Advancing to Sterilization

The high infection rate associated with flexible endoscopes remains a significant challenge in healthcare globally despite advancements in reprocessing techniques. Endoscope-associated infections (EAIs) have been a persistent issue, with recent data indicating that infection rates following endoscopic procedures are higher than previously reported. The infection rate for certain endoscopic procedures can be as high as 1 in 1,000.¹ Even with improvements in device design, reprocessing methods and equipment, and staff training and oversight, pathogen transmission from persistent contamination of flexible gastrointestinal endoscopes continues to occur.²

Human errors and variability are inevitable and can increase the risk of breaches in the reprocessing protocol. Staffing shortages, coupled with the complexity and length of reprocessing instructions, contribute to increasing time-constrained pressure on healthcare workers. It is imperative for healthcare organizations to use the most effective and robust reprocessing technology to reduce the chances of infection transmission and increase the margin of safety for patients.³

Infection Outbreaks

Inadequately cleaned endoscopes have been implicated in multiple drug-resistant organism (MDRO) infection outbreaks4 and continue to be reported to the FDA related to patient safety concerns. In cases of outbreaks related to MDROs, the failures in the processing or the equipment were not always identified even though the facilities followed the guidelines and manufacturers’ written instructions for use (IFU).⁴ “Flexible endoscopes are complex medical devices that require equally complex processes for effective cleaning and sterilization or HLD. Even the most rigorous processing methods can be undermined by the design of the device or contamination of the endoscope during handling, rinsing, drying, transport or storage.”⁵

Endoscope Design: A Reprocessing Challenge

The complexity of endoscope design, particularly in devices like reusable duodenoscopes, makes thorough cleaning and disinfection difficult, leading to residual contamination and subsequent infections.⁶ Reprocessing instructions can be very lengthy and describe more than 100 specific steps for personnel to execute. Current guidelines also do not specify a minimum amount of time required for manual cleaning, leading to wide variations in practice and potentially inadequate removal of bioburden.⁷

In recent years, most endoscope manufacturers have enhanced duodenoscope designs and brush models to improve cleaning and facilitate access to the intricately designed and hard-to-clean areas such as the distal end. Yet, the long lumens of these devices remain common sources of hidden microorganisms.⁷

Reprocessing: Increasing the Level of Assurance

The reprocessing of medical instruments is a critical component in ensuring patient safety in healthcare settings. Two primary methods used to decontaminate medical instruments are high-level disinfection (HLD) and sterilization, both of which aim to reduce the risk of infection transmission. These methods differ in their efficacy and procedures, as well as the level of safety they provide.

High-Level Disinfection vs. Sterilization: What’s the Difference?

HLD is a process designed to eliminate all microorganisms, except for bacterial spores, which are highly resistant to disinfection.⁸ HLD typically involves the use of chemical disinfectants and results in a lower margin of safety compared to sterilization. Sterilization, on the other hand, is the most thorough method for eliminating all microorganisms, including bacterial spores, viruses, fungi and bacteria. The process involves exposing instruments to high-pressure steam, gas or hydrogen peroxide vapor.⁸

The margin of safety decreases when processing flexible endoscopes, especially when using HLD instead of sterilization modalities.⁵ Evidence to support sterilizing all flexible endoscopes (semi-critical and critical) includes: high microbial load after patient procedure,⁴ complex design of flexible endoscopes, and risk for biofilm formation.⁴

Sterilization modalities also reduce the potential risks for an endoscope to become recontaminated post-disinfection. During HLD, the water, pipes and tubings used in automatic endoscope reprocessors (AERs) can potentially harbor harmful microorganisms if not monitored and disinfected routinely. Poor handling techniques post-HLD and during storage are also potential sources of transmission of microorganisms.⁹ Sterilized scopes are packaged and sealed prior to sterilization, reducing the risk of recontamination.

