BETHESDA -- In a surprising new wrinkle in the debate over silicone breast implants, a Dow Corning official said yesterday that the company might welcome a prolonged moratorium on their wide-scale use if it were allowed to test their safety on a limited number of women.
Dow, the country's leading implant manufacturer, insisted that any serious illnesses suffered by implant patients would have happened anyway. But Dow officials admitted at the same time that there haven't been any large-scale human studies that either implicate or exonerate the implants. They proposed four years of studies to settle the controversy.
Testifying before the Food and Drug Administration's advisory panel yesterday, Dow scientist Robert LeVier proposed a system that would allow women to get the implants if they enroll in clinical trials. A network of doctors across the country would participate, and they would carefully track their patients to see if their illness rates differ from the general population.
"We're not proposing free and open sales to all," said Dr. LeVier, technical director of Dow Corning's health care businesses, after his appearance before the panel. "We think the product does what it's supposed to do. It's safe, and we know women want it. We propose they be able to have it, and we collect the data."
He said the trials would involve thousands of women, but far fewer than the 130,000 women a year who got the implants before FDA Commissioner David Kessler requested a moratorium last Jan. 6 to give experts a "timeout" to review their safety.
Besides tracking the health of women who receive new implants, Dow proposed a look-back study into the health of thousands of women who have received implants in the last three decades.
The advisory panel is scheduled to conclude its three-day hearing today and issue its advice to Dr. Kessler. It could recommend that he ban the implants, allow their unfettered sale or permit their use with certain restrictions.
On Tuesday, two radiologists said that the devices ruptured in 5 percent to 6 percent of several hundred women they screened with mammography. They said most of the breaks were "silent ruptures" -- ones that the women could not feel or see.
And four physicians told of scores of implant patients who suffered from autoimmune diseases like rheumatoid arthritis and lupus.
They also described some patients who came down with chronic fatigue, gangrene and Lou Gehrig's disease.
But representatives of the four companies that manufacturer the silicone bags said there was no evidence proving that leaking or rupturing silicone caused the illnesses. While the diseases are rare, they said thousands of women every year can be expected to get them whether or not they have implants.
They also disputed the reports of high rupture rates, saying their studies have shown that well under 1 percent of all implants have broken.
A plastic surgeon said the amount of silicone that seeps through the walls of intact implants is tiny -- equal to the amount in a common antacid.
One of the day's most tense exchanges came after Dr. Norman Cole, president of the American Society of Plastic and Reconstructive Surgery, said he supported the idea of a registry that would allow doctors to track the health of all implant patients.
Dr. Norman Anderson, a non-voting panel member from the Johns Hopkins School of Medicine, said that was fine but he was outraged that the society had reneged on past agreements to do just that.
"The public and the FDA have waited three decades for the society's contributions to resolve these questions," said Dr. Anderson, an internist who was stripped of his vote last week after saying publicly that he wanted the implants banned.
He suggested that the surgeon's organization divert money from its political action committee to pay the medical expenses of women who want their implants removed.
Dr. Cole didn't agree to the use of political funds, but said he expected a network of plastic surgeons would "provide the needs" of such women who couldn't afford the cost.
The basic styles
Silicone breast implants, which are made by Dow Corning Corp. and three other manufacturers, generally consist of a seamless bag or "shell" of stiff, rubbery silicone that is filled with silicone gel.
Implants come in five basic styles, according to Jerry Kuester, a researcher with the National Women's Health Network in Washington.
* A silicone shell filled with silicone gel.
* A silicone shell filled with saline solution.
* A "double lumen" device, which consists of a silicone shell-within-a-shell, with silicone gel filling the inner shell and the space between the inner and outer shell.
* A double lumen in which the inner shell is filled with silicone gel and the outer with saline solution.
* A silicone shell that is inflatable, meaning that saline can be injected in stages.
The devices come in a variety of shapes, including a teardrop, half-grapefruit and hamburger patty.
Many plastic surgeons prefer the silicone gel implants to those filled with a saline -- or salt water -- solution because saline implants can't be shaped to the extent that silicone implants can, creating a less natural-looking breast. Some women find that saline devices do not feel as much like living tissue as silicone implants.
Before the most recent discussion of implant safety began, the biggest concern of many physicians was the potential for the implants to hide tumors during mammography, reducing chances of detecting breast cancer. In some cases, there is also painful hardening of the scar tissue around the implant.
More recently, concern about the implants has focused on leakage of silicone gel from the shell due to rupture or "bleeding" through pores in the shell material. Once that happens, silicone lumps can form in the body.
At least two national hot lines have been set up for people with questions about breast implants:
* The American Society of Plastic and Reconstructive Surgeons: 1-800-945-6380.
* The Food and Drug Administration: 1-800-532-4440.