Four medical implants that escaped FDA scrutiny

April 30, 2012 by MassDevice

hip implants

A traditional artificial hip, left, and an FDA-approved metal-on-metal model called the Birmingham hip, right.

by Lena Groeger, ProPublica

Medical devices sustain and improve the quality of life for millions of Americans. But as the over $100 billion-a-year industry pushes thousands of devices to market every year, reports of faulty devices, repeat surgeries, and recalls have increased. The FDA and the industry maintain that a speedy approval process gives patients faster access to life-saving devices. But critics say that unlike drugs, a substantial number of risky devices are cleared without clinical testing, and receive almost no oversight once on the market.

We've taken a closer look at four types of implantable medical devices that have drawn the most criticism.

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Hundreds of thousands of people with advanced arthritis get total hip replacements each year, surgically replacing their hip joint with a prosthetic. Typically, implants are made up of a metal head that rotates inside a plastic cup. But in 2005, Johnson & Johnson's DePuy Orthopaedics introduced a new all-metal design. Maintaining that the new device was substantially equivalent to older models, DePuy got clearance for the hip device without conducting any clinical trials to test how it would perform in patient's bodies. The company was able to do that through an FDA process called 510(k), which doesn't require clinical data as long as manufacturers can show that their new device is "substantially equivalent" to one already on the market.

In the case of DePuy's hip implant, that testing began once the implants went to market.

According to the British Hip Society, the failure rate of the DePuy implant was so high that almost half of all patients who got the implant required surgery within six years to fix problems. The metal was eroding, releasing metallic particles into the blood and surrounding tissue of the joint and causing tremendous pain (the New York Times has an explanatory graphic of this failure.) After thousands of complaints and lawsuits, the device was recalled in 2010, after it had been implanted in almost 100,000 people. DePuy said the company continuously reviewed data about the hip implant while it was on the market, and initiated the recall as soon as new information confirmed a problem.

Last year the Institute of Medicine reviewed the clearance process for medical devices and called for the 510(k) process to be eliminated altogether because it could not guarantee safe devices. They found that from 2005 to 2009, three out of four recalled high-risk devices had not been approved with clinical data, but rather had gone through the 510(k) clearance process or had been exempt from review altogether.

Furthermore, a Government Accountability Office report found that once recalled, many of the highest-risk devices are not corrected or removed from the market.

Surgical Mesh

Surgical Mesh

Implantable surgical mesh acts a reinforcement structure for internal organs, and is often used to treat pelvic organ prolapse or stress urinary incontinence in women.

The FDA first cleared vaginal mesh in the late 1990's based on its similarity to earlier products used to fix internal hernias. Despite using a different method of implantation (inserted through the vaginal wall, rather than with abdominal surgery) and for an entirely different part of the body, surgical mesh "kits" were advertised as a new and improved method to treat urinary incontinence.

In 1999, Boston Scientific voluntarily recalled its surgical mesh product called the ProteGen Sling, after numerous complaints of pain, infections, and injuries. Over a decade later, Johnson & Johnson faced hundreds of lawsuits over a surgical mesh device that was substantially similar (in fact had been cleared based on its similarity) to the Protogen Sling.

In 2008 the FDA said that surgical mesh complications were serious, but rare. Over the next two years, complaints grew to the thousands, and doctors and patients reported five times as many mesh complications as previous years. According to a 2011 FDA report, total "adverse event" reports for all medical devices – not just mesh – have risen an average of 15 percent a year for the past decade.

In the case of vaginal mesh, the most common problem was mesh eroding and sticking through the walls of the bladder or vagina, causing burning and pain. A study in the journal Obstetrics and Gynecology found that 15 percent of the women treated with vaginal mesh had complications, and that the mesh was no more helpful than other repair treatments. Boston Scientific has repeatedly stated that mesh is a safe and effective treatment option.

In July 2011, the FDA said that serious complications with mesh are "not rare" and may expose patients to more risk. In January of this year, the FDA finally ordered manufacturers to conduct studies of surgical mesh.

Heart Valve Rings

Heart Ring

A variety of commercially available heart valve repair rings.

