From the AGA Journals

Confronting endoscopic infection control

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Cost, environmental impact remain issues

The future remains to be seen

Solutions surrounding proper endoscope reprocessing and infection prevention have become a major focus of investigation and innovation in endoscope design, particularly related to duodenoscopes. As multiple infectious outbreaks associated with duodenoscopes have been reported, the complex mechanism of the duodenoscope elevator has emerged as the target for modification because it is somewhat inaccessible and difficult to adequately clean.

Jennifer Maranki, MD, MSc, is professor of medicine and director of endoscopy at Penn State Hershey (Pennsylvania) Medical Center

Dr. Jennifer Maranki

As a result of the challenges associated with duodenoscope reprocessing, the FDA recommended additional measures be implemented by facilities to help mitigate the infectious risk of duodenoscopes. Current research is being conducted on novel sterilization techniques as well as several point-of-care reprocessing quality indicators. Despite improvements in reprocessing quality, residual contamination of duodenoscopes led the FDA to recommend in 2019 that all units using duodenoscopes transition to duodenoscopes with disposable design elements. In addition, fully disposable duodenoscopes have been developed, with two types currently available in the United States.

One of the major considerations related to disposable duodenoscopes is the cost. Currently, the savings from removing the need for reprocessing equipment, supplies, and personnel does not balance the cost of the disposable duodenoscope. Studies on the environmental impact of disposable duodenoscopes suggest a major increase in endoscopy-related waste.

In summary, enhanced reprocessing techniques and modified scope design elements may not achieve adequate thresholds for infection prevention. Furthermore, while fully disposable duodenoscopes offer promise, questions remain about overall functionality, cost, and the potentially profound environmental impact. Further research is warranted on feasible solutions for infection prevention, and the issues of cost and environmental impact must be addressed before the widespread adoption of disposable duodenoscopes.

Jennifer Maranki, MD, MSc, is professor of medicine and director of endoscopy at Penn State Hershey (Pennsylvania) Medical Center. She reports being a consultant for Boston Scientific.


 

FROM TECHNIQUES AND INNOVATIONS IN GASTROINTESTINAL ENDOSCOPY

The reprocessing of endoscopes following gastrointestinal endoscopy is highly effective for mitigating the risk of exogenous infections, yet challenges in duodenoscope reprocessing continue to persist. While several enhanced reprocessing measures have been developed to reduce duodenoscope-related infection risks, the effectiveness of these enhanced measures is largely unclear.

Rahul A. Shimpi, MD, and Joshua P. Spaete, MD, from Duke University, Durham, N.C., wrote in a paper in Techniques and Innovations in Gastrointestinal Endoscopy that novel disposable duodenoscope technologies offer promise for reducing infection risk and overcoming current reprocessing challenges. The paper notes that, despite this promise, there is a need to better define the usability, costs, and environmental impact of these disposable technologies.

Current challenges in endoscope reprocessing

According to the authors, the reprocessing of gastrointestinal endoscopes involves several sequential steps that require a “meticulous” attention to detail “to ensure the adequacy of reprocessing.” Human factors/errors are a major contributor to suboptimal reprocessing quality, and these errors are often related to varying adherence to current reprocessing protocols among centers and reprocessing staff members.

Despite these challenges, infectious complications associated with gastrointestinal endoscopy are rare, particularly in relation to end-viewing endoscopes. Many high-profile infectious outbreaks associated with duodenoscopes have been reported in recent years, however, which has heightened the awareness and corresponding concern with endoscope reprocessing. Many of these infectious outbreaks, the authors said, have involved multidrug-resistant organisms.

The complex elevator mechanism, which the authors noted “is relatively inaccessible during the precleaning and manual cleaning steps in reprocessing,” represents a paramount challenge in the reprocessing of duodenoscopes. The challenge related to this mechanism potentially contributes to greater biofilm formation and contamination. Other factors implicated in the transmission of duodenoscope-associated infections from patient to patient include other design issues, human errors in reprocessing, endoscope damage and channel defects, and storage and environmental factors.

“Given the reprocessing challenges posed by duodenoscopes, in 2015 the Food and Drug Administration issued a recommendation that one or more supplemental measures be implemented by facilities as a means to decrease the infectious risk posed by duodenoscopes,” the authors noted, including ethylene oxide (EtO) sterilization, liquid chemical sterilization, and repeat high-level disinfection (HLD). They added, however, that a recent U.S. multisociety reprocessing guideline “does not recommend repeat high-level disinfection over single high-level disinfection, and recommends use of EtO sterilization only for duodenoscopes in infectious outbreak settings.”

New sterilization technologies

Liquid chemical sterilization may be a promising alternative to EtO sterilization because it features a shorter disinfection cycle time and less endoscope wear or damage. However, clinical data for the effectiveness of LCS in endoscope reprocessing remains very limited.

The high costs and toxicities associated with EtO sterilization may be overcome by the plasma-activated gas, another novel low-temperature sterilization technology. This newer sterilization technique also features a shorter reprocessing time, thereby making it an attractive option for duodenoscope reprocessing. The authors noted that, although it showed promise in a proof-of-concept study, “plasma-activated gas has not been assessed in working endoscopes or compared directly to existing HLD and EtO sterilization technologies.”

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