Sterilization: Elevating the Standard of Care

The goal of sterilization is to provide a higher level of assurance that all potential pathogens have been eliminated to minimize the risk of healthcare-associated infections (HAIs). As healthcare professionals strive to improve patient outcomes and reduce the incidence of EAIs, there is an increasing call to transition from HLD to sterilization.⁶ By adopting sterilization practices, healthcare facilities can better protect patients from the risks associated with endoscopic procedures, which contributes to safer and more effective healthcare delivery worldwide.

Sterilizing semi-critical devices enables compliance with Spaulding’s classification. Semi-critical endoscopes that enter a mucous membrane (non-sterile tissue), yet indirectly contact normally sterile tissue or enter the bloodstream, should be classified as critical devices.⁹ The Canadian Standards and Guidelines have classified bronchoscopes, laryngoscopes, cystoscopes and ureteroscopes as critical devices and have required their sterilization since 2018.¹⁰

High-risk endoscopes that have been associated with infectious outbreaks include bronchoscopes, cystoscopes, duodenoscopes, endobronchial ultrasound endoscopes, linear ultrasound endoscopes, and ureteroscopes. These scopes are difficult to process and pose an increased risk of incomplete cleaning of contaminating infectious organisms.4 According to AORN, “Sterilization provides the greatest margin of safety and assurance that the endoscope is safe for patient use. Correctly handled and sterilized items are rarely associated with patient infection.”5 Terminally sterilized endoscopes are rendered completely dry, packaged (which reduces the chance of contamination for longer periods of time), and are patient-ready. Packaged endoscopes have tamper-evident seals that clearly distinguish “used” endoscopes from “patient-ready endoscopes.”⁴

Culture of Safety

The Joint Commission has emphasized the importance of creating a culture of safety, notably in the context of medical instrument reprocessing. This culture focuses on reducing variations, reducing risk, and improving patient care with quality management systems.¹¹

In the case of endoscopes, which are among the most used and complex instruments requiring reprocessing, the need for careful documentation and traceability is even more pronounced. With their high level of complexity, improperly reprocessed endoscopes can lead to significant patient harm. In the event of an endoscope-related infection outbreak, the ability to track each step of the reprocessing process is crucial to a rapid investigation and patient protection.¹²

Terminal sterilization offers a higher quality assurance over other modalities because the level of sterilization is accompanied by quality process monitors that verify the efficacy of the sterilization.¹³ By aligning the culture of safety, best practices and quality assurance, healthcare facilities can meet the highest standards of safety and quality of care.

Conclusion: Sterilization is the Gold Standard

Many people will become a patient receiving an endoscopy procedure as part of preventative or diagnostic healthcare in their lifetime. For healthcare providers and personnel who provide endoscopy procedures, there is great satisfaction in supporting patient care through these lifesaving procedures. Endoscopes play a vital role in the effective delivery of healthcare; however, risks associated with unintentional transmission of infectious organisms via endoscopes continue to be a significant concern. The complexity of endoscope design presents a challenge to achieving consistent and effective processing. Although risk-mitigation steps are detailed in manufacturers’ IFU, these steps fail to account for the high-risk design elements, such as long, internal lumens and recessed spaces that either cannot be visualized or are difficult to visualize.⁴

The process of improving patient safety in flexible endoscopy requires clear guidance on endoscope processing, effective training and competency verification of personnel, comprehensive quality-control systems, validated methods for ensuring adequate processing, and designing processes with margins of safety that account for the level of risk associated with use of these devices.¹⁴ As part of this process, the healthcare industry should support and encourage continued research and partnerships between endoscope, reprocessor and sterilizer manufacturers to elevate the standard of endoscope processing from high-level disinfection to sterilization.⁴

Current guidance from professional organizations recommends sterilization whenever possible for processing reusable flexible endoscopes that are manufacturer-validated for sterilization.^4,5 Many endoscopy departments and facilities have successfully transitioned the processing of high-risk endoscopes to low-temperature sterilization.¹⁵ Through thoughtful planning and staff education, healthcare facilities can implement changes in endoscope processing practices and workflow with minimal disruption. Leaders can positively influence the success of these transitions by keeping their teams focused on the outcomes of preventing infection outbreaks and improving patient safety.

