implantation, and then every two years, thereafter.[44] Nonetheless, beyond the U.S., the medical establishments of other nations have not endorsed routine MRI screening, and, in its stead, proposed that such a radiologic examination be reserved for two purposes: (i) for the woman with a suspected breast implant rupture; and (ii) for the confirmation of mammographic and ultrasonic studies that indicate the presence of a ruptured breast implant.[61]
Furthermore, The Effect of Study design Biases on the Diagnostic Accuracy of Magnetic Resonance Imaging for Detecting Silicone Breast Implant Ruptures: a Meta-analysis (2011) reported that the breast-screening MRIs of asymptomatic women might overestimate the incidence of breast implant rupture.[62] In the event, the U.S. Food and Drug Administration emphasised that “breast implants are not lifetime devices. The longer a woman has silicone gel-filled breast implants, the more likely she is to experience complications.”[63]
The human body’s immune response to a surgically installed foreign object — breast implant, cardiac pacemaker, orthopedic prosthesis — is to encapsulate it with scar tissue capsules of tightly woven collagen fibers, in order to maintain the integrity of the body by isolating the foreign object, and so tolerate its presence. Capsular contracture — which should be distinguished from normal capsular tissue — occurs when the collagen-fiber capsule thickens and compresses the breast implant; it is a painful complication that might distort either the breast implant, or the breast, or both.
The cause of capsular contracture is unknown, but the common incidence factors include bacterial contamination, device-shell rupture, filler leakage, and hematoma. The surgical implantation procedures that have reduced the incidence of capsular contracture include submuscular emplacement, the use of breast implants with a textured surface (polyurethane-coated);[64][65][66] limited pre-operative handling of the implants, limited contact with the chest skin of the implant pocket before the emplacement of the breast implant, and irrigation of the recipient site with triple-antibiotic solutions.[67][68]
The correction of capsular contracture might require an open capsulotomy (surgical release) of the collagen-fiber capsule, or the removal, and possible replacement, of the breast implant. Furthermore, in treating capsular contracture, the closed capsulotomy (disruption via external manipulation) once was a common maneuver for treating hard capsules, but now is a discouraged technique, because it can rupture the breast implant. Non-surgical treatments for collagen-fiber capsules include massage, external ultrasonic therapy, leukotriene pathway inhibitors such as zafirlukast (Accolate) or montelukast (Singulair), and pulsed electromagnetic field therapy (PEMFT).[69][70][71][72]
When the woman is unsatisfied with the outcome of the augmentation mammoplasty; or when technical or medical complications occur; or because of the breast implants’ limited product life (Class III medical device, in the U.S.), it is likely she might require replacing the breast implants. The common revision surgery indications include major and minor medical complications, capsular contracture, shell rupture, and device deflation.[53] Revision incidence rates were greater for breast reconstruction patients, because of the post-mastectomy changes to the soft-tissues and to the skin envelope of the breast, and to the anatomical borders of the breast, especially in women who received adjuvant external radiation therapy.[53] Moreover, besides breast reconstruction, breast cancer patients usually undergo revision surgery of the nipple-areola complex (NAC), and symmetry procedures upon the opposite breast, to create a bust of natural appearance, size, form, and feel. Carefully matching the type and size of the breast implants to the patient’s pectoral soft-tissue characteristics reduces the incidence of revision surgery. Appropriate tissue matching, implant selection, and proper implantation technique, the re-operation rate was 3.0 per cent at the 7-year-mark, compared with the re-operation rate of 20 per cent at the 3-year-mark, as reported by the U.S. Food and Drug Administration.[73][74]
Some women with breast implants have reported connective tissue diseases such as systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and fibromyalgia, though any claims of association with implants have been refuted by medical research.[75] [76][77]
