A group of U.S. lawmakers are calling for an investigation into a growing number of reported problems with 2 medical devices that are causing major concerns for many, metal-on-metal artificial hips, as well as Wingspan brain stents.
Democrats on the House Energy and Commerce Committee wrote a letter to several Republican chairmen on October 12, calling for an investigation into the two devices. In the letter, Representative Henry Waxman (D-CA), leader of the Committee, requested that hearings be scheduled in order to formally discuss the approval process of medical devices in question.
“Both items are examples of devices that were found to be associated with major health problems after being approved or cleared by the FDA,” committee Democrats wrote. “As such, we believe they could provide important lessons about the device clearance and approval process as well as the adequacy of our postmarketing safety system.”
Let’s take a look at each device and consider the problems they seem to be causing.
Metal-on Metal Artificial Hips
Metal-on metal artificial hips are causing consumers to experience early failure of their implant and other complications associated with blood poisoning from the metal hip replacement systems.
As the metal hip replacement parts rub against each other, microscopic particles of cobalt and chromium may be shed into the body, which can result in metal poisoning, also known as metallosis. This may result in soft tissue damage, inflammatory reactions, bone loss, genetic damage, asceptic fibrosis, local necrosis or other problems that may lead to the need for a risky hip revision surgery.
In the first six months of 2011, the FDA has received more than 5,000 complaints involving metal artificial hip complications from doctors and patients. Many of those complaints are linked to complications with the DePuy ASR metal hip implant, which were recalled in August 2010, after it was implanted in approximately 90,000 people.
However, metal hip complications have also been associated with other devices, including the DePuy Pinnacle metal hip and other models made by a number of different manufacturers.
A few years ago, metal-on-metal hip implants accounted for about one-third of the 250,000 hip replacements performed each year in the United States. However, over the past two years, concerns have increased about the risk of metal hip replacement complications, resulting in use of the implants dropping to just 5% of the artificial hip market.
In May 2011, the FDA requested artificial hip manufacturers to provide more data on the risk of metal poisoning from hip replacement implants.
Wingspan Brain Stent
The lawmakers are also calling for an investigation into problems with the Wingspan brain stent, which were discovered during a study that was stopped earlier this year. The study compared the effectiveness of the brain stent to Plavix and aspirin, but it was brought to a halt after almost 15% of test subjects had a stroke or died within the first month of having the stent implanted.
The Wingspan brain stent was approved in 2005 by the FDA and was supposed to be a more effective way of opening up blocked arteries in the brain after a stroke. It was hoped that the devices would prevent future strokes more effectively than blood thinners.
However, not only did a large number of patients experience strokes and death, about 15 percent of the patients who received the Wingspan brain stent, manufactured by Natick, have either suffered a stroke or died within just 30 days of their procedure, but results from the aborted study found that it was less effective at preventing them than Plavix and aspirin.
House Democrats said that the two devices were indications of problems with the FDA’s approval process and urged Republicans to hold hearings on their approval and on recent recommendations by the Institute of Medicine, which called for an end to FDA’s 510(k) accelerated approval process, which fast-tracks medical devices onto the market without clinical testing.