In the latest move to improve duodenoscope safety, the FDA has recommended transitioning from fixed endcap duodenoscopes to those with replaceable endcaps — or other newer designs.

“The FDA believes the best solution to reducing the risk of disease transmission by duodenoscopes is through innovative device designs that make reprocessing easier, more effective, or unnecessary,” it said in a statement.

At the same time the agency acknowledged that such a shift will not happen overnight.

"We recognize that a full transition away from conventional duodenoscopes to innovative models will take time and immediate transition is not possible for all healthcare facilities due to cost and market availability," Dr. Jeff Shuren, director of the FDA's Center for Devices and Radiological Health, said in a statement. "This is why we're communicating with healthcare facilities now — so they can begin developing a transition plan to replace conventional duodenoscopes, and those facilities that are purchasing duodenoscopes with fixed endcaps can invest in the newer, innovative models. We are also encouraging the manufacturers of these duodenoscope models to assist health care facilities with their transition plans.”

The newer-design endcaps aim to improve cleaning. With fixed-endcap duodenoscopes, a plastic or rubber cap is glued to the metal edges around the distal end and may prevent tissue damage but also limits accessibility for cleaning.

“We continue to address challenges with current reprocessing methods and support expanding the types of validated methods available to reprocess duodenoscopes,” the agency stated, while calling the infection risk from inadequate reprocessing “relatively low.”

It provided guidelines for clinicians and facilities, including:

– Consider using duodenoscopes that have disposable components, if available at your facility.
– Make sure reprocessing instructions are “meticulously” followed.
– Ensure that standard quality control programs also include regular sampling and microbiological culturing.
– Consider adding extra steps to reprocessing, including sterilization or use of a liquid chemical sterilant processing system in line with device labeling.
– Implement routine inspection and periodic maintenance along the lines of scope maker instructions.

These steps are warranted, because despite all ongoing efforts, field-monitoring studies by makers Fujifilm, Olympus, and Pentax “continue to show elevated rates of contamination, including the presence of high-concern organisms, defined as organisms that are more often associated with disease transmission, such as E. coli and Pseudomonas aeruginosa,” the agency warned.

At this time, there are two FDA-cleared, disposable-endcap duodenoscopes: the Fujifilm model ED-580XT (cleared under K181745), and the Pentax model ED34-i10T (cleared under K163614 and K181522).

In addition, the agency has ordered disposable-endcap-duodenoscope makers to do postmarket studies on contamination rates. When these studies are done, scope labeling would “be updated with contamination rate data,” it suggested.

This will allow informed decisions by both patients and healthcare professionals.

In other scope news, the FDA warned that some are assessing cleaning procedures with adenosine triphosphate, or ATP, test strips.

“These test strips claim to indicate the presence of live microbes inside of duodenoscopes,” warned the agency, noting that “to date, the FDA is not aware of any legally marketed ATP test strips cleared by the agency for this use, which means the FDA has not reviewed them for effectiveness in assessing reprocessing.”

In April, information from postmarket studies on contamination rates after cleaning and reprocessing of Olympus, Fujifilm and Pentax duodenoscopes revealed that “up to 5.4 percent of all properly collected samples tested positive for 'high concern' organisms, which is significantly higher than the earlier results,” Shuren said in a statement at the time.

In December 2018, the agency reported a three percent contamination rate for “high concern” organisms, such as E. coli or Staphylococcus aureus.

While recent actions to better reprocessing have “yielded improvements,” he added, “we also received reports of three deaths of U.S. patients in 2018 that were related to infections associated with duodenoscopes. That’s three deaths too many.”