Women considering breast implantation surgery often have questions for their surgeon related to the strength and durability of the implants they are considering. The most common of these questions include:
For more than 15 years, I have worked with a group at Washington University in St. Louis that has studied these questions. My conclusion from this research, as well as from my evaluation of research conducted by other scientists, is that the breast implants in use today, including silicone gel-filled breast implants, are very durable in the body. Only a very small percentage of these silicone gel-filled breast implants have been shown to break or rupture, and a large number of studies and review papers have concluded that a ruptured implant (saline and/or silicone gel-filled) has no long-term impact on a woman's health.
While the studies to date on this topic are reassuring, manufacturers and medical professionals are continuously taking steps to improve the strength and durability of breast implants, including silicone gel-filled breast implants.
Studies Assessing the Strength and Durability of Silicone Breast Implants
In 1992, a breast implant research group was established at Washington University in St. Louis as a joint effort between the schools of medicine and engineering. We formed the group to study and analyze breast implants, and particularly to answer the types of questions that are outlined above.
Before I describe the research conducted by our group and other investigators to explore breast implant durability in the body, it is important to understand what is meant by several terms relevant to breast implants.
All of the implants sold in the United States today are composed of two primary parts: an outer silicone covering, or shell, and a filler material contained within the shell, which can be either silicone gel or saline (salt water). In addition, once a breast implant has been placed in the body, the body naturally forms a tissue lining around the implant, referred to as the "fibrous capsule."
While the two primary components of breast implants have been the same since the first implants were developed in the early 1960s, the make-up of these components has changed significantly. As manufacturers have improved the strength of implant shells, the potential for rupture has decreased. The types of implants created by manufacturers over the years are known as “generations.”1
Third generation silicone gel-filled breast implants are the implants used in the United States today. These types of implants are rigorously tested and analyzed to meet the chemical and mechanical guidelines of the United States Food and Drug Administration (FDA).2
Experiments have shown that some of the components of the gel inside a silicone gel-filled breast implant – primarily silicone oil – can spread into the implant shell and, subsequently, into the surrounding fibrous capsule. This process is known as silicone "gel bleed." There are a few things that are important to note about this process. First, we are all exposed to silicone on a daily basis, through our environment and many products, including cosmetics and medicines (e.g., antacids). Silicone oil is a component of the injection needle that people with diabetes use on a daily basis.
The FDA has investigated whether there are any medical issues associated with exposure to silicones, including the process of silicone gel bleed, and determined there is no evidence of harm. In addition, a report released by the Institute of Medicine (IOM) in 1999 found the studies exploring human exposure to silicones, even at very high doses, to be reassuring.3 Therefore, while gel bleed does lead to exposure to a minute amount of silicone oil, this exposure has not been shown to be associated with disease.
Although implants have been shown to be strong and durable in the body, it is possible for an implant shell to develop a tear or hole. An opening that develops in the outer shell of an implant is known as an implant "rupture." This opening can allow the filler to escape through the shell. If the implant filler stays within the body's fibrous capsule, we call this an "intracapsular rupture." If the fibrous capsule also breaks, it is known as an "extracapsular rupture."
How Long Do Breast Implants Last?
Our team at Washington University began researching breast implant strength, durability and longevity 15 years ago. We have analyzed implants that have been in women's bodies for up to 32 years and found that the implant shell does not degrade in the body.4, 5 While there may be swelling of the shell due to contact with the silicone gel, our research has found that this swelling does not cause the implant to chemically degrade or rupture.6,7
As noted above, my own research, as well as my reading of the existing studies on the topic of silicone gel-filled breast implant rupture, have led me to conclude that the percent of third-generation silicone gel-filled breast implants that have ruptured is extremely low, amounting to approximately less than one percent per year.
Many other research teams have also explored the strength and durability of implants in the body. The research conducted to date can be grouped into several primary areas. First, there are studies that look at the strength and durability of silicone gel-filled breast implants and the actual percent of rupture – in other words, how many implants actually “fail” or rupture in the body? A second group of studies looks at the impact of ruptured implants on the body. This research is designed to determine whether there are any health effects associated with silicone leaking into the fibrous capsule or out of the capsule into the breast tissue or other parts of the body.
Studies Assessing Breast Implant Rupture:
According to the 1999 report on the safety of silicone gel-filled breast implants published by the IOM, studies conducted to evaluate breast implant durability identified implant rupture rates ranging from 0.3 percent to 77 percent.3 This is obviously a tremendous range, and there are several reasons for it. The biggest factor affecting the range of findings related to breast implant rupture is that investigators use different methods to determine the percent of failed implants.
