Long-term health status of Danish women with silicone breast implants

Long-term safety data are important in the evaluation of possible adverse health outcomes related to silicone breast implants. The authors evaluated long-term symptoms and conditions and medication use among 190 Danish women with cosmetic silicone breast implants compared with 186 women who had undergone breast reduction surgery and with 149 women from the general population. Breast implant and reduction surgeries were performed from 1973 to 1988 at one public hospital and one private plastic surgery clinic. Among women with breast implants, the average implantation time was 19 years, 60 percent (n = 114) had only one implantation, and 10 percent (n = 19) had undergone explantation before the time of study (1997 to 1998). The authors found no material differences in self-reported diseases or symptoms among study groups, except for breast pain, which was reported nearly three times as often by women with implants than by women with breast reduction (odds ratio, 2.8; 95 percent confidence interval, 1.4 to 5.3). Approximately 80 percent of women in each study group reported at least one symptom. No consistent differences were observed in the seroprevalences of antinuclear antibodies or other autoantibodies. Self-reported use of psychotropic drugs was higher among women with breast implants than among either control group. The authors conclude that long-term cosmetic breast implantation may cause capsular contracture and breast pain but does not appear to be associated with other symptoms, diseases, or autoimmune reactivity. The authors' finding of excess use of drugs for treatment of depression and anxiety among women with breast implants may warrant further investigation.     

Prevalence of silicone breast implant rupture among Danish women

The durability of silicone gel-filled breast implants is of concern, but there are few epidemiological studies on this issue. To date, most of the relevant findings are derived from studies of explantation, which suffer from bias by including women with symptoms or concerns about their implants. As part of a long-term magnetic resonance imaging study of the incidence of rupture, this study involved 271 women with 533 cosmetic breast implants who were randomly selected from among women who underwent cosmetic breast implantation from 1973 through 1997 at one public and three private plastic-surgery clinics in Denmark. The prevalence of rupture was determined from the first magnetic resonance screening. The images were evaluated by four independent readers, using a standardized, validated form. The outcomes under study were rupture, possible rupture, and intact implant. Ruptures were categorized as intracapsular or extracapsular. Overall, 26 percent of implants in 36 percent of the women examined were found to be ruptured, and an additional 6 percent were possibly ruptured. Of the ruptured implants, 22 percent were extracapsular. In multiple regression analyses, age of implant was significantly associated with rupture among second- and third-generation implants, with a 12-fold increased prevalence odds ratio for rupture of implants that were between 16 and 20 years of age, compared with implants between 3 and 5 years of age. Surgitek implants (Medical Engineering Corporation, Racine, Wis.) had a significantly increased prevalence odds ratio of 2.6 for rupture, compared with the reference implants. No significant association was found with the position (subglandular or submuscular) or the type of implant (single- or double-lumen). Extracapsular ruptures were significantly associated with a history of closed capsulotomy (p = 0.001). In the future, the authors plan to examine the women in their cohort with a second magnetic resonance imaging scan to establish the incidence of rupture, a parameter unknown to date in the literature, and to further characterize those factors associated with the actual risk of rupture.     

Self-reported symptoms among women after cosmetic breast implant and breast reduction surgery

A retrospective cohort study was performed in Sweden to evaluate the possibility that an individual symptom or constellation of illness symptoms related to silicone occurs in women after breast implant surgery. A random sample (n = 2500) of all women in the Swedish national implant registry who underwent breast augmentation surgery with alloplastic breast implants during the years 1965 through 1993 was compared with a sample (n = 3500) of women who underwent breast reduction surgery during the same period, frequency matched to the implant patients for age and calendar year at the time of surgery. In total, 65 percent of the breast implant patients (n = 1546) and 72 percent of the breast reduction patients (n = 2496) completed a self-administered questionnaire covering 28 rheumatologic and other symptoms and lifestyle and demographic factors. Practically all of the 28 symptoms inquired about were reported more often by women in the breast implant cohort, with 16 (57 percent) significantly more common in breast implant recipients. In contrast, few significant differences or consistent patterns were observed in the length of time since the implant and in the type (silicone or saline) or volume of the implant. Although women with breast implants report a multitude of symptoms more often than women who have breast reduction surgery, the lack of specificity and absence of dose-response relationships suggest that the excess of reported symptoms is not causally related to cosmetic implants.     

