In 1961, US surgeons Thomas Cronin, Frank Gerow and Dow Corning developed the first silicone breast prosthesis filled with viscous liquid silicone gel, and performed the first breast augmentation in 1962 using their 1963 model. In 1964, French surgeon H.G. Arion and Laboratoires Arion developed the first saline-filled breast implant inside a silicone shell.
Saline filled implants gave an acceptable cosmetic result, but had problems with leakage and deflation, rippling and wrinkling especially in thinner woman, accelerated lower pole stretch with implant descent, and implant visibility and palpability. The silicone gel filled implant was technically superior and dominated through the 1970s and 1980s. In the 1990s however, in Australia, US and France, especially, only saline -filled implants could be surgically implanted due to the banning of the silicone liquid gel breast implants.
Silicone Gel filled Implants
With the arrival of cohesive silicone gel-filled breast implants in the mid 1990s, most surgeons used the technically superior cohesive silicone gel implants rather than saline -filled implants. Silicone gel-filled implants have gone through 5 generations in terms of technological development since the first generation Dow Corning implants, which had a smooth silicone rubber teardrop-shaped envelope filled with viscous liquid silicone gel and a Dacron patch on the back to stop rotation of the implant. Second generation implants experimented with thinner envelopes to feel more natural but with higher leak rates, Polyurethane coated textured-surfaced implants to reduce capsule formation which got banned over concerns about carcinogenesis, later shown to be unfounded, and adjustable double cavity implants, which had a very high device failure rate. Third and fourth generation silicone gel breast implants largely solved a lot of the early problems. The development of elastomer coated shells which decreased silicone gel bleed through the envelope, increasingly cohesive silicone gel fill, which reduced the risk of gel migration, a large range of round and teardrop shaped implants and the development of a textured surface to reduce the incidence of implant rotation and capsule formation. Fifth generation silicone gel implants saw the development of a semi-solid form stable high cohesive silicone gel fill.
Saline or silicone gel-filled implants can have a smooth or textured silicone elastomer surface as well as a Polyurethane coated surface. The smooth surfaced implant is the easiest to insert through the smallest incision. This makes it the preferred surface for some surgeons especially if they are using the trans-areolar or through the-nipple approach where the length of incision is limited. Because of the very high rate of hardening from capsular contracture, a giant pocket technique is used to limit capsule formation and the implants need to be regularly massaged and moved around the pocket to keep it open. Sometimes the smooth-surfaced implant may be useful in some patients with intractable rippling. All smooth surfaced implants are round.
Textured-surfaced implants have a much lower capsular contracture rate as the actual surface area of the breast implant (and therefore the mirror imaged capsule created by the body attaching to it) is many times greater than if it were smooth. Because they attach, the textured surfaced implants do not rotate. All shaped breast implants have a textured silicone elastomer surface to minimise the risk of rotation.
Polyurethane coated Textured Surfaced Implants
Polyurethane foam coated textured-surfaced breast implants were designed in the 1980s to reduce the very high rate of capsular contracture seen with smooth-surfaced implants by causing inflammation and delaying capsule formation. However, concerns raised regarding the possible risk of cancer caused by breakdown compounds saw them discontinued in the US and Australia. They continued to be popular in South America and Europe. After careful review, the US FDA concluded the risk of cancer to be so small that it didn’t justify a ban. Polyurethane coated textured surfaced breast implants have reappeared in Australia recently and are used by me in specific circumstances especially in the rare situation of recurrent capsular contracture. Nevertheless, even though these implants have a lower capsular contracture rate, it is still not zero.