Article: Breast implant

A breast implant is a prosthesis used to enlarge the size of a woman's breasts (known as breast augmentation) for cosmetic reasons, to reconstruct the breast (e.g. after a mastectomy or to correct genetic deformities), or for the purposes of male-to-female gender reassignment surgery.

According to the American Society of Plastic Surgeons, breast augmentation is the third most commonly performed cosmetic surgical procedure in the United States. In 2005, 291,000 breast augmentation procedures were performed.^[1]

There are two primary types of breast implants: saline and silicone gel implants. Saline implants have a silicone rubber shell filled with sterile saline liquid. Silicone gel implants have a silicone shell filled with a viscous silicone gel.

History

Implants have been used since 1895 to augment the size of women's breasts. The earliest known implant occurred in Germany, using a woman's own adipose tissue (from a lipoma, a benign growth, on her back). ^[2]

The idea of using silicone to increase breast size began after World War II, when industrial grade silicone was injected in the breasts of women in Japan. According to Dr. Norman Anderson, a Dean at Johns Hopkins Medical School and advisor on silicone breast implants to the Food and Drug Administration, silicone injections subsequently became popular among women in the adult entertainment industry in Las Vegas and elsewhere in the U.S., and approximately 50,000 women received "illicit silicone liquid injections to augment their breasts." ^[3] Even when the silicone was "medical grade" he described the results as "disastrous" with inflammatory granulomas, silicone extruding through holes in the breast and "massive necrosis and scarring." Silicone injections were replaced by implants filled with silicone in the 1960's; the silicone elastomer shell was intended to keep the silicone gel and silicone oil from harming breast tissue or migrating to other organs. Nevertheless, silicone injections were still used for breast augmentation in Asia as late as 1995, despite these known problems. ^[4] Development of silicone granulomas and hardening of the breasts were in some cases so severe that women needed to have their breasts removed in surgery similar to mastectomies. Women sometimes seek medical treatment for complications up to 30 years after receiving this type of injection.

Indications

Clinical indications for the use of breast implants are for breast reconstruction, gender reassignment surgery, and for other abnormalities that affect the shape and size of the breast. In some countries health insurers will reimburse insertion of breast implants only for these indications. Non-clinical indications (the most common reasons) are cosmetic.

Breast implants may be contraindicated in body dysmorphic disorder, since women with that disorder have a distorted sense of their own body. This may result in repeated plastic surgery for perceived imperfections.^[5]

Types of implants

Silicone gel implants

Thomas Cronin and Frank Gerow, two Houston, Texas, plastic surgeons, developed the first silicone breast prosthesis with the Dow Corning Corporation in 1961. The first woman was implanted in 1962. The implant was made of a silicone rubber envelope (or sac), filled with a thick, viscous silicone gel.^[6]

When originally introduced in the 1960s, medical devices were not regulated in the United States, and therefore no safety data were required. After the law was changed in 1976 to give the Food and Drug Administration (FDA) the authority to regulate all medical devices, the FDA "grandfathered" many devices that were already on the market, including breast implants. As a result, these devices could continue to be sold although they had not been through the FDA approval process and long-term safety had never been documented. In 1991, the FDA required that safety studies be submitted by companies that sought to keep their implants on the market in the U.S. The FDA reviewed the data submitted by several implant manufacturers, and determined that the data were not adequate to prove safety. In 1992, the FDA therefore restricted silicone gel-filled breast implants to clinical trials, primarily for women needing reconstruction after mastectomy or breast deformity, or for women with implants that need to be replaced. The FDA has not lifted those restrictions, despite several subsequent applications for approval.^[7]

In Canada, silicone gel-filled prostheses were banned by Health Canada on January 6, 1992 in response to concerns raised in the scientific literature regarding possible illnesses associated with the implants. In 1999, Health Canada's Medical Devices Bureau began to make silicone implants available to plastic surgeons again under a Special Access Program. Under the program, surgeons must submit requests to use silicone implants to the Bureau on a case-by-case basis.^[8]

First and second generation

The first generation Cronin-Gerow implants were redesigned in the 1970's with thinner gel and thinner shells. These "second generation" implants had a greater tendency to rupture and leak, or "bleed" silicone through the porous shell, and complications such as capsular contracture were also quite common.

