Disinfecting Duodenoscopes: Does the Method Make a Difference?

Over the last few years, duodenoscopes have been associated with outbreaks of multidrug-resistant organisms such as carbapenem-resistant Enterobacteriaceae (CRE). 

These scopes have shown a propensity for easing the transmission of multidrug-resistant organisms. There continues to be a strong infection control and regulatory focus on reprocessing to ensure patient safety. The flexible medical devices are used in endoscopic retrograde cholangiopancreatography (ERCP) procedures to help visualize and assess not only the small intestine, but also the pancreas and bile ducts. 

Because of the device’s intricate design, duodenoscopes are often more difficult to disinfect than other tools, such as endoscopes. The US Food and Drug Administration (FDA) even issued a recommendation over the summer for duodenoscope manufacturers and healthcare facilities alike to move towards scopes with disposable components, specifically the endcaps. 

“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,” Jeff Shuren, MD, JD, 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.” 

In research presented recently at the American College of Gastroenterology’s Annual Scientific Meeting, investigators with Indiana University School of Medicine compared disinfection methods to determine whether reprocessing duodenoscopes with double high-level disinfection (DHLD) or chemical sterilization is more effective. 

The prospective study analyzed 2 methods of duodenoscope reprocessing between October 2017 and September 2018, randomly culturing the tools post-reprocessing for surveillance. The first DHLD method comprised complete manual cleaning followed by automated reprocessing, repeated for 2 total cycles. The second method involved liquid chemical sterilization. 

Investigators performed a total of 878 post-reprocessing surveillance cultures (453 in the DHLD group and 425 in the sterilization group). Out of all the samples collected, 17 (1.9%) were positive. Two cultures from both study groups grew high-concern organisms, but no multidrug-resistant organisms were detected. When comparing the 2 disinfection methods, there was no significant difference of positive cultures between DHLD (8 positive cultures, 1.8%) and chemical sterilization (9 positive cultures, 2.1%, p>0.05).

“DHLD and liquid chemical sterilization both resulted in a low rate of positive cultures, both for all organisms and for high-concern organisms, but neither process eliminated positive cultures from reprocessed duodenoscopes,” investigators concluded. “A liquid chemical sterilization protocol did not improve the growth of organisms on surveillance cultures compared to DHLD.”