Antimicrobial-resistant organisms are not a unique threat to the endoscopy suite.
The issue, however, is a hot topic for the GI community thanks to growing antimicrobial resistance combined with ongoing endoscope reprocessing challenges.
“A common misconception about duodenoscopes, and duodenoscope cross-contamination, is that there’s something special about multidrug-resistant organisms that makes them more likely to be passed between patients by the scope itself,” Dr. Andrew Ross, medical director of the digestive health service line at Virginia Mason Franciscan Health, said in a presentation during Digestive Disease Week 2021.
But, really, multidrug-resistant organisms (MDROs) are “the canary in the coalmine,” Ross added — they are detectable and trackable and ultimately signal a “much larger” infection control problem.
If institutions are finding MDROs on duodenoscopes, it’s possible that other infectious organisms are also being passed between patients and going unnoticed by the institution, he said.
Experts like Ross discussed the risks of MDRO transmission in GI endoscopy and whether single-use duodenoscopes were the best way to mitigate the risk of patient infection following endoscopic retrograde cholangiopancreatography (ERCP). The Digestive Disease Week presentations were combined in a single virtual session about infection transmission in endoscopy.
“Undoubtedly as technology advances, [Food and Drug Administration] expectations will likely become more stringent,” said Dr. Bret Petersen, a professor of gastroenterology and hepatology at the Mayo Clinic. “There is still room for significant innovation, and I think the future is bright.”
Patients can be sick following endoscopy because of their own flora disturbed during an endoscopic procedure or the transmission of infectious organisms from the endoscopes themselves.
When it comes to the risk of exogenous infection — disease caused by bacteria from outside the body — David Slade, an infectious disease expert from Loyola University Medical center in Chicago, said Pseudomonas, Klebsiella, and E. coli are the three most common MDROs found on reprocessed GI endoscopes. He also noted the increasing emergence of carbapenamase in the endoscopy suite is a concern.
Post-market surveillance studies by the FDA have found inadequate reprocessing contributed to the continued contamination of endoscopes following disinfection. Endoscope reprocessing is a complex procedure that experts say leaves much room for error.
These studies were conducted in the wake of high-profile media coverage of MDRO infections following ERCP procedures in Seattle in 2015.
Slade also pointed out the risk presented by biofilms — complex matrices of cells that can form on the insides of endoscope channels. Once formed, biofilms are difficult to remove. They also shield microorganisms from high-level disinfection and “confer further resistance to antibiotics,” Slade said.
True exogenous infection rates in GI endoscopy are hard to quantify because of a lack of adequate surveillance and tracking. The latest multisociety guidelines for reprocessing GI endoscopes — updated in early 2021 — now include instructions for tracking patients and endoscopes.
Innovation Opportunities
Before addressing the promises of new disposable technology, Petersen looked at potential ways to improve endoscope reprocessing methods, including novel ways to brush and dry long endoscope channels.
“The manual washing step of reprocessing is likely the most fruitful arena for improvement,” Petersen said.
Some ways to ensure better manual cleaning may include automated washing or performance audits, he added.
Petersen also discussed new partially disposable duodenoscopes and sealing devices that are meant to protect the scope’s elevator mechanism from contamination. Duodenoscope elevator mechanisms pose a high threat of contamination because they are difficult to clean and disinfect.
Two single-use duodenoscopes used for ERCP have received FDA 510(k) clearance. Limited published data exists on the products' performance or their financial and environmental impacts.
Single-use duodenoscopes are “an attractive option as they could eliminate any cross-contamination risk,” according to Dr. Lukejohn W. Day, professor of medicine at the University of San Francisco.
During his DDW 2021 presentation, Day advocated for a multidisciplinary approach to infection prevention in GI endoscopy. That may include advancements in duodenoscope technology, such as single-use devices, but it also means addressing reprocessing pitfalls, he said.
Even given the small amount of clinical data available on single-use duodenoscopes, Day said there is promise that these devices can perform as well as their reusable counterparts. The lingering questions on financial and environmental impact need to be studied further before a full transition can be made.
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