Another development in the 1970s was a polyurethane foam coating on the implant shell. According to a Congressional report an estimated 200,000 women received this type of implant before it was discontinued in the early 1990s because of health concerns.^[9] Polyurethane coating was believed to diminish capsular contracture by causing an inflammatory reaction that discouraged formation of fibrous tissue around the capsule. The manufacturer later withdrew the product after FDA scientists determined that the foam broke down to TDA, a known animal carcinogen.^[10] Plastic surgeons have found that removing polyurethane-coated implants can be disfiguring and lead to chronic infection, drainage from the breast and skin ulceration.^[11] While still manufactured in Europe and South America, these implants are not FDA approved for sale in the United States.^[12]

Second-generation implants also included various "double lumen" designs. These implants were essentially a silicone implant inside a saline implant. The double lumen was an attempt to provide the cosmetic benefits of gel in the inside lumen, while the outside lumen contained saline and its volume could be adjusted after placement. The failure rate of these implants is higher than for single lumen implants.^{[citation needed]} The contemporary versions of these devices ("Becker Implants") are used primarily for breast reconstruction.

Third generation

Silicone gel-filled breast implants (3rd generation)

Third-generation implants, developed in the late 1980's and early 1990's, used thicker shells that were coated to decrease gel bleed, and a thicker, more cohesive gel filler.

These implants are sold under restricted conditions in the U.S. and Canada, and more widely used in other countries. Two companies, Inamed and Mentor, applied for FDA approval for these implants in 1991 and 2003, and were rejected, and have resubmitted applications currently being considered by the FDA. These implants rupture as they age, and the rate of rupture has not yet been determined. Data presented to the FDA is limited to 3 and 4 year data. The increased cohesion of the gel filler is believed to reduce leakage of the gel compared to earlier devices, but no long-term studies have been conducted to compare leakage rates. FDA studies indicate that most women with these implants will have at least one ruptured implant within 11 years. One study funded by Dow Corning estimates that "at least 15%" of these implants rupture within the first 10 years, which translates to at least 30% of breast augmentation patients.^[13]

Cohesive gel implant

Fourth generation

Evaluation of "gummy bear" or high-cohesive, form-stable implants is in preliminary stages in the United States. Although these implants are used more widely in other countries, there are no published long-term safety studies. It is speculated that the high degree of gel cohesion in these implants is likely to eliminate or significantly reduce silicone migration. ^[14][15][16]

Saline-filled breast implants

Saline implants

Saline-filled breast implants were first manufactured in France in 1964, introduced by Arion^[17] with the goal of being surgically placed via smaller incisions. These original devices had a high failure rate and were discontinued in the early 1970s. The current devices are manufactured with thicker, room temperature vulcanized (RTV) shells. These shells are made of silicone elastomer and the implants are filled with salt water after the implant is placed in the body. Since the implants are empty when they are surgically inserted, the scar is smaller than is necessary for silicone gel breast implants (which are filled with silicone before the surgery is performed).

Until 1992, most women getting breast implants used silicone gel implants rather than saline. After the FDA silicone gel implant moratorium in the U.S., Canada, and several other countries in the early 1990's, saline implants became the most popular type in the United States. Saline implants made by Inamed and Mentor were approved by the FDA in 2000. Saline implants made by other companies have not provided the FDA with sufficient safety data to gain FDA approval, but are sold in other countries.^[18]

Local complications for saline breast implants are similar to those for silicone gel implants, and can be dangerous, debilitating, or relatively minor. The most common complications are capsular contracture and the need for additional surgery to fix implant problems or to remove ruptured implants. Other common complications include infection, chronic breast pain, and loss of nipple sensitivity. According to data provided by Inamed and Mentor to the FDA, most saline breast implant patients have at least one serious complication within the first 3 years.[2][3].

Cosmetic problems can result in a dissatisfied patient but are not medically worrisome. Compared to silicone gel implants, saline implants are more likely to cause cosmetic problems such as rippling, wrinkling, and be noticeable to the eye or the touch. Particularly for women with very little breast tissue, or for post-mastectomy reconstruction, some plastic surgeons believe that silicone gel implants have a better cosmetic outcome. In patients with more breast tissue, however, saline implants look very similar to silicone gel.

In addition, case reports of bacteria and fungal contamination have been described in medical journals.

Advantages of saline implants include easier removal, no silicone leakage, and lower cost (several hundred dollars less per implant than silicone). Another advantage is that the size of the implant can often be slightly adjusted without replacing the implant.

