Breast Implants

V. (d) Silicone breast implants.

• What is silicone?
• History of breast implants.
• Modern generation of breast implants
• Who can have silicone? Who qualifies?
• What about all the silicone problems? Are they Safe?

Breast implants come in many shapes and sizes, with differing inner and outer materials. Together, you and Dr. Mendieta will select the options that are best suited for you and most likely to achieve the results you desire.

All breast implants have an outer pliable envelope enclosing either a liquid (saline) or soft-solid (gel) substance.

To achieve fullness and create the most natural breast-like feeling possible, the implants are filled with either:

• saline (salt water) or
• silicone gel, a soft-solid (gel) substance.

What is silicone?

Silicone is derived from silicon, a semimetallic or metal-like element that in nature combines with oxygen to form silicon dioxide, or silica. Beach sand, crystals, and quartz silica. In fact, silica is the most common substance on earth.

Silicon can be produced by heating silica with carbon at a high temperature. Further processing can convert the silicon into a long chemical chain, or polymer, called silicone- which can be a liquid, a gel, or a rubbery substance.

Various silicones are used in lubricants and oils, as well as in silicone rubber. Silicone can be found in many household items, such as polishes, suntan and had lotion, antiperspirants, soaps, processed foods, waterproof coatings, and chewing gum. Because silicone is relatively compatible with human tissue, it has been used in many types of implants, including breast.

Several processes have been used in treating and making ready silicone for implants. The most common product of these processes is platinum-cured gel or liquid rubber, which was used in early implants. Other processes prepare the silicone for use in implants; however, all of these procedures require a final oven bake to ensure their purity and stability.

Noncrystalline silica is amorphous (shapeless) and is less toxic than the crystalline form. Amorphous silica powder is used in most silicone shells (elastomeres). Although concerns have been raised that the silica in these shells can travel to breast tissue, experimental studies have not found amorphous silica in tissue near implants. Another worry voiced is that the amorphous silica could convert to sand (crystalline silica) within the body, but this is a chemical impossibility. No crystalline silica has been found in women with implants.

History of breast implants.

Attempts to improve the look of the breast by augmentation its size and shape date back to the late 1880's. Among the materials inserted in breast early on were ivory, glass balls, ground rubber, ox cartilage, and sponges, sacs and tapes made from various synthetic substances. Later came rubber, Teflon and silicone.

Some breasts were augmented by injection. In the 1940's, an array of liquid substances were injected into the breast, such as paraffin and petroleum jellies. Later, Industrial silicone fluid and medical-grade silicones were injected in to the breast by unlicensed practitioners, sometimes in staggering amounts. These methods of breast injection caused pain, discoloration, ulceration, infection, disfigurement, breast loss, liver problems, respiratory distress and pulmonary embolism, and even coma and death. The frequency of capsular contracture with pre-silicone implants may have reached 100%. Between 12,000 and 40,000 women received breast injections in Las Vegas before the procedure was declared a felony under Nevada State Law in 1976.

Modern generation of breast implants

In 1963, Dow Corning Corporation introduced the first silicone-gel-filled implant. The earliest Dow shells had a high-molecular-weight gum filled with amorphous silica, and the gel in the implant was platinum cured. By the early 1970's, the Dow Corning Dacron-patched implant had achieved stunning popularity, accounting by one estimate for 88% of all implants sold.

These early implants had a thick shells and gels. The silicone rubber elastomer shell usually had seams and smooth surface. The inside contained a firm silicone gel and fluids. Rupture rates were low because of the tough shell, but complication from capsular contractures were common and gel-filled seepage was probably considerable.

Some implants had internal dividers to keep the gel from sagging into the central part of the implants. Seal patches were used to close up any holes or slits left by manufacturers or the valve entrance to an expander, and are still used for manufacturing today's seamless implants.

By the late 1960's, Dow's shells had become less thick and were seamless. And in 1968, Heyer Schulte Corporation became the first domestic manufacturer of saline filled implants. Early saline implants were fragile and heavy, with audible sloshing, and there was very high deflation rates up to 76%, probably because of the high temperature vulcanizing process used to cure or strengthen the contents.

The original thick-shell models were replaced in the 1970's and early 1980's by implants with thin shells. But these had a greater tendency's to rupture and deflate. These second generation implants were generally smooth surfaced and had high contracture and gel-fluid seepage rates. More flexible gels were introduced by various companies from 1972-1975, and thinner elastomer shells were introduced staring in 1972.