Local complications and subsequent symptom reporting among women with cosmetic breast implants

Epidemiologic studies have found no association between breast implants and cancer or well-defined connective tissue diseases. However, women with cosmetic breast implants continue to report specific as well as nonspecific physical and psychological symptoms after receiving their implants. In an attempt to determine whether local complications of implantation may contribute to this excess of symptom reporting, the authors studied a large cohort of women in Sweden with cosmetic breast implants (n = 1280) and a comparison cohort of women who had cosmetic breast reduction surgery (n = 2211). Both groups of women had operations between 1969 and 1996. Medical record reviews of local complications revealed that approximately 31 percent of the women with cosmetic breast implants had an implant change, implant leakage, or a capsulotomy. Capsulotomies occurred more often in women who were age 35 or older at the time of the operation, had ever smoked, and had implants with a smooth surface. On self-administered questionnaires, symptoms were reported more often by the women who had implants regardless of whether they had local complications. Twenty of the 28 symptoms occurred more frequently among women with local complications and breast implants, compared with the women in the breast reduction comparison group or the women with breast implants but no local complications. This study suggests that local complications, particularly capsular contractures as indicated by capsulotomy, may be an important factor to consider when studying symptom reporting among women with breast implants.     

Analysis of risk factors associated with rupture of silicone gel breast implants

Despite many recent studies on breast implant rupture, there is no general consensus on causation or incidence. Existing studies have not reported a multivariate analysis of risk factors associated with breast implant rupture. Most studies lack adequate sample size to study the effect of implant type, manufacturer, and other patient-related factors that might affect rupture. This study addresses all of these shortcomings. Patients undergoing implant removal by a single surgeon between 1990 and 1996 were examined for rupture and for 16 potential risk factors. The association between rupture and various factors was analyzed by univariate and multivariate analyses. A total of 842 patients underwent removal of 1619 implants. Increasing age of implant [p < 0.0001; adjusted odds ratio (OR), 1.20; 95% confidence interval (CI), 1.15 to 1.23], retroglandular location (p = 0.0002; OR, 1.93; CI, 1.37 to 2.71), Baker contracture grades III and IV (p = 0.005; OR, 1.52; CI, 1.14 to 2.03), and presence of local symptoms (p = 0.05; OR, 1.37; CI, 1.00 to 1.89) were associated with rupture. When different implant types were compared with smooth gel implants, after adjustment, double-lumen (p < 0.0001; OR, 0.33; CI, 0.22 to 0.50) and polyurethane-covered implants (p < 0.0002; OR, 0.33; CI, 0.20 to 0.57) had significantly lower rupture rates. When various manufacturers were compared with Dow Corning after adjusting for other factors, rupture rates were significantly lower for McGhan (p < 0.0001; OR, 0.41; CI, 0.26 to 0.65), whereas higher for Surgitek (p < 0.019; OR, 1.52; CI, 1.05 to 2.18). Significant risk factors for breast implant rupture were identified: older implants, retroglandular implant location, implant contracture, local symptoms, certain implant type, and certain manufacturer. Although the results of this study are based on a nonrandomized explant population from a single surgeon's practice, knowledge of these risk factors will permit better interpretation of future data on rupture. The knowledge will enable the medical community to better advise their breast implant population regarding durability and appropriate time for removal or replacement.     

Elevated serum silicon levels in women with silicone gel breast implants

The metatolic fate of silicone gel leaked from an intact or ruptured prosthesis is unknown. In this study, serum was blindly assayed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elemental silicon in 72 women with silicone gel breast implants and 55 control women (mean age 48 yr, both groups). Blood was drawn and processed using silicon-free materials. The mean silicon level in controls was 0.13±0.07 mg/L (range 0.06–0.35 mg/L), whereas in implant patients, the mean was significantly higher at 0.28±0.22 mg/L (range 0.06–0.87 mg/L) (P<0.01, Student'st-test with correction for unequal variances). Using the mean of the control group +2 SD as a cutoff for normal range (0.27 mg/L), 25/72 (34.7%) implant patients exceeded this value, compared with 2/55 (3.6%) controls. There was no significant correlation between past rupture of one or both implants, current rupture at the time of the blood draw, or the number of years with implants and silicon levels. The results suggest that serum silicon levels are elevated in many women with silicone gel breast implants. The chemical species involved and kinetics of this elevation remain to be determined.     

The deposition of talc in patients with silicone gel-filled breast implants.