Platinum is used in the production of silicone gel for breast implants and small amounts may leach into surrounding tissues. However, there is no reliable medical evidence that this poses a significant health risk.[78]
The breasts are apocrine glands that produce milk for the feeding of infant children; each breast has a nipple within an areola (nipple-areola complex, NAC), the skin color of which varies from pink to dark brown, and has sebaceous glands. Within the mammary gland, the lactiferous ducts produce breast milk, and are distributed throughout the breast, with two-thirds of the tissue within 30-mm of the base of the nipple. In each breast, 4–18 lactiferous ducts drain to the nipple; the glands-to-fat ratio is 2:1 in lactating women, and to 1:1 in non-lactating women; besides milk glands, the breast is composed of connective tissue (collagen, elastin), adipose tissue (white fat), and the suspensory Cooper's ligaments. The peripheral nervous system innervation of the breast is by the anterior and lateral cutaneous branches of the fourth-, fifth-, and sixth intercostal nerves, while the Thoracic spinal nerve 4 (T4) innervating the dermatomic area supplies sensation to the nipple-areola complex.[79][80]
Digestive contamination and systemic toxicity are the principal infant-health concerns; the leakage of breast implant filler to the breast milk, and if the filler is dangerous to the nursing infant. Breast implant device fillers are biologically inert—saline filler is salt water, and silicone filler is indigestible—because each substance is chemically inert, and environmentally common. Moreover, proponent physicians have said there “should be no absolute contraindication to breast-feeding by women with silicone breast implants.”[81] In the early 1990s, at the beginning of the silicone breast implant sickness occurrences, small-scale, non-random studies (i.e. “patients came with complaints, which might have many sources”, not “doctors performed random tests”) indicated possible breast-feeding complications from silicone implants; yet no study reported device–disease causality.[82]
Women with breast implants may have functional breast-feeding difficulties; mammoplasty procedures that feature periareolar incisions are especially likely to cause breast-feeding difficulties. Surgery may also damage the lactiferous ducts and the nerves in the nipple-areola area.[83][84][85]
Functional breast-feeding difficulties arise if the surgeon cut the milk ducts or the major nerves innervating the breast, or if the milk glands were otherwise damaged. Milk duct and nerve damage are more common if the incisions cut tissue near the nipple. The milk glands are most likely to be affected by subglandular implants (under the gland), and by large-sized breast implants, which pinch the lactiferous ducts and impede milk flow. Small-sized breast implants, and submuscular implantation, cause fewer breast-function problems; however, it is impossible to predict whether a woman who undergoes breast augmentation will be able to successfully breast feed since some women are able to breast-fed after periareolarincisions and subglandular placement and some are not able to after augmentation using submuscular and other types of surgical incisions.[85]
The presence of radiologically opaque breast implants (either saline or silicone) might interfere with the radiographic sensitivity of the mammograph, that is, the image might not show any tumor(s) present. In which case, anEklund view mammogram is required to ascertain either the presence or the absence of a cancerous tumor, wherein the breast implant is manually displaced against the chest wall and the breast is pulled forward, so that the mammograph can visualize a greater volume of the internal tissues; Nonetheless, approximately one-third of the breast tissue remains inadequately visualized, resulting in an increased incidence of mammograms with false-negative results.[86]