Another development in the 1970's was a polyurethane foam coating on the implant shell. This coating appeared to reduce contracture and was popular; and estimated 110,000 women or more received this type of implant before it was discontinued in1991. Polyurethane coating appeared to diminish capsular contracture by causing an inflammatory reaction. This reaction discouraged formation of fibrous tissue around the capsule. But the polyurethane coating started disintegrating almost immediately , so that what eventually remained was a mostly smooth implant surrounded by a capsule containing foam fragments. Pain, fluid accumulation, and infection were reported. The foam fragments were one reason a polyurethane-coated implant was difficult to remove.

There is no hard evidence to support the idea that the polyurethane foam could lead to cancer. Beginning in the mid 1980's, most implants models were sold with a textured shell surface. The theory of texturing was similar to that of the polyurethane coating; that is, the growth of tissue into the irregular spaces of the shell would prevent collagen and other fibrous tissue form forming excess growth around the implant capsule.

Textured Implants might also encourage the development of synovium, a thin membrane that secretes synovial fluid, a clear, sticky substance. Synovium may be a natural result of friction form the movement common in all breast implants.

Another innovation in the second-generation implants was the double lumen. These implants had two cavities and two shells, which were either patched together or had one shell floating freely inside the other. The double lumen was an attempt to provide the cosmetic benefits of gel in the inside cavity, while the outside lumen contained saline and could be used for an expander or even for injection of antibiotics or steroids. The saline lumen was also thought to control contracture and gel and fluid seepage or rupture, but studies over the years have largely disproved such theories.

Various types of expanders evolved over the years, some of the them with permanent valves. A barrier coating on the inside of the shell was developed in the 1980's to help prevent silicone-gel bleeding or seepage. Rupture frequencies for silicone-gel implants were as follows:

• First generation form 1963-1972- Very Low
• Second generation form 1972- to mid 1980's 50-95% after 12 or more years,
• Third generation from mid-1980's to present still uncertain, but possibly about 10% in 5 years.

This modern third generation of implants, which dates from the mid-1980's, also saw improved silicone-gel implants, saline implants with much better deflation rates, and stronger shells with barrier layers and texturing. Although these data are incomplete, this generation of implants may offer lower rates of deflation and rupture, fewer contracture and less gel diffusion or bleeding.

There was no standard breast implant in America. Since 1962, there have been some 240 different types, made by at least 10 manufacturers. Given variations in sizes and shapes, types of valves and patches, gels, shells, one estimate puts at 8,300 the number of different implants available with slight variations over the years.

A majority of implants in place today are single-lumen (one-cavity) models filled with silicone gel. The shell (elastomer) is made of silicone rubber and has an inside barrier coating of fluorosilicone or a modified layer of elastomer to help prevent silicone fluid from escaping. The outside of the shell often has a textured surface; tissue grows into this surface, stimulating an inflammatory reaction. This inflammation can delay the development of the fibrous tissue that causes capsular contracture.

In the 1990's, saline-filled, single-lumen implants almost completely replaced the formerly popular gel-filled models because of the 1992 FDA moratorium on the use of silicone gel. In addition, the popularity of immediate implant reconstruction after mastectomy has grown, for 3% of implants in 1983 to more that 25% in 1992. Reconstruction with implants reached its zenith of 40% of all implants in 1990; since them, more women have chosen to have a breast constructed out of tissue from other part of the body ( the flap form of reconstruction). But this is a more difficult operation and suitable for all women.

It remains to be seen whether implants of this third generation will continue to be used or if forthcoming study results (and FDA decisions) will bring about yet another generation of implants. Furthermore, there is less information available about saline implants than silicone-gel implants gel was the fill of choice until the 1990's. Saline implants contain a harmless saltwater solution, it cannot have silicone leakage (because they don't contain silicone), and appear to have lower rates of capsular contracture. Still, the jury will be out until more studies are forthcoming.

Who can have silicone? Who qualifies?

By governmental dictum, breast augmentation patients are eligible for only saline implants. Silicone gel-filled implants at this time are available only to select patients. They must be female, at least eighteen years of age, and willing to participate in the study. Federal law requires patients using gel-filled implants to participate in a mandated Mentor Adjunct Study.

