Women are justifiably concerned about the safety of the silicone gel breast implants available today as an option for cosmetic breast augmentation/enhancement and breast reconstruction procedures. Breast implants have been in use for about 50 years. The first pair of silicone gel implants were inserted in 1962, saline implants became available as an alternative option in 1965. Silicone gel implants remained the dominant preferred implant utilized during the thirty years that followed. But in 1992, a moratorium on the use of silicone gel implants was issued by the FDA citing the need for more in depth research and concern over safety issues. Saline implants, fully approved by the FDA, essentially became the only type of implant used by plastic surgeons for breast augmentations and breast reconstructions for the next 10 + years. But after almost 15 years of extensive research and as a result of many changes made in the manufacturing process, the silicone gel breast implants we have in current use received their FDA approval (in 2006). Over 300,000 breast implant operations are performed annually in the USA, with approximately equal numbers of saline and silicone gel implants being placed. About 80% are cosmetic (breast augmentation/enhancement), and 20% are reconstructive (after a mastectomy) in nature. Breast implants are the most commonly used method for the reconstruction of the breast due to surgical removal for breast cancer.
Silica (silicon dioxide) is the most common substance on earth and is the key element comprising sand, crystals and quartz. In the laboratory silica is combined with carbon and linked in long chains (polymers) to create silicone, more properly chemically known as polydimethylsiloxane (or PDMS) . Chemical manipulations of the arrangements of the polymer chains can yield different forms of PDMS, as is the case for the silicone implant shell compared to the actual silicone gel inside.
Medical grade silicone has been a part of so many consumer products for so many years that one would probably be able to find some traces of silicone in every person of modern society on earth! Did you know that silicone is used to coat every needle and every syringe used all over the world for medication injections? Silicone also coats the IV catheters and all the internal tubing used for all the IV’s used all over the world every day as well. Silicone is the single active ingredient in Mylicon® (and in some 50+ similar products!) used for years to soothe intestinal gas or bloating problems in both children and adults. Silicone is used to coat the nipples and the liners used for the bottle feeding of infants. Silicone is used in the preparation of a wide variety of processed foods such as McDonald’s Chicken McNuggets and McDonald’s french fries. Silicone is also a very common ingredient used in many skin care products, antiperspirants, soaps, and chewing gum. Very important and widely used prosthetic implants – such as heart valves and artificial joints – rely upon medical grade silicone as a key component in both their construction and lubrication. And it is the feel and characteristics of the silicone in Silly Putty® that makes it such a perennial kid favorite!
The envelope shells (which are also made of silicone) of the first generation of silicone gel implants were thick and sturdy but nevertheless had what was known as a gel “bleed” phenomenon – an extremely slow, very difficult to detect, infinitesimal weeping of fine silicone droplets from the surface of the implant. This weeping of silicone material through the envelope shell could lead to the forming of granulomas, cysts and excessive scar capsule tissue around the implant (called a “capsular contracture”), making the breast feel overall hard and stiff. Since their inception, saline implants have never had any “bleed” problem – the salt water volume stays within the implant shell, completely and indefinitely, unless there is an actual leak or rupture.
It took 20 years, but by 1983 a superior silicone implant shell envelope had been perfected. It was thinner and softer for a better cosmetic look and feel but just as importantly, gel “bleed” was essentially eliminated. The granuloma/cyst rates and capsular contracture rates significantly decreased as expected accordingly.
In 1987, textured implant shell envelope surfaces were introduced. Independent and extensive research replicated at many centers over the next several years demonstrated that the textured surfaces significantly decreased capsular contracture and stiff scar rates even further. This was a significant advance for implant use in high risk for scar situations such as secondary breast reconstructions and revisions where the risk for capsular contracture problems is higher than normal.
Within the past 10 years another major technological advance was achieved for silicone gel implants. The internal gel was reformulated into what is called a cohesive gel. This has become known as the “gummy bear” implant. This type of gel sticks to itself almost as if it were a solid, soft rubber material. It does not “ooze” or flow when squeezed. The previous internal gel material was more like a toothpaste. A leak in the implant meant the “toothpaste” oozed out, dispersing free flowing liquid silicone, intermixing it in with the surrounding breast tissues. This posed a very challenging aspect to the replacing of a ruptured silicone gel implant. From a practical point of view it was often a quite difficult and time consuming surgery to remove all the dispersed silicone in order to limit future granuloma and scar tissue formation. Many times this necessitated the removal of some healthy tissue hopelessly intermingled with silicone. Fortunately, we do not have to contend with these issues with the cohesive gel “gummy bear” implants because modern silicone gel does not ‘flow”. Although soft, mushy and mobile, if a gummy bear implant were cut completely in half, each silicone gel “wall” on either half would stay completely in place. The consequences of a rupture or leak of a silicone gel implant are now quite minimal. Replacement is still needed once a leak has been identified and implant integrity has been lost, but it is a much, much simpler process.
Silicone gel implants do not pose any risk to the developing fetus during pregnancy nor is infant breast feeding a concern – there is no risk to the baby. In fact, there are higher levels of silicone detectable in cow’s milk and infant formulas over the barely detectable levels in breast milk in women with implants!
Extensive independent research has also confirmed that silicone gel breast implants have no connection to autoimmune (connective tissue) diseases and do not in any way alter or impair the functioning of the immune system. Silicone gel implants have never been implicated as a cause of breast cancer nor have they ever been demonstrated to even have any potential for causing breast cancer.
Anaplastic Large Cell Lymphoma (ALCL) is a very rare type of cancer of the blood cells and is a form of Non-Hodgkin’s Lymphoma. ALCL is so rare that it is difficult to detect trends or patterns as to its occurrence. But even more rare still is ALCL occurring in the breast (and it is not actually breast cancer). Recent intense research into ALCL going back over the records of some 25 + years revealed that nearly every diagnosed case of ALCL occurring in the breasts was seen in women with textured silicone gel breast implants. An extremely small but detectable incidence of 1 – 6 cases per 3 million breast augmentations was calculated. To give an idea of the level of rarity here, by comparison the odds of being struck by lightning in any given year is 4 -5 cases per 3 million in population. ALCL occurring in the breast appears to only form in the scar tissue (the capsule) around the implant, and not in the breast tissue itself. And ALCL seems to only be linked with the implant scar capsule surrounding a very specific type of breast implant – namely, the textured silicone gel breast implant. To date, ALCL does not appear to have any association with any other type of breast implant. ALCL does not appear to occur in patients with saline implants, nor does it seem to have any association with any type of silicone gel implant other than those with textured shells. The treatment for most patients with biopsy proven ALCL of the breast is removal of the affected scar tissue, i.e. the capsule, which essentially cures the problem. No mastectomy, no chemotherapy, and no radiation is typically needed.
What’s the bottom line? Given the wealth of solid research supporting their use as safe and effective, the consensus among plastic surgeons is that the FDA approval of silicone gel implants is appropriate. Silicone gel implants represent a safe, effective and reasonable option for the enhancement or reconstruction of the breast. But which is the better choice, silicone or saline? To learn about how to best arrive at the answer to that complex question, please check out our associated article, “Silicone vs. Saline Breast Implants – Which Is Better?”