References

1. Saleh N. Post-endoscopic infection rates are higher than ‘1 in a million’. MDLinx. Published July 12, 2018. https://www.mdlinx.com/article/post-endoscopic-infection-rates-are-higher-than-1-in-a-million/lfc-2029.
2. Benowitz I, Moulton-Meissner HA, Epstein L, Arduino MJ. The Centers for Disease Control and Prevention Guidance on Flexible Gastrointestinal Endoscopes: Lessons Learned from Outbreaks, Infection Control. Gastrointest Endosc Clin N Am. 2020 Oct;30(4):723-733. doi: 10.1016/j.giec.2020.06.009. Epub 2020 Aug 1. PMID: 32891228; PMCID: PMC7962740.
3. Ofstead, C. L., Buro, B. L., Hopkins, K. M., Eiland, J. E., Wetzler, H. P., & Lichtenstein, D. R. (2020). Duodenoscope-associated infection prevention: A call for evidence-based decision making. Endoscopy International Open, 08(12), E1769–E1781. https://doi.org/10.1055/a-1264-7173
4. Association for the Advancement of Medical Instrumentation (AAMI). American National Standards Institute (ANSI). ANSI/AAMI ST91:2021. Flexible and semi-rigid endoscope processing in health care facilities. AAMI.
5. Association of PeriOperative Registered Nurses. (2023). eGuidelines for Perioperative Practice: Flexible Endoscopes.
6. Adler, D. G, Yu, A., & Barakat, M. T. (2024). Frontiers in endoscopy, Series #89 Disposable endoscopes: Current status and future directions. Practical Gastroenterology. https://practicalgastro.com/2024/03/19/disposable-endoscopes-current-status-and-future-directions/
7. van der Ploeg, K., Vos, M. C., Erler, N. S., Bulkmans, A. J. C., Mason-Slingerland, B. C. G. C., Severin, J. A., & Bruno, M. J. (2024). Impact of duodenoscope reprocessing factors on duodenoscope contamination: a retrospective observational study. Journal of Hospital Infection, 154, 88–94. https://doi.org/10.1016/j.jhin.2024.09.018
8. Centers for Disease Control (CDC) and Prevention. (2008;2024). Guideline for disinfection and sterilization in healthcare facilities. U.S Department of Health and Human Services. https://www.cdc.gov/infection-control/hcp/disinfection-and-sterilization/index.html
9. Rutala, W.A., Weber D. J. (2023) Reprocessing semicritical items: An overview and an update on the shift from HLD to sterilization for endoscopes, p.98 American Journal of Infection Control https://doi.org/10.1016/j.ajic.2023.01.002
10. Canadian Standards Association (CSA) Group, National Standard of Canada (2023). Canadian medical device reprocessing in all healthcare settings, Z314:23, 12.6.1, p.161
11. The Joint Commission. (2025, January). Comprehensive Accreditation Manual for Nursing Care Centers ( CAMNCC) Update 2, 2025, Patient Safety Systems, number 4 CAMNURSINGCARECENTER_PS_Jan_2025.pdf, p.1
12. Multidisciplinary and Multisociety Practice Guideline on Reprocessing Flexible Gastrointestinal Endoscopes and Endoscopic Accessories. (2020). Clinical Endoscopy, 53(3), 276–285. https://doi.org/10.5946/ce.2020.106
13. Klacik, S.G., Transitioning from High-Level Disinfection to Sterilization for Semicritical Devices, AAMI/ARRAY, 2019, Transitioning from High-Level Disinfection to Sterilization for Semicritical Devices, https://array.aami.org/doi/epdf/10.2345/0899-8205-53.s2.23
14. (2022). Infections Associated with Reprocessed Duodenoscopes. FDA. https://www.fda.gov/medical-devices/reprocessing-reusable-medical-devices/infections-associated-reprocessed-duodenoscopes
15. Nadeau, K. (2024, August 27). Key Considerations for Transitioning Scopes from HLD to Sterilization. Hpnonline.com; Healthcare Purchasing News. https://www.hpnonline.com/sterile-processing/article/55129311/key-considerations-for-transitioning-scopes-from-hld-to-sterilization