The breast cancer studies Cancer in the Augmented Breast: Diagnosis and Prognosis (1993) and Breast Cancer after Augmentation Mammoplasty (2001) of women with breast implant prostheses reported no significant differences in disease-stage at the time of the diagnosis of cancer; prognoses are similar in both groups of women, with augmented patients at a lower risk for subsequent cancer recurrence or death.[87][88] Conversely, the use of implants for breast reconstruction after breast cancer mastectomy appears to have no negative effect upon the incidence of cancer-related death.[89] That patients with breast implants are more often diagnosed with palpable — but not larger — tumors indicates that equal-sized tumors might be more readily palpated in augmented patients, which might compensate for the impaired mammogram images.[66] The ready palpability of the breast-cancer tumor(s) is consequent to breast tissue thinning by compression, innately in smaller breasts a priori (because they have lesser tissue volumes), and that the implant serves as a radio-opaque base against which a cancerous tumor can be differentiated.[90]
The breast implant has no clinical bearing upon lumpectomy breast-conservation surgery for women who developed breast cancer after the implantation procedure, nor does the breast implant interfere with external beam radiation treatments (XRT); moreover, the post-treatment incidence of breast-tissue fibrosis is common, and thus a consequent increased rate of capsular contracture.[91] The study Breast Cancer Detection and Survival among Women with Cosmetic Breast Implants: Systematic Review and Meta-analysis of Observational Studies, reported a significant delay in the diagnoses of women who developed breast cancer after undergoing breast augmentation, when compared to breast cancer patients who had not undergone breast augmentation.[92] The metadata study Breast Implants following Mastectomy in Women with Early-stage Breast Cancer: Prevalence and Impact on Survival (2005) reported that breast augmentation patients were statistically likelier to die from breast cancer. Although the use of implants for breast reconstruction after breast cancer mastectomy appears to have no negative effect upon the incidence of cancer-related death, women who underwent a mastectomy procedure tend to die earlier than women who underwent a lumpectomy procedure, with like diagnoses.[89][93]
In 1988, twenty-six years after the 1962 introduction of breast implants filled with silicone gel, the U.S. Food and Drug Administration (FDA) investigated breast implant failures and the subsequent complications, and re-classified breast implant devices as Class III medical devices, and required from manufacturers the documentary data substantiating the safety and efficacy of their breast implant devices.[94] In 1992, the FDA placed silicone-gel breast implants in moratorium in the U.S., because there was “inadequate information to demonstrate that breast implants were safe and effective”. Nonetheless, medical access to silicone-gel breast implant devices continued for clinical studies of post-mastectomy breast reconstruction, the correction of congenital deformities, and the replacement of ruptured silicone-gel implants. The FDA required from the manufacturers the clinical trial data, and permitted their providing breast implants to the breast augmentation patients for the statistical studies required by the U.S. Food and Drug Administration.[94] In mid–1992, the FDA approved an adjunct study protocol for silicone-gel filled implants for breast reconstruction patients, and for revision-surgery patients. Also in 1992, the Dow Corning Corporation, a silicone products and breast implant manufacturer, announced the discontinuation of five implant-grade silicones, but would continue producing 45 other, medical-grade, silicone materials—three years later, in 1995, the Dow Corning Corporation went bankrupt when it faced 19,000 breast implant sickness lawsuits.[94]
The U.S. Food and Drug Administration established the age ranges for women seeking breast implants; for breast reconstruction, silicone-gel filled implants and saline-filled implants were approved for women of all ages; for breast augmentation, saline implants were approved for women 18 years of age and older; silicone implants were approved for women 22 years of age and older.[101] Because each breast implant device entails different medical risks, the minimum age of the patient for saline breast implants is different from the minimum age of the patient for silicone breast implants — because of the filler leakage and silent shell-rupture risks; thus, periodic MRI screening examinations are the recommended post-operative, follow-up therapy for the patient.[102] In other countries, in Europe and Oceania, the national health ministries' breast implant policies do not endorse periodic MRI screening of asymptomatic patients, but suggest palpation proper — with or without an ultrasonic screening — to be sufficient post-operative therapy for most patients.
