2 Breast Implants
The major purpose of breast implants is to enhance or restore the appearance of the female breast. Women may have widely differing motivations for wishing to undergo cosmetic breast surgery. Each individual woman has own private sense of how she wishes to look and whether she wishes to go through surgery to achieve this appearance. Some women’s breasts become smaller after pregnancy and they want their breasts to be fuller again; others feel that their breasts are too small, poorly formed, or are disproportionate to their overall body size. Implants offer a viable and effective solution to these problems.
A number of studies have been carried out to assess patient satisfaction after breast implant operations. The results have consistently shown that more than 60 %, and in some reports as many as 80–90 % of women who have had implant surgery for augmentation, are pleased with the results of the procedure, even if they were less than ideal or were associated with complications.
Even more important are silicone breast implants for breast reconstruction after mastectomy. Women who have had implants for breast reconstruction report that they no longer feel deformed as they did following mastectomy, and that they feel more normal and less depressed about their appearance. They also report that breast reconstruction with breast implants aided their recovery from breast cancer and reduced emotional stress by helping to restore the body to a more natural appearance, as opposed to having nothing done or using an external prosthesis.
In comparison with other possible surgical treatments (such as flap reconstruction), breast implants are associated with fewer surgical complications, require less surgical procedure time, are less costly, and are followed by a shorter recovery period.
All of the implants currently on the market consist of a silicone shell and various filler substances such as silicone gel, saline, and hydrogel.
Silicone gel implants in particular have advanced considerably since they were first introduced in the 1960s. They are therefore also the most widely used type of implant. Silicone gel implants are available in a variety of sizes and now also come in a wide variety of anatomical shapes. This means that treatment can be tailored to the individual patient, whether for augmentation or reconstruction. The use of highly polymerized gel is also becoming more common in silicone implants. This helps prevent leakage (of liquid silicone) if the shell is damaged. Another advantage is the natural feel of silicone gel, which closely resembles that of breast tissue. Silicone implants are much softer and more pliable than saline implants, in particular.
The main disadvantage of saline implants is their firmer feel. Although anatomically shaped saline implants are now available, their shape is not as stable as that of silicone gel implants. Saline implants are usually filled at the time of surgery, and this can lead to problems. Underfilling can result in damage to the implant caused by the implant walls rubbing against each other. Conversely, overfilling results in an implant that feels too firm. Despite improvements in design, volume loss continues to be a problem (with spontaneous deflation of 1–5% per year). The major advantage of saline is that if the implant is damaged, the contents that are released are harmless.
Hydrogel implants are comparable to silicone gel implants in terms of having a natural feel. However, they have a greater specific weight and are thus somewhat heavier. In addition, only round implants are currently available. It is important for equilibrium with the bodily fluids adjacent to the implant to be maintained, as osmosis can otherwise produce volume fluctuations. However, this should no longer be a problem with the hydrogel implants now available. Nevertheless, if the implant ruptures, cleavage of the hydrogel and a corresponding increase in osmosis can lead to an uncontrolled increase in volume. According to the implant manufacturers, hydrogel itself is completely biodegradable.
Risks and Complications
The general risks and complications associated with breast surgery also apply to implant surgery. These include infection, hematoma or seroma formation, and delayed wound healing.
Specific complications related to foreign-body reactions can also occur irrespective of the implant type. The most common are implant infection and capsular contracture. Implant defects, displacement, and impaired mammographic screening are also problems.
Implant defects were more common with the older, second-generation models that were manufactured between 1970 and 1980. These were designed with a thin shell and a low cross-linked gel to give them a more natural appearance. As the implants aged, however, the shell developed a greater tendency to rupture. Nevertheless, silicone leakage was normally prevented by the surrounding tissue capsule formed by the body’s response to the implant.
Inadvertent damage to the capsule—during a manual capsulotomy, for instance—can lead to leakage of silicone into the surrounding tissues, often resulting in local foreign-body granulomas that are palpable as hard lumps. In the worst case, liquid silicone can migrate directly or through the lymphatic vessels into the surrounding glandular soft tissue, the pectoralis muscle, and the axillary lymph nodes. Careful surgical management is indicated, although absorption of the silicone gel is not a health risk in itself.
The diffusion of minimal amounts of potentially unpolymerized silicone is referred to as silicone “bleeding.” In addition to microscopic detection of silicone in parts of the capsule, silicone particles could also theoretically collect in other parts of the body. There is no evidence of a health hazard, however; the element silicon is present in minute amounts in every living organism.
Implants of the current generation have much more stable shells and almost all of them now contain highly polymerized (firm) gel, so that these concerns now appear to have been superseded.
Saline implants can deflate spontaneously. The exact mechanism is unknown. Deflation may be caused by a defect in the implant (e. g., damage to the valve or shell), or by loss of volume due to osmosis.