The majority of medical devices implanted into patients' bodies have never been tested by the FDA, according to a stunning report from the consumer advocacy magazine Consumer Reports.

The report stated that while tens of millions of Americans live with some form of medical implant in their body, few of these devices are subjected to rigorous testing. Under current FDA policy, medical device manufacturers are able to "grandfather in" new devices if they are "substantially equivalent" to a device that is already in use.

Rita Redberg, M.D., a professor of medicine at the University of California, San Francisco, said that this sets up an ironic paradox. “The paradox is that companies go to the FDA and claim that a device is ‘substantially equivalent,’ but when they market it, they claim it’s ‘new and better.’”

Such has been the case with surgical transvaginal mesh of the kind that was used to restructure the pelvis and bladder of 54-year-old Janet Holt of Floresville, Texas, one of the three victims of faulty medical devices whose stories are detailed in Consumer Reports. Hold was told by her gynecologist that a procedure involving surgical mesh would reverse her bladder and uterine prolapse.

Once it was inside her body, the mesh shrank and shifted. Holt was in so much pain she couldn't stand, sit or walk. Then the mesh began to protrude through her vaginal wall, a sensation she likened to "open cigarette burns with each step you take. It’s complete torture.”

Five years and eight corrective surgeries later, Holt continues to struggle with after-effects of the faulty mesh, which is still on the market in spite of thousands of complaints. The synthetic mesh was never tested on humans, but made it through the approval process because it was "substantially equivalent" to a type of mesh used since the 1950s for abdominal hernia repair, but never tested for pelvic or uterine restructuring.

The Lap-Band gastric band marketed by the company Allergan was also rushed to market without adequate testing, but by a different route. The bands were different enough from any previous devices that they couldn't be grandfathered in, but the testing protocols for surgical devices aren't nearly as rigorous as the requirements for new drugs.

To even apply for testing for a new drug, the FDA charges $1.84 million. -- but the FDA only requires $220,050 to test a new device. The single test study for Allergan's Lap-Band only consisted of 299 patients over a three year period. Around 51 percent of those people experienced nausea and vomiting and a full quarter of the patients had the gastric bands removed because of complications or failure to lose weight.

Lisa Wilson, who was 46 in 2009 when she received her Lap-Band, didn't have access to any of those data while making her decision to undergo surgery. The implanted band constricts the stomach, making it unable to hold large amounts of food.

Wilson said that for her, the problems began immediately. She couldn't keep down even small amounts of food and was vomiting every day. As time wore on, the side effects of the band became more intense and in December 2010, it became clear that the band was cutting into the lining of her stomach and should be removed immediately. Wilson developed a post-surgical infection that left her with a collapsed lung.

John Santa, M.D., of the Consumer Reports Health Ratings Center asks how consumers would respond to a vehicle with a recall rate commensurate to the Lap-Band's 51 percent of complications and 25 percent outright failure of the device to perform as promised. “Consumers and regulators would be up in arms. But in the world of medical devices, these things often stay hidden.”

Dr. Stephen Tower of Alaska was a victim of a device that he himself had implanted into patients. The DuPuy ASR XL was all-metal hip replacement, supposedly advantageous over metal-and-plastic hips because it was often the plastic socket that wore out first on older models of artificial hip.

Initially upon receiving his new hip, Dr. Tower was overjoyed. He was able to return to athletic pursuits that he had enjoyed before arthritis in his hip had made them impossible. A year after his operation, however, things were not going well.

The doctor was in constant pain and his blood was showing elevated levels of the metals used to fashion the artificial ball and socket of the hip joint, a sign that the device was deteriorating. Then he started noticing other problems such as "disturbed sleep, mood swings and anxiety, hearing loss, visual problems, and tinnitus."

DePuy engineers insisted that they'd never seen anything like Tower's case, but his research, some of which has since been published in medical journals was turning up case after case of "profound poisoning" caused by debris from the implants turning up in patients' blood. Tower has had his hip re-replaced and his symptoms have since eased.

The DePuy hip was recalled, but not before thousands of patients had received them.

In 2011, the Institute of Medicine convened a panel that ruled that the current FDA review process for medical devices is inadequate. Consumers Union, the advocacy arm of Consumer Reports, agrees with the Institute of Medicine and has specific recommendations on how to make them safer, as well as guidelines for how patients can protect themselves against risks.

Below is a two-part CBS report about the Consumer Reports study, as well as information about the defective DePuy ASR XL artificial hips. The segments originally aired Wednesday, March 28:

Part One

Part Two