There are no long-term studies to determine if saline breast implants increase the risk of diseases such as cancer or autoimmune disease. However, breast implant manufacturers warn patients that women with autoimmune diseases were excluded from their safety studies of saline bresat implants because of concerns about the risks. [4]

Local Complications

Local complications specific to breast implants include the following:[5][6][7][[8]

Rupture

Intracapsular rupture - with capsule created by the body to wall off (silicone implant) foreign object

Extracapsular rupture - Single lumen silicone implants ruptured a few years before their removal in 2004

Implants do not last a lifetime. When saline breast implants break, they often deflate quickly and can be easily removed. However, when silicone implants break they rarely deflate, and the silicone from the implant can leak and migrate outside of the scar tissue that the body creates around the implant. This is known as "extracapsular silicone", which can migrate to other parts of the body. Extracapsular silicone can cause granulomata (inflammatory nodules) and axillary lymphadenopathy (enlarged lymph glands in the armpit area).[9]

The health risks of rupture are not known, but the cosmetic risks are clear, with some women losing much of their breast tissue when the silicone has leaked. The potential risks of silicone migration are still controversial.

A 2000 FDA study stated that rupture is a concern because:

1. Rupture of silicone gel-filled implants may allow silicone to migrate through the tissues to the lymph nodes and from there to organs such as the lungs, where it can't be removed.
2. The health effects of leaking silicone is unknown.
3. Implant rupture is a device failure - the implant is no longer performing as intended.[10]

In 2005, scientists confirmed the presence of silicone and polyurethane in the lymph nodes in patients with silicone breast implants. ^[19]

The age of the implant is an important factor in rupture. The FDA rupture study was superior to previous rupture studies because it was limited to women who had silicone gel implants for at least 6 years and had not removed their implants or reported problems with them. Based on magnetic resonance imaging (MRI) they found that 77% of the women had at least one ruptured implant, even though most had no symptoms and were unaware of the leakage.^[20]

Since the research indicates that most ruptures of silicone gel implants are "silent," with no symptoms, the FDA recommends MRIs as the gold standard for detecting rupture. The FDA General and Plastic Surgery Advisory Panel has considered recommending annual MRIs, but determined that the cost would be prohibitive for screening purposes. However, manufacturer data clearly indicate that clinical exams are inadequate to rule out suspected rupture.^[21]

Capsular contracture

Capsules of tightly-woven collagen fibers form as an immune response around a foreign body (eg. breast implants, pacemakers, orthopedic joint prosthetics), tending to wall it off. Capsular contracture occurs when the capsule tightens and squeezes the implant. This contracture is a complication that can be very painful and distort the appearance of the implanted breast. The exact cause of contracture is not known. Correction of capsular contracture includes a range of treatments depending upon the grade of contracture from manual massage to surgical removal of the implant capsule or removal (and possible replacement) of the implant itself.

Hematoma/seroma

Hematoma is a collection of blood inside a body cavity and a seroma is a collection of the watery portion of the blood around the implant or around healing. A small scar can form or a rupture may occur if the implant is damaged during draining the incision. Post-operative hematoma and seroma may contribute to infection or capsular contracture.

Changes in nipple and breast sensation

Feeling in the nipple and breast can change after implant surgery. Changes vary from intense to no feeling in the nipple or breast after surgery. This altered sensation can be temporary or permanent and may affect sexual response or the ability to nurse a baby.

Extrusion

Unstable or weakened tissue covering and/or interruption of wound healing may result in extrusion, (when the breast implant comes through the skin). Surgery needed to correct this can result in unacceptable scarring or breast tissue loss.

Tissue atrophy/chest wall deformity

Pressure of the breast implant may cause the breast tissue to thin and shrink. This can occur while implants are still in place or following implant removal without replacement.

Mammography

Doctors recommend that women with breast implants have mammograms. However, according to the FDA, pressure on the breast (compression) during mammography can cause implant rupture. In 2004, Brown et al reported that the FDA had received dozens of reports of implants rupturing or leaking during mammography.[20]

Breast implants also can interfere with the accuracy of mammograms because the implant appears as a solid white shape, obscuring tumors above or below. Specific mammogram techniques have been developed to ensure that as much breast tissue as possible is examined in the woman with implants. This requires taking extra images, called displacement views, which expose the woman to more radiation. In 2004, Miglioretti and her colleagues published a study in the Journal of the American Medical Association indicating that 55% of breast tumors were not initially detected on mammograms for women with implants, even though the extra images were used. ^[22] This compares to about 30% of tumors that were not initially detected for women who did not have breast implants. These tumors were subsequently detected in later mammograms.