In the early 1990s, the national health ministries of the listed countries reviewed the pertinent studies for causal links among silicone-gel breast implants and systemic and auto-immune diseases. The collective conclusion is that there is no evidence establishing a causal connection between the implantation of silicone breast implants and either type of disease. The affected women complained of systemic disease manifested as fungal, neurologic, and rheumatologic ailments. The Danish study Long-term Health Status of Danish Women with Silicone Breast Implants (2004) reported that women who had breast implants for an average of 19 years were no more likely to report an excessive number of rheumatic disease symptoms than would the women of the control group.[103] The follow-up study Mortality Rates Among Augmentation Mammoplasty Patients: An Update (2006) reported a decreased standardized mortality ratio and an increased risk of lung cancer death among breast implant patients, than among patients for other types of plastic surgery; the mortality rate differences were attributed to tobacco smoking.[104] The study Mortality Among Canadian Women with Cosmetic Breast Implants (2006), about some 25,000 women with breast implants, reported a 43 per cent lower rate of breast cancer among them than among the general populace, and a lower-than-average risk of cancer.[105]
Year | Country | Systemic Review Group | Conclusions |
---|---|---|---|
1991–93 | United Kingdom | Independent Expert Advisory Group (IEAG) | There was no evidence of an increased risk of connective-tissue disease in patients who had undergone silicone-gel breast implant emplacement, and no cause for changing either breast implant practice or policy in the U.K. |
1996 | United States | U.S. Institute of Medicine (IOM)[106] | There was “insufficient evidence for an association of silicone gel- or saline-filled breast implants with defined connective tissue disease”. |
1996 | France | Agence Nationale pour le Developpement de l’Evaluation Medicale (ANDEM) [National Agency for Medical Development and Evaluation] [107] | French original: “Nous n’avons pas observé de connectivite ni d’autre pathologie auto-immune susceptible d’être directement ou indirectement induite par la présence d’un implant mammaire en particulier en gel de silicone. . . .”
English translation: “We did not observe connective tissue diseases to be directly or indirectly associated with (in particular) silicone-gel breast implants. . . .” |
1997 | Australia | Therapeutic Devices Evaluation Committee (TDEC) | The “current, high-quality literature suggest that there is no association between breast implants and connective tissue disease-like syndromes (atypical connective tissue diseases).”[108] |
1998 | Germany | Federal Institute for Medicine and Medical Products | Reported that “silicone breast implants neither cause auto-immune diseases nor rheumatic diseases and have no disadvantageous effects on pregnancy, breast-feeding capability, or the health of children who are breast-fed. There is no scientific evidence for the existence of silicone allergy, silicone poisoning, atypical silicone diseases or a new silicone disease.”[109] |
2000 | United States | Federal court-ordered review[110] | “No evidence of an association between . . . silicone-gel-filled breast implants specifically, and any of the individual CTDs, all definite CTDs combined, or other auto-immune or rheumatic conditions.” |
2000 | European Union | European Committee on Quality Assurance & Medical Devices in Plastic Surgery (EQUAM) | “Additional medical studies have not demonstrated any association between silicone-gel filled breast implants and traditional auto-immune or connective tissue diseases, cancer, nor any other malignant disease. . . . EQUAM continues to believe that there is no scientific evidence that silicone allergy, silicone intoxication, atypical disease or a ‘new silicone disease’ exists.”[111] |
2001 | United Kingdom | UK Independent Review Group (UK-IRG) | “There is no evidence of an association with an abnormal immune response or typical or atypical connective tissue diseases or syndromes.”[112] |
2001 | United States | Court-appointed National Science Panel review[113] | The panel evaluated established and undifferentiated connective tissue diseases (CTD), and concluded there was no causal evidence between breast implants and these CTDs. |
2003 | Spain | Science and Technology Options Assessment (STOA) | The STOA report to the European Parliament Petitions Committee reported that the current scientific evidence demonstrates no solid, causal evidence linking SBI [silicone breast implants] to severe diseases, e.g. breast cancer, connective tissue diseases.[114] |
2009 | European Union | International Committee for Quality Assurance, Medical Technologies & Devices in Plastic Surgery panel (IQUAM) | The consensus statement of the Transatlantic Innovations conference (April 2009) indicated that additional medical studies demonstrated no association between silicone gel-filled breast implants and carcinoma, or any metabolic, immune, or allergic disorder.[115] |
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リンク元 | 「breast reconstruction」「乳房再建術」「豊胸術」 |
関連記事 | 「implant」「breast」 |
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