HOUSTON — The career of Thomas Biggs, M.D., is as entwined with the modern evolution of breast implants as are the staff and snakes of the caduceus. He trained under Thomas Cronin, M.D., who — along with Frank Gerow, M.D. — was responsible for developing the first modern-day silicone gel breast implant in conjunction with Dow Corning.

Since then, he has been involved in more than 8,000 breast implant procedures throughout a career that has spanned more than 40 years. Today, the semi-retired Baylor College of Medicine clinical professor of plastic surgery travels the world lecturing about the evolution of breast implants and performing surgery in far-flung locales, from Brazil to India and everywhere in between.

Dr. Biggs' primary message when lecturing about breast implants is that "They are not a way to get a boyfriend back or to keep a husband interested. The breast is the external symbol of a woman's gender, so anything that we can do to make the breast more appealing to a woman enhances her feeling of her own womanhood and gives her more self-assurance." This, he says, is what he told his audience back in 2000 when he was among a hand-picked group of physicians who were invited to the Vatican to discuss their medical specialty.

IN THE BEGINNING While the history of modern breast implants starts with Dr. Biggs' colleagues Dr. Cronin and Dr. Gerow, attempts to enhance the size and/or shape of the breast weren't new — efforts were made even in the 1890s. "Early attempts ranged from very, very bad to not good, and they all failed," Dr. Biggs says.

The implants that immediately preceded Dr. Cronin's and Dr. Gerow's "natural feel" implants included sponge prosthetics made of Etheron (polyether foam sponge), Polystan (polyethylene tape) and polyethylene. Within a year, all of these resulted in capsular contraction, which collapsed the sponge and deflated the implants by 25 percent or more. "Then," Dr. Biggs says, "in 1962, Cronin and Gerow created an implant made out of silicone."

The inspiration for the early silicone gel implant was a blood transfusion bag. Early blood transfusion vessels were made of glass. During the silicone gel implant's developmental stages, Dr. Cronin visited a blood bank, and upon feeling the new and improved flexible plastic bag that contained the blood, he observed that it felt like a breast, according to Dr. Biggs. The rest, as they say, is history.

Silicone was used to make a thin, flexible "fabric bag," and also to make a gel-like substance with which to fill it. "The cohesiveness of the gel could be altered so that it could be very thin or even solid," Dr. Biggs says. "They created one small implant and put it into a dog and the dog was fine, so then they implanted it in a person and she got along just great. So then we began to put it into more and more people," he says, noting that "In those days, there was very little regulation, so there was minimal obstruction to its being manufactured and sold."

Dr. Biggs recalls that Dr. Cronin and Dr. Gerow thought the implant had a great future, because it was virtually nonreactive. Dr. Biggs and his colleagues encountered a multiplicity of problems throughout the developmental phase, but, ironically, the only one that persisted — and resulted in almost every early case — was fibrous capsular contraction.

"The body needs to isolate a foreign material from itself, and the wall that built up around the implant would contract and make the implant feel hard. One of the things that we did to minimize this problem was to coat the implant with polyurethane. Once we did this, the incidence of capsular contraction dropped to almost zero," he says.