Heat and Chemical Resistant Silicone Rubber
< face="Arial"> Useful Background Information
On the basis of the information available the < face="Arial">IRG (of the UK Department of Health) concluded that:
i. Silicone gel breast implants are not associated with any greater health risk than other surgical implants.
ii. Whilst it is recognized that there are a number of local complications such as capsularcontracture and gel bleed, the incidence of ill-health in women implanted with silicone gel breast implants is no greater than in the general population. In particular, there is no evidence of an association with an abnormal immune response or typical or atypical connective tissue diseases or syndromes.
iii. Children of implanted women are not at increased risk of connective tissue disease.
iv. The information provided to women undergoing breast implantation is often inadequate.
In the light of the conclusions drawn and at the same time bearing the mind the concerns raised by some implanted women, the IRG has made a number of recommendations covering:
i. The adequate provision of information prior to breast implantation, in order to assist women in making informed decisions about whether to proceed to implant surgery.
ii. The need for extending principles of good clinical practice and clinical audit across some areas of the private sector.
iii. Areas that require future research include the incidence of rupture and the investigation of conditions such as low-grade infection, which may account for some of the non-specific illnesses noted in some implanted women.
It is the intention that the IRG continue to meet to consider any new evidence on issues relating to breast implants or associated health concerns, setting out additional recommendations as necessary.
July 14, 1998
Implant-Related Surgery Risks
In addition to the risks of infection and bleeding present in all surgery, other risks are associated specifically with breast implants.
The adverse effects from breast implants fall into two categories. First are known risks that are clearly associated with these devices. Second are problems that have not been scientifically associated with breast implants, but have been reported by some women who have them. Scientists are conducting research to determine if an association does exist between these reported problems and breast implants.
Known Implant-Related Risks
Additional surgery is a risk for women with either silicone gel-filled or saline-filled implants. Surgery may be needed to treat a serious problem with the implant, or to remove a ruptured implant and, if desired, replace it. A recent study found that 24 percent of women with breast implants experience adverse events resulting in surgery during the first five years after implantation (silicone and saline implants were combined). The likelihood of needing additional surgery was greater for reconstruction than for augmentation. According to this study, women getting breast implants for reconstruction can expect about a 1 in 3 chance of needing a second surgery within five years; women getting breast implants for augmentation can expect about 1 in 8 chance of needing a second surgery within five years.
Breast implants are not lifetime devices and cannot be expected to last forever. Some implants deflate (or rupture) in the first few months after being implanted and some deflate after several years; yet others are intact 10 or more years after the surgery.
When silicone gel implants rupture, some women may notice decreased breast size, nodules, uneven appearance of the breasts, pain or tenderness, tingling, swelling, numbness, burning, or changes in sensation. Other women may experience a rupture and not notice any differences. Plastic surgeons usually recommend explantation if the implant has ruptured, even if the silicone is still enclosed within the scar tissue capsule, because the device is no longer working as intended. If the silicone gel is contained, however, some physicians think the decision of whether to explant should be more a matter of patient preference. If you are considering the removal of an implant and the implantation of another one, be sure to discuss the benefits and risks with your doctor.
The rate at which silicone gel-filled implants rupture is uncertain. However, using different methods for detection, published studies suggest between 5 and 51 percent of women experience rupture, an enormous range. A 1992 study by Destouet et al. analyzed the screening mammograms of 350 women with breast implants who had their implants for 1 to 27 years and had no symptoms. Mammograms may show ruptures in which the silicone has moved outside the implant. The study suggested that 5 percent of them had experienced "silent rupture" of their implants, although the mammogram readings were not confirmed by surgical removal of the implant. Robinson et al. studied 300 women who had their implants for 1 to 25 years and had their implants removed for a variety of reasons. They found visible signs of ruptures in 51 percent of the women studied. Severe silicone leakage -- silicone outside the implant without visible tears or holes -- was seen in another 20 percent. Robinson et al. also noted that the probability of rupture increases as the implant ages.
A silicone gel-filled implant may rupture but stay contained within the fibrous capsule the body has made around the implant. Silicone gel which escapes the fibrotic capsule surrounding the implant may migrate away from the breast. The free silicone may cause lumps called granulomas to form in the breast or other tissues where the silicone has migrated, such as the chest wall, armpit, arm or abdomen. Some studies indicate that silicone may escape the capsule in 10-20 percent of rupture cases. The long-term health effects of free silicone, if any, are not known.
Other Known Risks (for all Breast Implants)
Capsular contracture is a tightening of scar tissue around the implant. This can sometimes cause pain, hardening of the breast, or changes in breast appearance. Although it seems to occur to some extent in most women with breast implants, there are no reliable data on how often this happens. If these changes are severe, more surgery may be needed to correct or remove the implants.
Calcium deposits may form in surrounding tissue, and may cause pain and hardening of the scar tissue. In some cases, these deposits may need to be surgically removed.
Shifting of the implant: Sometimes an implant may shift from its original position, giving the breasts an unnatural look and possibly causing pain and discomfort. An implant may become visible at the surface of the breast as a result of the device pushing through the layers of skin. Further surgery is needed to correct this problem. Placing the implant beneath the muscle may help to minimize this problem.
Other problems with appearance could include incorrect implant size, visible scars, uneven appearance, and wrinkling of the implant.
Other potential complications include breast pain and delayed wound healing.
How many reports of adverse reactions (problems) has < face="Arial">FDA received?
