A new investigation by a consumer group has found that many widely used medical devices have never been tested for safety and manufacturers are only required to file paperwork and pay a small fee before bringing their products to market.
"The regulation of medical devices has been pieced together over the years," said Lisa McGiffert, director of Consumer Union's Safe Patient Project.
The patchwork approach has meant the only safety testing for many devices occurs in the bodies of unwitting patients, McGiffert said. She and other consumer advocates are calling on the Food and Drug Administration to revamp the way it approves medical devices.
Thousands of women, for example, have been implanted with transvaginal mesh for bladder support when the organ sags, but the commonly used device has never undergone clinical testing, according to the organization, Consumers Union of Yonkers, which publishes Consumer Reports magazine.
Many adverse side effects linked to the mesh have been reported, the group found.
It also notes 650,000 Lap-Band weight-loss devices, which limit the amount dieters consume, have been sold worldwide, but the Lap-Band's approval was based on a single study of 299 people.
Despite requirements for pre-marketing review, the investigation found few devices undergo rigorous clinical testing and the standards themselves haven't changed in a generation.
Diana Zuckerman, who heads the National Research Center for Women and Families, a Washington, D.C.-based consumer advocacy organization, told Newsday last year most medical devices are never tested on humans.
Worse, some devices recalled for posing life-threatening risks, she added, were approved through an expedited process or were exempt from review.
Wednesday, Zuckerman -- who applauded Consumers Union's research -- said most people have no idea medical devices are not held to the same strict scientific testing standards as prescription drugs.
"This is a huge problem," Zuckerman said. "It is a terrible state of affairs when someone is going to get a heart valve or a hip replacement and they don't know if it has ever been tested in a human being."
Consumers Union found, for example, that an artificial hip called the ASR XL developed by DePuy, a division of Johnson & Johnson, not only was ineffective for walking, but leached chromium and cobalt particles into patients' blood.
The metal-on-metal ball and socket was touted as an advance over other types of implants. DePuy has since recalled them.
Since 1976, medical devices have been divided into three classes: I, II and III.
Under FDA law, extensive agency review and pre-marketing approval are required for high-risk class III devices, such as implantable heart valves, intraocular lenses and stair-climbing wheelchairs.
Limited review is required for class II devices, including magnetic resonance imaging devices, hard contact lenses and battery-powered wheelchairs. None is necessary for most class I devices, such as tongue depressors and manual wheelchairs.
McGiffert said a major problem with the approval process is that many complex devices are automatically given a green light when a similar product is already on the market.