Breast augmentation


In medicine, breast augmentation or augmentation mammoplasty is a cosmetic surgery procedure that uses either a breast implant or a fat-graft to realise a mammoplasty to increase the size, change the shape, or alter the texture of the breasts, either as a cosmetic procedure or as correction of congenital defects of the breasts and the chest wall.
To augment the breast hemisphere, a breast implant filled with either saline solution or a silicone gel creates a spherical augmentation. The fat-graft transfer augments the size and corrects contour defects of the breast hemisphere with grafts of the adipocyte fat tissue, drawn from the body of the woman. In a breast reconstruction procedure, a tissue expander is emplaced and filled with saline solution to shape and enlarge the implant pocket to receive and accommodate the breast-implant prosthesis.
In most instances of fat-graft breast augmentation, the increase is of modest volume, usually only one bra cup size or less, which is thought to be the physiological limit allowed by the metabolism of the human body.

Surgical breast augmentation

Breast implants

There are four types of implants:
  1. Saline implants filled with sterile saline solution.
  2. Silicone implants filled with viscous silicone gel.
  3. Alternative-composition implants, filled with various fillers such as soy oil or polypropylene string.
  4. "Structured" implants using nested elastomer silicone shells with saline between the shells.

    Saline breast implant

The saline breast implant, filled with saline solution, was first manufactured by the Laboratoires Arion company, in France, and introduced for use as a prosthetic medical device in 1964. Modern-day versions of saline breast implants are manufactured with thicker, room-temperature vulcanized shells made of a silicone elastomer. The study In vitro Deflation of Pre-filled Saline Breast Implants reported that the rates of deflation of the pre-filled saline breast implant made it a second-choice prosthesis for "corrective breast surgery". Nonetheless, in the 1990s, the saline breast implant was mandated to be the prosthesis usual for breast augmentation surgery, the result of the U.S. Food and Drug Administration's temporary restriction against the importation of silicone-filled breast implants.
The technical goal of the saline-implant technique was a less-invasive surgical technique, by inserting an empty, rolled-up breast implant through a smaller surgical incision. In surgical practice, after having installed the empty breast implants in the implant pockets, the plastic surgeon would then fill each device with saline solution through a one-way valve and, because the required insertion incisions were short and small, the resultant incision scars would be smaller and shorter than the surgical scars typical of the pre-filled, silicone-gel implant surgical technique.
When compared with the results achieved with a silicone-gel breast implant, the saline implant can yield "good-to-excellent" results of increased breast size, a smoother hemisphere contour, and realistic consistency; yet it is likelier to cause cosmetic problems, such as the rippling and the wrinkling of the breast-envelope skin, and technical problems, such as the implant's presence being noticeable to the eye and to the touch. The occurrence of such cosmetic problems is likelier in the case of a person with very little breast tissue; in the case of a person who requires post-mastectomy breast reconstruction, the silicone-gel implant is the technically superior prosthetic device for breast reconstruction. In the case of a person with much breast tissue, for whom sub-muscular placement is the recommended surgical approach, saline breast implants can give an aesthetic result much like that produced by silicone breast implants: an appearance of proportionate breast size, smooth contour, and realistic consistency.

Silicone-gel breast implant

The modern prosthetic breast was invented in 1961, by the American plastic surgeons Thomas Cronin and Frank Gerow, and manufactured by the Dow Corning Corporation; in due course, the first augmentation mammoplasty was performed in 1962. There are five generations of medical device technology for the breast-implant models filled with silicone gel; each generation of breast prosthesis is defined by common model-manufacturing techniques.

First generation

The Cronin–Gerow implant, prosthesis model 1963, was a silicone rubber envelope-sack, shaped like a teardrop, which was filled with viscous silicone-gel. To reduce the rotation of the emplaced breast-implant upon the chest wall, the model 1963 prosthesis was affixed to the implant pocket with a fastener-patch, made of Dacron material, which was attached to the rear of the breast implant shell.

