The Silicone Breast Implant Controversy

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There has been a great deal of controversy regarding the safety of silicone breast implants. For the women who have implants, conflicting media reports can be a source of considerable stress. As a plastic surgeon performing breast surgery for over twenty years and a woman who has had silicone gel breast implants from 1985 to 1997, I hope to help inform women regarding this topic.



There are still many unanswered questions regarding the safety of silicone breast implants. Studies are ongoing, but results may not be available for several years. Education may help relieve some of the anxieties until results become available.



Silicone implants are silicone shells filled with either saline (salt water) or silicone gel, or a combination of the two. Some silicone gel implants are coated with a polyurethane material and are called Natural-Y implants.



Silicone breast implant complications can be divided into two categories: local chest wall complications and more generalized “systemic” problems. Local complications include capsular contracture, or the tightening of scar capsule around the implant, malposition and rupture and/or leakage of the implant.



Capsular contractures can cause local discomfort and upward displacement of the implant. Capsular contractures are believed to be the result of a low-grade infection around the implant. The low-grade infection causes tightening of the normal scar around the implant and as the implant is squeezed, it appears more firm. Capsular contractures are more common when the implants are placed behind the breast tissue and in front of the chest wall muscles. This is felt to be due to the contamination of the implant from breast ducts, which normally contain some bacteria. If the implants are placed behind the chest wall muscles and the surgeon avoids cutting through the breast tissue, the incidence of capsular contractures is reduced. Irrigation of the surgical area with antibiotics has also been shown to reduce the risk of capsular contracture.



Malposition of the implant is usually due to capsular contracture. When the scar tissue tightens, the implant tends to ride up on the chest wall. Malposition can also be due to steroids placed in the pocket or saline implant during surgery. Steroids can thin tissue, leading to a gradual downward migration of the implant.



Rupture of the implant occurs when the silicone shell has a hole or tear, which allows the migration of the contents outside the shell. Saline is reabsorbed without difficulty but silicone gel is not as easily disposed of by the body. In most cases, the scar capsule around the implant contains the majority of the silicone gel. Leakage occurs when silicone “bleeds” through the silicone shell. The idea that microscopic silicone has spread throughout the body has been a source of concern for many women with ruptured and/or leaking implants. For women who have migration of larger amounts of silicone gel outside of the scar capsule, the surgical removal of this material is more difficult. Again, however, the body tends to isolate the offending material with scar and other tissue designed to contain foreign material within the body.



Fortunately, the majority of ruptures of silicone gel implants occur inside and are grossly contained by the scar capsule. Surgical removal of the scar capsule and ruptured implant is much easier if the silicone has not migrated into tissues outside of the scar capsule. It is important that the explanting surgeon use a technique that minimizes the risk of free silicone coming into contact with tissues and that all of the scar capsule be removed, as it contains silicone particles in the majority of cases.



Pathological examination of the scar capsules surrounding the silicone gel implants often show macrophages filled with vaculated or foamy material. The macrophages are the body’s scavenger cells, which attempt to ingest any material that the body regards as foreign. Most silicone gel implants, especially those manufactured prior to 1985, were known to have small amounts of silicone gel “bleed” or leakage through this silicone shell. The breast implant manufacturers were aware of these phenomena and, in the early 1980’s, Dow Corning developed a “low bleed” gel implant, which had a different silicone shell that was less likely to have silicone gel bleed. We assume that the silicone gel bleed occurs to some extent in all silicone gel implants and this accounts for the foamy material found in the macrophages in the scar capsule. Even in patients with unruptured implants, we assume that some silicone gel travels beyond the shell of the implant.



The early silicone gel implants developed by Cronin had fairly thick silicone shells. These had a tendency to form capsular contractures and often had calcium deposits within the scar capsules. The tendency for implants to rupture increased when companies developed a thinner, more pliable silicone shell. The thinner shell, developed in 1969, was widely used until the development of the low bleed implant in 1984. Further improvements in the silicone shell occurred in 1990, when a textured silicone shell was developed which was not only more resilient but was felt to reduce the incidence of capsular contracture.



Currently, plastic surgeons are able to choose between two types of saline implants. The smooth wall saline filled implants are felt to have fewer problems with wrinkling, and the textured saline filled implants are felt to have a lower incidence of capsular contracture. Because the saline implants are a different (lighter) density than silicone gel implants, they tend to feel “sloshy” or less natural than silicone gel implants, especially if the woma