From 1985 until March 3, 1997, FDA received 104,413 adverse reaction reports for silicone gel-filled breast implants. During the same time period, there have been 23,798 adverse reaction reports for saline-filled implants. (Because these figures come from all databases, there may be a few duplicate reports.) The greater number of reports for silicone implants does not necessarily mean that there are far more problems with silicone gel-filled implants. The greater number of reports may reflect that many more women have received silicone implants than saline implants.
Most of the health concerns about breast implants are related to silicone. Even if a silicone gel-filled breast implant does not rupture, small amounts of the silicone gel may migrate ("bleed" or "sweat") out of the implant into the surrounding tissue. There has been continuing concern that this escaped silicone might cause harmful effects, including connective tissue and related disorders and cancer.
Connective tissue and related disorders: These disorders of the body's < face="Arial">immune, or "defense" system are related to the connective tissues of the body (connective tissues include mucous, fibrous, fat, cartilage and bone tissues which support body structures and bind body parts together). These illnesses include autoimmune disorders such as lupus, scleroderma and rheumatoid arthritis, as well as disorders such as fibromyalgia and chronic fatigue syndrome. Some women with breast implants have experienced these disorders, as well as a variety of symptoms that could be related to the immune system. These symptoms include pain and swelling of joints; tightness, redness or swelling of the skin; swollen glands or lymph nodes; unusual or unexplained fatigue; swelling of the hands and feet; excessive hair loss; memory problems; headaches; and muscle weakness or burning. However, symptoms such as these may be present in persons without connective tissue disease, or without breast implants. So it is unclear at this time whether the signs and symptoms experienced by these women are related to their implants. In some cases, women have reported a reduction in symptoms after the implants were removed; in other cases, there was no change in symptoms after the implants were removed.
Please understand that individual cases cannot prove or disprove a connection between immune-related disorders and breast implants. First, as stated above, many of the various symptoms experienced by some women with breast implants are not specific to connective tissue disorders. Many people without these disorders experience some of these symptoms from time to time. Second, even if a woman with breast implants develops an immune-related disease such as lupus or rheumatoid arthritis, there
is no way to tell at this time whether the implants caused her particular disease. This is because these kinds of diseases occur both in people with and without implants. The key question is whether breast implants can increase the risk of developing these conditions. That is, do women with breast implants have a greater chance of getting immune-related disorders than women without implants?
Studies have shown that some women with silicone gel-filled breast implants produced antibodies to their own collagen (a connective tissue protein), but the incidence of these antibodies in the general population is currently unknown. Further, it is not known whether the presence of these antibodies means an increased risk of actually developing an immune-related disorder. So this study does not tell us whether there is a link between breast implants and immune-related disorders.
Several human studies have been completed recently, which provide substantial -- but not complete -- information about any possible link between breast implants and immune-related disorders. For example, a study of breast implants and connective tissue diseases, conducted at the Mayo Clinic, compared the medical records of 749 women with breast implants in Olmsted County, Minnesota, with a similar group of women from the same area who did not have implants. The conclusion was that there was no increased risk of defined connective tissue diseases among the implant recipients. Another study, conducted in
Australia, found no increase in scleroderma, a connective tissue disease whose possible connection to breast implants had been the source of some concern. Still another, the Nurses' Health Study, conducted at the Harvard Medical School, included 1,183 women with silicone gel-filled, saline, double lumen, polyurethane-coated and 56 "unknown" breast implants. This study found no increase in immune-related connective tissue diseases. These studies provide reassurance that the risk of developing a connective tissue disease due to a breast implant is not high. Taken together, these studies tell us that the vast majority of women will not develop defined immune-related disorders from the implants.
A 1996 study by Hennekens et al., also at the Harvard Medical School, is the largest yet to look at the past experiences of women with breast implants. Almost 400,000 women (nearly 11,000 with breast implants) completed questionnaires for the study. The study showed a small but statistically significant increase in the risk of connective tissue disease reported by women with breast implants. The study indicated that over a 10-year-period, women with breast implants were 1.24 times more likely to report having a connective tissue disease than women without breast implants. The increase in risk applies to all of the connective tissue diseases taken together; when calculated individually, the risk for each of these diseases was not statistically significant. According to the Hennekens study, less than 1 percent of women with breast implants will develop connective tissue diseases associated with the implants. Thus, like previous studies, the Hennekens study found that the substantial majority of women with breast implants do not develop typical connective tissue diseases.
The Hennekens study has certain limitations in its design. For example, self-reported disease was not confirmed by medical record as it is in most clinical studies. Also, only 1/4 of the women asked to participate returned the questionnaire. And the study considered all breast implants together, so if the risk of silicone gel-filled and saline-filled implants is different, this study would not have shown this difference. For all these reasons, the true risk may be different than that reported in the study.
None of the human studies described above can completely resolve the question of whether silicone gel-filled breast implants increase the risk of connective tissue disease or related disorders. First of all, except for the Hennekens study, none of them have been large enough to rule out the possibility that the implants could cause immune-related disorders in a small subset of women who have them. Secondly, since these studies were largely designed to find out whether women with the implants had certain well-defined immune-related diseases, they cannot exclude the possibility that some women with implants might develop other signs and symptoms related to the immune system that don't conform to "classic" disease descriptions. In other words, these studies do not resolve the question of whether the variety of symptoms some women report might be related to their implants.
Cancer: At this point there is no scientific evidence that silicone gel-filled breast implants can increase the risk of cancer in women, but we cannot completely rule out this possibility. Average follow-up time of completed studies in women has been too short to fully resolve this question.