An annuloplasty ring is a circular device used to repair faulty heart valves, by pinching together two flaps that normally prevent blood from leaking back into the lungs or another heart chamber. Given their critical role in sustaining life, the rings were originally classified in the highest risk class. For these very high-risk devices, manufactures often go through a premarket approval (PMA) process, which requires clinical data that a
device is safe.

But the FDA also clears dozens of high-risk medical devices each year through the less stringent 510(k) process – and over the past decade, that number has increased dramatically.

Number of high-risk devices approved through PMA versus 510(k)*

*Includes high risk devices in cardiovascular care, neurology, obstetrics, gynecology, and orthopedics. Data from the FDA and Harvard Medical School.

In 1997, after being petitioned by manufacturers, the FDA brought the heart valve rings down to a lower risk class, alongside hearing aids and glucose monitors. With a lower risk, manufacturers could more quickly — and cheaply — gain clearance.

In the case
of a heart ring called the Myxo ring, the manufacturers Edwards Lifesciences didn't seek clearance through the 510(k) — or any other process. Starting in 2006, the device was implanted in over a hundred people without FDA clearance, which current regulations allow. According to the agency, manufacturers with a cleared device on the market can make changes or modifications to the product without needing to submit an entire new application.

While patients didn't report any major complaints with the ring, many were troubled by the fact that a life-sustaining device could be on the market without any FDA supervision. Edwards Lifesciences maintained the ring was safe, but voluntarily recalled the device and applied for clearance.

In April 2009, after the Moxa ring had been subject to an FDA investigation and a Senate inquiry, the FDA retroactively cleared the device under a new name, saying it was safe. The agency said that Edwards Lifesciences should have sought clearance, but that they made an "honest attempt" to interpret the regulations.*

Defibrillator Leads

Heart Ring

An x-ray picture of a defibrillator device and lead

Implantable defibrillator leads are wires that connect defibrillators (devices similar to pacemakers) to the heart. Defibrillators automatically monitor and administer shocks to the heart, and a malfunction can cause the device to fire unexpectedly, or fail to fire when a patient's life depends on it. Over the past decade, the $10 billion dollar heart device industry has seen several high profile cases of malfunctioning products that posed severe risks to patients.

The most recent episode concerns the St Jude's Riata lead, which has been implanted in approximately 79,000 people in the United States. Last year the device was recalled after it became clear that electrodes inside the lead could erode out of their lining, exposing electrical wire to the body and potentially causing a short circuit.

Manufacturers had known about the problems with the Riata for a while. In fact, a full year before the recall, St. Jude stopped selling the device and sent a letter to doctors describing the problem.

A recent study found that the Riata lead was prone to yet another type of failure (malfunctioning at high voltages) and had been responsible for at least 20 deaths. St. Jude disputed the accuracy of the study, saying it was based on incomplete data. In a recent statement, the company said it has made significant design changes to its newer lead models to address these safety issues, and is also currently conducting an evaluation study of the Riata lead.

Critics point to the Riata lead as an example of FDA failure to adequately monitor devices once they go to market. A Government Accountability Office report found multiple problems with FDA oversight, including a passive system dependent on voluntary reports and a lack of complete information about how devices are used and who uses them.

The FDA says it is currently working on a national surveillance strategy.

Image Sources: Reuters, The Associated Press, Wikimedia Commons, Flickr

*[Eds. note: After this article appeared, Edwards sent the following statement to MassDevice.com and ProPublica.]:
"The U.S. Food & Drug Administration (FDA) has a rigorous, science-driven process for reviewing new medical technologies that Edwards Lifesciences respects and follows closely. Edwards has been on the record multiple times on this topic, and FDA has stated we "made a good faith effort" and an "honest attempt" to follow its guidance when Edwards used FDA's Justification to File (JTF) process in 2006 to introduce its 5100 ring. Occasionally, the FDA reviews a manufacturer's decision and disagrees, and this is what took place with the 5100 ring. Additional FDA review was conducted, the FDA cleared the ring, and the rings being sold today are identical to the products sold earlier under the JTF authorization, except for the name."

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