Second generation

In the 1970s, manufacturers offered the second generation of breast implant prostheses
  • The first developments were a thinner-gauge implant shell, and a filler gel of low-cohesion silicone, which made the devices more functional and realistic. Yet, in clinical practice, second-generation breast implants proved fragile, with greater rates of shell rupture and filler leakage through the "intact device's shell. The consequences, plus increased rates of capsular contracture, precipitated faulty product class action-lawsuits by the U.S. government against the Dow Corning Corporation and other manufacturers of breast prostheses.
  • The second technological development was a polyurethane foam coating for the shell of the implant; the coating reduced the degree of capsular contracture by causing an inflammatory reaction that impeded the formation of a capsule of fibrous collagen tissue around the coated device. Nevertheless, despite the intentions behind the polyurethane foam coating, the medical use of polyurethane-coated breast implants was briefly discontinued due to the potential health risk posed by 2,4-toluene diamine, a carcinogenic by-product of the chemical breakdown of the polyurethane foam coating of the breast implant. After reviewing the medical data, the FDA concluded that TDA-induced breast cancer was an infinitesimal health risk to anyone with breast implants, and did not justify legally requiring physicians to explain the matter to their patients. Ultimately, polyurethane-coated breast implants remain in plastic surgery practice in Europe and in South America; no manufacturer has sought FDA approval for medical sales of such breast implants in the U.S.
  • The third technological development was the double-lumen breast implant, a double-cavity prosthesis composed of a silicone breast implant contained within a saline breast implant. The two-fold, technical goal was: the cosmetic benefits of silicone gel enclosed in saline solution ; and a breast implant whose volume is post-operatively adjustable. Unfortunately, the more complex design of the double-lumen breast implant had a device-failure rate greater than that of single-lumen breast implants. This style of implant, in modern times, is primarily used for breast reconstruction.

    Third and fourth generations

In the 1980s, the third- and fourth-generation implants were stepwise advances in manufacturing technology, such as elastomer-coated shells that decreased gel bleed, and a thicker, increased-cohesion filler gel. The manufacturers of implantable breast prostheses then designed and made anatomic models and "shaped" models, which realistically corresponded with the breast and body types of actual women. The tapered models of breast implants have a uniformly textured surface, to reduce rotation of the prosthesis within the implant pocket; round models of breast implants are available in both smooth-surface and textured-surface models, as rotation is not an issue.

Fifth generation

Since the mid-1990s, the fifth generation of silicone gel breast implants is made of a semi-solid gel, which mostly eliminates the occurrences of filler leakage and of the migration of the silicone filler from the implant-pocket to other areas of the person's body. The studies Experience with Anatomical Soft Cohesive Silicone gel Prosthesis in Cosmetic and Reconstructive Breast Implant Surgery and Cohesive Silicone gel Breast Implants in Aesthetic and Reconstructive Breast Surgery reported relatively lower rates of capsular contracture and of device-shell rupture, and relatively greater rates of "medical safety" and "technical efficacy" than those of early-generation breast implants.

Alternative-composition implants

Saline and silicone gel are the most common types of breast implant used in the world today. Alternative-composition implants have largely been discontinued. These implants featured fillers such as soy oil and polypropylene string. Other discontinued materials include ox cartilage, Terylene "wool", ground rubber, silastic rubber, and Teflon-silicone prostheses.

"Structured" implants

Structured implants were approved by the FDA and Health Canada in 2014 as a fourth category of breast implant. These implants incorporate both saline and silicone gel implant technology. The filler is saline solution, in case of rupture, and has a natural feel, like silicone gel implants. This implant type uses an internal structure consisting of three nested silicone rubber "shells" that support the upper half of the breast, with the two spaces between the three shells filled with saline. The implant is inserted, empty, then filled once in place, which requires a smaller incision than a pre-filled implant.

Implants and breastfeeding

The breasts are apocrine glands which produce milk for the feeding of infant children,

Breast implant toxicity

Digestive tract contamination and systemic toxicity due to the leakage of breast implant filler to the breast milk are the principal infant health concerns with breast implants. Breast implant fillers are biologically inert: silicone filler is indigestible and saline filler is mostly salt and water. Each of these substances should be chemically inert and present in the environment. Moreover, "proponent" physicians have stated that there "should be no absolute contraindication to breast-feeding by women with silicone breast implants." In the early 1990s, at the beginning of the silicone gel breast implant illness panic, small-scale, non-randomized studies indicated possible breast-feeding complications from silicone implants; no one study was able to demonstrate disease causality due to implants.