In order to become part of the study you must meet one of the following criteria.

Inclusion criteria:

1. History of treatment for breast cancer or trauma resulting in loss of a breast

2. Congenital deformities such as chest wall defects with abnormalities of the ribs, sternum, or muscle

3. Severe asymmetries of the breast

4. Tuberous breast deformity (breast beneath nipple narrowed like a tube) link to tuberous

5. Severe ptosis of the breast requiring a mastopexy (breast lift) link to ptosis

6. Replacement or revision of implants for whom saline implants are not suitable e.g., thin skin, insufficient tissue, severe rippling of saline implants

7. Breast augmentation in the opposite uninvolved breast to provide symmetry

Exclusion criteria:

1. Presence of infection

2. Pregnancy or nursing

3. Diagnosis of Lupus or Scleroderma

4. Uncontrolled diabetes or other disease with impaired wound healing

Women involved in the study will need to sign an informed consent and agree to come back for a six-month postoperative visit as well as yearly visits through ten years.

Keep in mind that women who wish to have silicone for purely cosmetic reasons, whether they fit the above criteria or not, may be able to have silicone if they agree to be part of a current silicone study. You need to use a participating surgeon and agree to be followed in the trial for a number or years. ( most of the women considering silicone implants for cosmetic reasons qualify if you need a breast lift)

To see if you qualify for silicone breast augmentation and are interested in participating in this study, contact us and if possible email your photos.

What about all the silicone problems? Are they Safe?

In 1992 the FDA declared a moratorium on silicone implants. This halt on the use of the implants was because of lack of information on the safety of silicone and on reported problems with women developing autoimmune diseases and general medical problems. The safety of the implants was questioned and its use was banned until further studies could be developed and its safety determined. In 1993 the FDA also notified the manufacturers of saline implants that they to were required to keep records and submit data on its effectiveness and safety, however these saline implants were allowed to stay on the market.

This moratorium launched many scientific studies that set out to prove the safety of these implants. Although the studies continue several major findings have been brought out by the Institute of Medicine (IOM). This is a branch of the the National academy of sciences which was selected by the FDA to spear head and lead the research on Silicone safety. There findings to date are as follow:

The IOM committee review of the research and medical studies shows a local, but not a general, reaction to silicone breast implants.

1. There is no evidence that the silicone implants are responsible for any major disease of the the whole body. Women are exposed to silicone constantly in their daily lives.

2. There is no plausible evidence of a novel autoimmune disease caused by implants

3. The committee found no increase in either primary or recurrent breast cancer in women with breast implants. Some studies even suggest lower rates of breast cancer in implanted women. (perhaps because they have less breast tissue)

4. There is no danger in breast feeding: cow's milk and infant formulas have a far higher level of silicon, a silicone component, than mother's milk. Breast milk is the best food for babies.

5. The major problem with implants are local, but not life-threatening, complications. These include implant removal, ruptures, deflations, capsular contracture, infection, and pain.

6. Many women will have secondary problems such as severe contracture, rupture, and implant removal.

7. Implants do not last forever: risks accumulate over time, and many women should expect to have more than one implant. However if no problem develops implants do not need to be changed

8. Some women with breast implants are indeed very ill. However, the committee can find no evidence that these women are sick because of their implants.

The committee studied and evaluated multiple documents on the history, chemistry, and toxicology of the silicone implants. It noted that the wide use of silicone- in foods, cosmetics, lubricants, and in a variety of consumer products- has resulted in extensive exposure to it by individuals in all developed countries.

Almost all studies agree that there are baseline levels of silicon, an indicator of silicone, in normal breast and other tissues. Silicon is found in moderately higher than baseline levels around saline implants and in the capsules around silicone-gel implants. Silicon levels particularly high around ruptured silicone implants. This silicon apparently does not travel to other parts of the body. The committee found that the exposure for women to silicone from the breast implants is limited to almost entirely to the implant, its capsule and the tissue and lymph nodes immediately surrounding the area.

The IOM committee concluded that the silicon found in distant tissues most likely reflects human exposure to the widespread presence of silicon and silicone in the environment. At the end of the investigation, the IOM committee concluded that the silicone found in breast implants do not provide a basis for concern at doses reasonably to be expected.

In general silicone is safe.