How could it happen? Why are questions about the safety of silicon breast implants coming to light now, after they have been used by more than a million women over the past 30 years?
The simple explanation is that silicon breast implants were never required by the Food and Drug Administration to undergo rigorous scientific study before use in human patients.
Silicon breast implants are one example of thousands of devices and materials routinely used in medicine that have never been subjected to mandatory safety testing.
Until relatively recently, the FDA took its name quite literally. Its mission was to assure the safety and purity of foods and drugs. The FDA had no jurisdiction over medical materials or devices until 1976, when a law was enacted to include them in the agency's charter.
But manufacturers were left a huge loophole. Conducting tests of the countless thousands of medical products already on the market would have cost industry hundreds of millions of dollars. A grandfather clause -- called 510-K -- permits manufacturers to sell products that are "substantially equivalent" to those marketed before the 1976 law went into effect.
"A large percentage of the devices in use today are 510-K," says Harold Alexander, editor of the Journal of Applied Biomaterials.
Materials falling within 510-K "have not gone through the full [FDA approval] process," Dr. Alexander says. "If a manufacturer can show that a device existed or is substantially equivalent to a device that existed before 1976, then they don't have to go through a lot of extensive laboratory tests, animal tests, and clinical trials."
Manufacturers make use of the loophole to introduce a product much sooner and at considerably less cost than they would otherwise.
"If the material has been widely used clinically, the FDA does not ask you all these questions about safety," says Bethesda consultant Nasser Salmon, who helps industry clients get products through the FDA approval process.
Surgeons can use unregulated medical devices, or even stuff purchased in a department store. There are no laws to prevent surgeons from using unorthodox materials. There is no agency that makes sure patients aren't placed at risk.
"We don't regulate the practice of medicine by a person who is licensed to do so," says FDA spokesman Mark Bartlett. "If a doctor does something that is not the standard of care, then he may be subject to litigation from the patient or sanctions from the hospital or local medical society. But as far as the FDA saying they can't do it, that usually isn't the case."
The use of unregulated material is quite common, says Jacob S. Hanker, chief of biomaterials at the University of North Carolina, Chapel Hill. "A couple things I'm working with right now are just ready for FDA approval, but they're being used daily on humans now," he says.
Consider the case of Krazy Glue, the amazing one-drop-holds-a-ton adhesive. Also known by its chemical name, cyanoacrylate, Krazy Glue has never been approved by the FDA. Still, many surgeons find the adhesive useful for a wide range of applications.
Krazy Glue is used instead of sutures to close skin wounds. It can patch an aneurysm, a weakened section of a blood vessel. It can be injected into the blood stream to shut off circulation to a tumor, shrinking its size so it can be surgically removed.
The adhesive "can be used just about any time something small needs to be held together real good," says Ron Hubbard, an ear, nose and throat surgeon in Memphis, Tenn.
But some experts say Krazy Glue can be dangerous. Studies show that the adhesive can cause inflammation, even tissue death. "Krazy Glue can cause some pretty severe reactions," says Dean Toriumi, facial plastic and reconstructive surgeon at the University of Illinois at Chicago.
Even so, Krazy Glue is "being used all over the place," according to Temple University ear, nose and throat surgeon Max Ronis. In 1984, he surveyed 115 academic medical centers to learn how widely Krazy Glue is used. More than a third of those who responded to his survey admitted a "current working knowledge" of the adhesive and others like it.
"There is still an active interest in these adhesives despite the absence of Food and Drug Administration approval," Dr. Ronis wrote in the journal Laryngoscope.
While special cyanoacrylate compounds made specifically for surgery are available, many surgeons use the same Krazy Glue sold in hardware stores.
"If a surgeon uses it once and doesn't have any problems, he may use it in another 20 patients," says Dr. Toriumi. "Even though you use it in a patient and there isn't any problem, that doesn't mean that there isn't something going on under the skin where nobody can see it."
Harlan Stone, a former University of Maryland surgeon, uses zippers to close the abdomen of patients who have surgery of the pancreas.