In addition to making tumors more difficult to detect, implants cause "false positive" results when extensive scarring and calcium deposits mimic the appearance of cancer, making the deposits difficult to distinguish from tumors on a mammogram. Calcium deposits may be felt as modules or bumps under the skin around the implant [19] Biopsy may be necessary to determine whether these are cancerous.

Ultrasound and MRIs can be used to detect breast cancer instead of mammograms, but this adds to the cost of screening and probably would not be covered by health insurance.

Controversy

Systemic illness

Thousands of women have claimed that they have become ill from their implants, particularly when silicone implants ruptured. Complaints include systemic fungus, neurological and rheumatological problems. Although information from hundreds of individual reports is considered anecdotal, peer-reviewed studies indicate that subjective and objective symptoms of many women with implants improve when their implants are removed. For example, in a comparison study, women with rheumatological symptoms who had their implants removed and not replaced reported improvement in their health, and women whose implants were not removed or removed and replaced did not."^[23]

Numerous reports, based primarily on studies funded by Dow Corning, have reported that there is no evidence of increased mortality or classically defined autoimmune diseases among women with silicone breast implants. These include the Canadian Expert Advisory Committee review in 1992, ANDEM in France in 1996, the UK Independent Review Group 1998, and the U.S. Institute of Medicine in 1999, and the Scientific Technical Opinions Assessment (STOA) report commissioned by the European Parliament in 2001 (updated in 2003).

As studies have followed women with implants for a longer period of time, evidence has grown regarding serious systemic symptoms. A Danish study, funded by Dow Corning and the Danish Cancer Society, reported that women who had breast implants for an average of 19 years were significantly more likely to report fatigue, Raynaud-like symptoms (white fingers and toes when exposed to cold), and memory loss and other cognitive symptoms, compared to women of the same age in the general population. ^[24] The researchers seemed to ignore these findings when they concluded that long-term exposure to breast implants "does not appear to be associated with autoimmune symptoms or diseases".

A large study by the National Cancer Institute found a decreased standardized mortality ratio in breast implant augmentation patients and other plastic surgery patients, reflecting the fact that plastic surgery patients tend to be healthier and more affluent than the general population.^[25] However, the women with implants were twice as likely to die from lung cancer compared to other plastic surgery patients, with no evidence of a difference in smoking history. The implant patients did not have an increased risk of death from breast cancer compared with either the general population or other plastic surgery patients

Platinum

Platinum is a catalyst used in the making of silicone implant polymer shells. The literature indicates that the platinum leaches (leaks) from these implants and is present in the surrounding tissue. FDA reviewed the available studies from the medical literature on platinum and breast implants in 2002; however, the studies had evaluated platinum in the implants, but not in the women's bodies. ^[26]

In May 2006, researchers published a peer-reviewed study concluding that "women exposed to silicone breast implants have platinum levels that exceed that of the general population." ^[27] This was the first report "to document the various platinium oxidation states present in samples from women exposed to silicone breast implants." The study reported that platinum migrates from silicone implants via the lymphatic and blood systems and may accumulate, persisting years after the silicone gel breast implants have been removed. Women with silicone breast implants had approximately 100 times higher platinum levels in their breast milk than women with no known platinum exposure. Platinum levels were as much as 1,700 times higher in urine. However, more important than the levels of platinum was the oxidation state; the platinum in breast milk and other body fluids was ionized, in the form of platinum salts, and therefore potentially toxic.

The FDA reviewed the study, criticized the small sample, and noted that previous research reviewed by Brook, an Inamed consultant, has indicated that the platinum in implants is not ionized and therefore would "not represent a significant risk to women." [11] According to the FDA website, the FDA has been asked to conduct additional research by researchers without financial ties to implant makers, to replicate or refute the study of ionized platinum in the bodily fluids of women with breast implants.

Repair or revision surgery

Regardless of the type of implant, it is likely that women with implants will need to have one or more additional surgeries (reoperations) over the course of their lives. Common reasons for reoperations include cosmetic concerns, capsular contracture, and rupture.^[28] Reoperation rates are more frequent in breast reconstruction cases. The major implant manufacturers, Mentor and Inamed, both reported that almost half their reconstruction patients underwent additional surgeries within three years to fix implant problems, whether their implants were silicone or saline. The exact statistics are available on the FDA website.

More than 50,000 implant removal procedures were also reported in 2004. In fact, the American Society of Plastic Surgeons reports that in 2000, about 26% of augmentation and 16% of reconstruction surgeries were for replacement of implants—due to capsular contracture, rupture, implant shift, chronic infection, or other causes. ^[29]