This study was initiated to understand why talc was found in the entrance wounds and pericapsular scars of patients with silicone breast implants. Twenty-five surgical gloves made between 1977 and 1992 by a major glove manufacturer were evaluated with infrared spectroscopy. Seven gloves manufactured before early 1983 contained talc. Later manufactured gloves contained calcium carbonate instead of talc. Talc-containing gloves were submitted to independent laboratories for scanning electron microscopic examination and x-ray microanalysis to obtain finer detail. Remnants of the mold-release agent talc were found in the matrix of the patient-contact side of the glove. Wetting studies showed that silicone oil (gel bleed) immediately wet the surface of rubber glove. After donning, silicone oil was massaged between the thumb and index finger of each washed, talc-containing glove for 1 minute and then daubed from the glove to a microscopic slide. The slide was viewed with polarized light microscopy for the presence of talc crystals. Transfer of talc occurred using silicone oil, but not saline, in each talc-containing glove. Three factors were likely involved in the greater talc deposition that occurred with patients undergoing silicone gel-filled breast implantation than in patients undergoing other surgical procedures. (1) The wetting of the gloves with silicone gel bleed from implants loosened the talc in the glove matrix. (2) Hand-intensive surgical use freed the talc from the gloves. (3) Loose talc adhered to the silicone elastomer of the breast implants and was deposited with implant placement.     

Capsular contracture in silicone gel and saline-filled breast implants after reconstruction

Comparisons between results with randomly allotted silicone-gel and saline-filled prostheses in breast reconstruction after mastectomy led to the following conclusions. Neither prosthesis type is ideal. Leakage from saline-filled implants occurred in 2 of the 37 implants, with resultant deflation. Silicone prostheses had a significantly higher rate of capsular contracture [surgeon's evaluation: 54 percent capsular contracture for silicone-gel compared with 20 percent for saline-filled prostheses (p = 0.006); patients' evaluation for the same figures: 54 percent compared with 29 percent (p = 0.03)]. Other authors have shown the presence of silicone in the tissue around silicone-gel-filled silicone implants, but less or none around saline-filled silicone implants. Since the only difference between the two groups was the randomly allotted implants, we assume that the free silicone around silicone-gel-filled prostheses is the major cause of capsular contracture. Since the saline-filled implants showed a 20 percent capsular contracture rate, there could be other causes of capsular contracture in this study. For prevention of contracture, improved implant encapsulation and use of a less reactive filling substance seem to offer possibilities. Surgical technique should aim to preserve the integrity of the prosthesis.     

Analysis of silicon in human tissues with special reference to silicone breast implants

The increase, in the last two decades, in the application of silicones (polysiloxanes) and inorganic silicon compounds in medicine and the food industry, has exposed the human body to extensive contacts with these substances. Most silicone breast implants contain a gel consisting of a crosslinked silicone elastomer swollen by silicone oil (PDMS). Diffusion of PDMS through the silicone elastomer envelope and rupture of the envelope with release of the gel contents both occur clinically. The amount and distribution of silicone compounds in various tissues are key issues in the assessment of health problems connected with silicone implants. We have measured by GFAAS the Si content of tissues from normal and implant patients and the organic solvent extractable Si levels (assumed to be silicone), using careful control of sample collection and preparation. Whole blood levels were: implant patients mean 38.8 (SD 25.6) (microg/kg), controls mean 24.2 (SD 26.7) (microg/kg) in one study and subsequently 103.8 (SD 112.1) and 74.3 (SD 86.5) (microg/kg) in another study. Capsular tissue levels were: gel implants 25047 (SD 39313) (mg/kg of dry tissue), saline implants 20.0 (SD 27.3) (mg/kg of dry tissue) and controls 0.24 (SD 0.39) (mg/kg of dry tissue). Breast milk levels were: implant patients mean 58.7 (SD 33.8) (microg/kg), controls mean 51.1 (SD 31.0) (microg/kg); infant formula mean was 4.40 (mg/kg). Various precautions were undertaken to avoid Si contamination in this work, the most important being a) the use of a Class 100 laboratory for sample preparation and b) application of strict and elaborate washing procedure for specimen collection tools and laboratory plasticware. This data demonstrated that to properly interpret the importance of these numbers for human health, a larger study of "normal" levels of Si in human tissues should be undertaken and factors such as diet, water, race and geographical location should be considered.