Medical Tools That Spread Superbugs Have to Change

The FDA didn't pay attention to the sterilization of gadgets called endoscopes, and people died. New designs have to fix the problem.

Carbapenem-resistant Enterobacteriaceae (CRE) bacteria.


In the past few months, 11 people in Los Angeles who underwent surgical procedures using a device called a duodenoscope got sick---infected with a so-called superbug called CRE, carbapenem-resistant Enterobacteriaceae, likely carried by the scope from other patients the doctors used it on. Two of the CRE-infected patients died, joining the list of the more than 20,000 people who die every year from infections that antibiotics can't beat. And the people at the highest risk are the ones with the least say in the matter.

Over the last two years, endoscopes like the ones in the LA cases---long, snaking tubes that doctors use to look at your insides---have exposed dozens of people to drug-resistant bacteria. Some of those patients have now filed lawsuits against the manufacturers of the duodenoscopes; other suits have blamed hospitals for failing to adequately clean the devices between uses.

But the problem with medical devices and superbugs goes well beyond those lawsuits. The Food and Drug Administration, which approves the devices, is supposed to protect patients by ensuring that devices can be safely reused. And evidence suggests they haven't succeeded---in part because of the failures of manufacturers, and in part because of their own lax surveillance of those manufacturers.

Last week, the FDA released new guidelines for "reprocessing" medical devices---which is to say, sterilizing them between uses---in an effort to cut down on infections. But in the process of unveiling its new rules, the agency revealed that it hadn't been reviewing manufacturers' tests to ensure that the gadgets could be cleaned and disinfected between patients.

Now, the FDA says it's correcting that oversight; the agency will ask manufacturers to prove that cleaning procedures can eliminate the effluvia that get into their scopes' nooks and crannies.

That policy change could force a category-wide redesign. Over time, medical devices have become increasingly complex---and in general, that’s great. Big surgeries requiring large incisions and general anesthesia come with risks of complications and infections. Endoscopes let surgeons get to the inside of the body through smaller holes; parts like flexible plastic tubes, integrated electronics, and actuated biopsy collectors let surgeons cut down on more invasive procedures. But all those new components don't stand up to steam sterilization, so hospitals have to use complicated regimens of manual cleaning followed by chemical disinfection.

That's where the trouble starts. Newer medical devices have so many tiny crevices that it's impossible to know which ones will pick up bacteria. Duodenoscopes, for example, typically have a channel through which a wire travels to control an "elevator," a moving piece that helps direct tools through the scope. Over the last decade, manufacturers closed that channel, thinking it might have been filling up with bodily fluids.

But it was actually those closed-channel designs that doctors were using in the LA hospitals with the most recent CRE outbreaks. "We believe that closure of the channel may be associated with more difficulty in cleaning,” says Bill Maisel, deputy center director for science and chief scientist at the FDA’s Center for Devices and Radiological Health. In other words, the manufacturers' attempts to make their devices easier to disinfect may have instead made them more likely to transmit bacteria.

The FDA approved those closed-channel designs, too, of course---but apparently didn't look closely enough at whether they'd do what the manufacturers said they would. Now the agency is closing that loop. New guidelines direct manufacturers to consider alternative, easier-to-clean designs "from the earliest stages of device design and engineering." In an ideal world, that directive would lead manufacturers to design a totally disposable device, one that never risks transfer of bacteria between patients. At $40,000 a pop for a duodenoscope, though, "you can’t make them disposable," says Chris Lavanchy, engineering director at the non-profit ECRI Institute, which researches medical products. "But there may be ways to make them semi-disposable."

Broadly, this is a design and technology challenge. Maybe surgeons could switch out the channel between patients. New scopes could include flush ports or dedicated cleaning accessories, and if they have hinges maybe they'll be designed to be taken apart for cleaning, as older devices were. Since last year, the FDA has been harping on the three duodenoscope manufacturers---Olympus, Fujifilm, and Pentax---to provide proof that hospitals can safely sanitize their current scopes. But none of them have been able to. In the absence of that proof, they'll have to find a design that resists contamination.

But the same policy challenges that hamstrung the FDA in the first place are still in effect. While technically it could recall existing duodenoscopes, as a matter of practice that's not possible. "To withdraw these devices would leave us with more invasive alternatives for therapy for these patients," says Michael Kochman, chair of American Gastroenterological Association's Center for GI Innovation and Technology. "Those other alternative therapies have more risk to the patient than the risk of infection."

The FDA doesn't design new devices; it just says yes or no. "We don’t have the authority to require manufacturers to change their designs," says Maisel. That means waiting for better options to cross the agency's desks---and a years-long back-and-forth of proposals, rejections and amendments before any new approvals. In that time, CRE will continue its march across the country, accounting for more and more gut infections. Hopefully, in time, hospitals will get the right tools to fight back.