One study of breast implant rupture that identified the highest percent of rupture (77 percent of women had at least one implant rated by radiologists as being ruptured or "indeterminate" after a median of 10.8 years in the body) suffers from selection bias (women volunteered themselves to participate). Also, approximately 70 percent of the implants were a specific type which have been found more likely to fail than implants made by other manufacturers. Another weakness of the study is that 92 percent of the implants could be classified as "second generation" devices, which are less likely to be intact than first- or third-generation implants.8 A later study of 144 Swedish women with newer-generation implants found that 0.3 -1.0 percent of implants ruptured after an average of six years in the body.9 Only one study to date directly examined breast implant rupture through repeated MRI examinations; epidemiologist Joseph McLaughlin, Ph.D. calls it the only "valid study of rupture incidence" published since the IOM released their landmark report in 1999. This study examined 317 third-generation implants and reported that 98 percent retained their integrity at five years and 83-85 percent retained their integrity at 10 years.10
In spite of the low percentage of ruptured devices, rupture is still an issue that is taken very seriously by breast implant makers and government organizations, such as the FDA. Breast implant manufacturers are continuously conducting retrieval and analysis studies to determine the modes and causes of implant rupture, and subsequently improve the performance of breast implants.
Causes of Implant Rupture
Implants can rupture for a variety of reasons. The cause of implant rupture is often determined by lab testing and/or analysis of the ruptured device. The United States Food and Drug Administration (FDA) has created a document that provides guidance for how ruptured implants should be analyzed. The analysis is based on a protocol developed by our group at Washington University.11 The FDA document recommends that scientists and technicians consider the following factors when evaluating the modes and causes of implant failure:
Although not specifically mentioned in the FDA document, "fold flaw failure" is another potential cause of implant rupture. A fold flaw failure can occur as a result of a crease or wrinkle developing in the shell of a silicone gel-filled breast implant. However, a fold in a shell does not guarantee that the implant will break.12
Are There Health Effects from Implant Rupture?
As a result of anecdotal reports from individual patients and physicians in the 1980s and 1990s, government organizations, medical professionals and women became concerned about the potential for long-term health effects associated with silicone gel-filled breast implant ruptures, particularly a group of autoimmune diseases called "connective tissue disorders" (CTDs). These include illnesses such as lupus, scleroderma and fibromyalgia. Since that time, researchers have looked extensively at what effect silicone may have if it escapes from the fibrous capsule.
When a silicone gel-filled breast implant ruptures, some women (especially those who have an extracapsular rupture) will experience symptoms such as a decreased breast size, a change in breast implant shape, hard lumps over the implant or chest area, pain or tenderness, tingling, swelling, numbness, burning or changes in sensation.13 In addition, silicone can migrate to other parts of the body, causing enlarged lymph glands (under the arms) or lumps known as granulomas that can be difficult or impossible to remove. While women who experience these symptoms are in no immediate danger, they should make an appointment to speak with their surgeon or physician as soon as possible. Based on the results of this discussion, implant removal may be warranted.
Beyond these symptoms, it is difficult to determine the longer-term health effects associated with breast implant rupture and silicone exposure. The 1999 IOM report concluded that "a review of the toxicology studies of silicones and other substances known to be in breast implants does not provide a basis for health concerns." Only one prospective study, published in 2004, has looked at the possible health implications of ruptured silicone gel-filled breast implants in the body.14 Researchers looked at 64 women with implant ruptures diagnosed by MRI and followed their health status for two years before conducting another MRI. They compared these women against a group of similar women who had implants but no evidence of rupture. The researchers found no increase in breast hardness or levels of antibodies that suggested the potential for autoimmune or connective tissue disorders. Women with verified ruptures did report a significant increase in non-specific breast changes compared with women who did not have ruptures. The researchers concluded that, "for most women, rupture is a harmless condition which does not appear to progress or to produce significant clinical symptoms."14
Another study looking specifically at the risk for connective tissue disorders (CTD) in women with breast implants found no significant differences in definite CTD between women with intact implants and women with ruptured implants.15
Some women may have an implant rupture, but experience no symptoms. This is known as a "silent" rupture, and is generally best identified through MRI. The FDA has recommended that women consider having MRIs to screen for silent rupture starting at three years after implantation and then every two years thereafter.16
Breast Implant Structure and Rupture Q&A
Will my silicone breast implant rupture during mammograms or physical activities?
Today's implants are designed to withstand more than 25 times the force of a normal mammogram without failure.17 This means that a silicone gel-filled breast implant is very unlikely to rupture during routine physical activity or during a routine mammogram. If you have implants, do not change the mammogram screening schedule you have agreed on with your physician – the risks of not detecting a cancer because you avoid a screening far exceed any risk of damage to the implant. Ask your physician to direct you to a screening facility that practices a breast implant displacement technique, which has been shown to improve the accuracy of mammograms in women with breast implants.
It is important to put the potential for rupture into perspective: ruptures are relatively rare events. According to results from a core study of 715 women conducted by one breast implant manufacturer (Allergan), approximately one percent of implants had a reported rupture at four years.17 Silicone gel-filled breast implants have been successfully used in Europe for more than 25 years; a considerable number of European women have had their original implants for more than 14 years.
Much like other medical devices, though, silicone gel-filled breast implants are not intended to last a lifetime. It is possible that at some point, the implant(s) may need to be removed or replaced. Therefore, you and your physician should monitor the integrity of your implant. The FDA has recommended that MRIs be considered to screen for silent rupture (rupture that occurs without any noticeable physical or medical symptoms) starting at three years after implantation, and then every two years thereafter.
