Breast ImagingBreast implant
device used for augmentation and reconstruction of the breast. Implants can be classified according to:
1. Shell material (silicone, elastomer, polyurethane)
2. Shell surface (smooth, textured)
3. Filling material (silicone gel, saline, polyvinylpyrrolidone (PVP), dextran, soybean oil)
4. Fixed or adjustable volume (permanent or temporary, expander/expander implants)
5. Shape (round, low/intermediate/high profile, tear drop, "natural Y", "anatomic", contoured, etc.)
6. Single lumen/double lumen/reverse double lumen
1. The silicone shell is practically the only one used today. Polyurethane was abandoned in the USA when animal studies showed an increased frequency of liver sarcomas in mice from one of the degradation products of polyurethane (TDA).
2. Capsular contracture is the most common side effect of smooth breast implants. Capsular contracture occurs much less frequently around textured implants.
3. Saline has become the most commonly used filler material, because of US legal activities since the temporary moratorium on silicone gel in January 1992. For breast augmentation gel is not available in the US except in strictly controlled clinical studies. However, for breast reconstruction the restrictions are less limiting. Silicone gel has a more breast-like consistency than saline. Soybean oil-filled implants are also available today. Their main advantage is their radiolucency, equal to that of fat, which does not hamper mammography. Unfortunately, the consistency of the soybean oil-filled implants is more like the saline than the gel-filled implants.
4. Implants with adjustable volume may have filling valves directly on the implant surface or a fill tube connected to a distant port. Tubes and ports are removable in many implants (Fig.1).
5. Lots of different shapes and sizes are available on the market to meet the various anatomical needs of patients needing breast reconstruction and augmentation.
6. Double lumen implants have an inner silicone gel compartment and an outer saline lumen or the reverse.
Also, see breast implant failure and Capsular contracture.
AR