The number of women in the United States who have breast implants is unknown, but current estimates derived from national surveys of up to 4 million +. This is more than 3% of the adult female population. It is estimated that 70-80% of breast implant procedures were performed for cosmetic and 20-30% for the reconstruction of congenital anomalies or defects post mastectomy. Following the adverse publicity in the early 1990, interest in the procedure was reduced by almost 50%, but seems to have recovered gradually. In 1998, approximately 350000 pairs were sold in the United States for the increase.
Before 1963, various plastic foam materials were used, however, it became apparent that the air would collapse and cells, combined with tissue in growth, reduce and tighten the device. These materials were wrapped in plastic to minimize this effect was in vain. Surprisingly, some of these implants were well tolerated who have remained in place until today.
The modern silicone breast implants has been available since 1963 and has gone through an evolution of change and improvement. Several types of devices, with many variations and styles within each class have been created. Basic for all silicone implants is a rubber (rubber) shell, which may be single or double, smooth or textured, coated barrier, or covered with polyurethane foam.
The contents are either factory filled with silicone gel of different consistencies or inflated to surgery with normal saline. A brand manufactured abroad was briefly marketed in the United States and was pre saline in the factory. This device was withdrawn later when the FDA denied approval.
The dual lumen devices consist of concentric balloons containing silicone in one house and saline in the other. The only one still in use is Becker, who has an outer layer of gel inside and a ball valve that is to allow inflation postoperative gradually with saline solution. This is called a "permanent tissue expander", as it allows gradual and temporary over inflation to create the pocket, then you can leave a permanent implants after the size fits properly.
The gel implants
Three generations of basic design of this device have been created, with many variations within each type.
First generation
The first models that are marketed have thick envelopes, smooth wall silicone elastomer made in 2 sections, filled with silicone gel viscous material, and stick together. In the early years, researchers believed that the device requires adherence to the tissues to prevent migration. Scar in growth for fixing was conducted by patches of material, such as Dacron mesh or perforated silicone, which is attached to the back of the device or by an outer covering of polyurethane foam. The Dacron patches and silicone were subsequently found to be unnecessary and, indeed, remained in the quality of the result. Some patches or tabs created a point of tension that led to tears of the envelope. Fixing patches have been eliminated in the early 1970's.
Second generation
Evolution brought changes in the gel consistency and thickness shell in an attempt to improve performance. Since the mid-1970, the shells were thinner and less viscous gel (ie more "sensitive"), especially in an ill-conceived attempt to control capsular contracture. This trend was reversed in the early 1980's to realize that it is not effective in reducing the contracture and resulted in a more fragile. Most were broken 10 years later.
Third generation
New formulations of the shell before it was to be strong and significantly lower "bleed" or dissemination is usually small amounts of silicone oil fraction of the gel content. The gel content also became more viscous and cohesive.
In 1989, with the surface texture of envelopes that many surgeons are expected to minimize the incidence of unwanted firmness of capsular contracture were available. Recent studies are somewhat confused about whether this is effective. They are also available with removable devices subcutaneous fill ports, which allow the adjustment of postsurgical size. The texture devices seem to have a higher rupture rate than those with good shells.
Polyurethane-covered implants
In the late 1960's, a variation of the device has been developed that contains a coating of polyurethane through an otherwise standard gel-filled implant. Despite the fact that the coating was originally planned as a layer of fixing, more surgeons came to believe that the foam pad resulted in a decreased incidence (or at least delay the onset) of capsular contracture. These implants also evolved in shape and design, which culminated in the 1980's with the Meme Optimam and styles. Zhengzhou Zd Valve In April 1991, the manufacturer withdrew voluntarily covered foam implants market.
A style, MemeME had a unique construction. There was a shell but a type of skin was formed in situ by spraying the surface with silicone that contain extra catalyst before cure. This increase in cross linking the area to create a shell-like membrane. Without the filling of silica, this membrane is not as strong as a shell. The polyurethane foam is formed and stamped by the surface. Implants of this type are known to occasionally stretched some of its content through gel foam when squeezed. This is one possible explanation for reports of blood that are at the bottom of the gel implants apparently intact. The MemeME model was marketed from 1983-1988.
Although silicone remained the only material available shell, the new filler substances were in use in Europe and South America, while under development or in pilot testing in the United States. Several hydrogels and a pure form of triglycerides are the main 2 formulations. The main advantage of the formulation of triglycerides (Trilucent) was that he had a number Z (far radiolucency) similar to that of fat, so that little or no commitment to mammography. Another filling substance, policloruro of pyrrolidone in saline, was briefly available in the United States under the trade name Misty Gold. None of these products are currently available in the United States. All currently considered Gate Valve fill substances are designed to be absorbed and excreted aggressive if the shell cracks or leaks. Apart from time-honoured silicone gel-filled nonabsorbable is currently unavailable in this country.
Documents submitted in clinical trials is a new formulation of gel padding that is thicker and more coherent in order to minimize the spread gel in the case of rupture.
As evidenced by the sales figures before the moratorium, approximately 80-85% of surgeons and patients prefer the quality of the results obtained by gel implants. Gel devices appear to be the choice of implants for use post mastectomy. In 1997, sales figures for Europe, where use is free, show an allocation of 70% gel, 15% saline, and 15% of alternate fills as triglycerides (then still available) and hydrogels for cosmetic use.
As of this writing, owing to restrictions imposed on the sale of the gel device from the FDA, these implants are only available for the rebuilding or replacement under a strict protocol. The FDA recently concluded hearings in which the latest safety data on the gel implants were submitted by both manufacturers. The panel approved the corporation Mentor devices for cosmetic purposes under strict regulation and monitoring of needs but denied approval for the product Inamed. The panel recommendations are only advisory, and it remains to be seen whether the FDA accepts his advice or, as they have done before, continue to ban the cosmetic use.
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