What can I do to help ensure my implants last as long as possible?
To start, find a surgeon who has significant experience with breast implants. The more experience your surgeon has, the less likely it is that he or she will damage the implant during implantation. In addition, select an implant from a reliable manufacturer, specifically a manufacturer whose implants have been approved for use by the FDA.
What if my silicone gel-filled breast implant ruptures? Is my health at risk if rupture occurs? Is the silicone harmful if it leaks?
Although recent studies have confirmed that there is no immediate danger to your health, if you suspect that your breast implant may be ruptured and leaking, you should consult with your plastic surgeon. MRI testing may be required to confirm a rupture. If a rupture is confirmed, you should have the implant removed and work with your surgeon to determine if you want to replace the ruptured implant.
As noted above, you may experience local symptoms, such as pain, tenderness or swelling, if your silicone gel-filled breast implant ruptures. Again, these symptoms should be shared with your doctor to determine the best course of action to address them.
Also as noted above, there has been considerable discussion about the safety of silicone in the body. The 1999 Institute of Medicine report concluded that “a review of the toxicology studies of silicones and other substances known to be in breast implants does not provide a basis for health concerns.”
How will I know if my implant has ruptured?
Complications of implant rupture reported in published literature include breast hardness, a change in breast shape or size, breast pain or tenderness, tingling, swelling, numbness, burning, or changes in sensation. Any of these should be reported to your physician.
Again, remember that ruptures in silicone gel-filled breast implants may be “silent,” which means there may not be symptoms and the rupture may not be easily diagnosed through clinical examination. Patients are advised to consult with their physician on a consistent basis. If a silent rupture is suspected, the physician may recommend a mammogram, MRI (magnetic resonance imaging) or removal of the implant.
In any case, the US FDA recommends that women with breast implants should have their first MRI three years after the initial implant surgery, and then every two years after.
Where can I find more information about the durability of silicone gel-filled breast implants?
1 Peters, N. "Current Status of Breast Implant Survival Properties and the Management of the Woman with Silicone Gel Breast Implants." Jour. of Plastic Surgery. 2000. 8:54
2 The Food and Drug Administration. "Draft Guidance for Industry and FDA Staff: Saline, Silicone Gel and Alternative Breast Implants." November 2006; www.fda.gov/cdrh/ode/guidance/1239.pdf
3 Bondurant S, Ernster V, Herdman R. "Safety of Silicone Breast Implants, Report of the Committee on the Safety of Silicone Breast Implants, Institute of Medicine." Washington, D.C.: National Academy Press, 1999.
4 Brandon, HJ, et. al., "Biodurability of Retrieved Silicone Gel Breast Implants." Plast and Reconstr. Surg. June 2003; 111(7):2295-2306.
5 Brandon, HJ, et. al., "In Vivo Aging Characteristics of Silicone Gel Breast Implants Compared to Lot-Matched Controls." Plast and Reconstr Surg. 2002; 109(6): 1927-1933.
6 Brandon, HJ, et. al., "Discussion of Silicone Gel Breast Implant Failure: Evaluation of Properties of Shells and Gels for Explanted Prostheses and Meta-Analysis of Literature Rupture Data." Ann of Plastic Surgery. 2002; 49)3):16-21.
7 Wolf, CJ, et. al., "The Effect of Cyclic Swelling (Octamethylcyclotetrasiloxane) on the Physical Properties of Silicone Breast Implants." J Biomater. Sci. Polymer Edn, 2002; 13(1):27-41.
8 Brandon, HJ, et. al., "Letter of Reply to the Discussion of Silicone Gel Breast Implant Failure: Evaluation of Properties of Shells and Gels Explanted Prostheses and Meta-Analysis of Literature Rupture Data." Annals of Plastic Surgery, 2003; 51(3):334-336.
9 Heden, P. et. al., "Style 410 Cohesive Silicone Breast Implants: Safety and Effectiveness at 5 to 9 years After Implantation." Plast. Reconstr. Surg. 2006;118(6):1281-1287.
10 Holmich, LR, et al. "Incidence of Silicone Breast Implant Rupture." Arch Surg 2003;138(7):801-806.
11 Brandon, et. al. "Protocol for Retrieval and Analysis of Breast Implants." J Long-Term Effects of Med Implants, 2003; 13:49-61.
12 Brandon, HJ, et. al., "Morphology of Breast Implant Fold Flaw Failure." J Long-term Effects of Med Implants, accepted for publication 2007.
13 FDA Breast Implant Consumer Handbook 2004. http://www.fda.gov/cdrh/breastimplants/indexbip.PDF
14 Holmich, LR, et al. "Untreated Silicone Breast Implant Rupture." Plast Reconstr Surg 2004;114(1):204-216.
15 Holmich LR, et al. "Self-Reported Diseases and Symptoms by Rupture Status Among Unselected Danish Women with Cosmetic Silicone Breast Implants." Plast Reconstr Surg 2003;111(2):723-732
17 INAMED Silicone-Filled Breast Implants Approval Press Release, November 17, 2006: http://www.shareholder.com/agn/ReleaseDetail.cfm?ReleaseID=219163