Flexible Endoscope Reprocessing: The Journey of a Dirty Endoscope

Endoscopy is a procedure to visually examine the inside of the body using an endoscope. Duodenoscope is an example of a flexible endoscope used in endoscopic retrograde cholangiopancreatography (ERCP) procedures and have received attention due to the infections associated with the improper reprocessing in recently years.1 

Duodenoscope are complex instruments that contain intricate working parts, and if not thoroughly cleaned and disinfected, tissue or fluid from one patient can remain when it is used on a subsequent patient.1

Seven Critical Steps for Flexible Endoscope Reprocessing

The Center for Disease Control (CDC) recommends the following critical reprocessing steps to ensure endoscopes are safe for patient use. The chart below is a summary of the CDC’s guidance:2

 STEPS IN PROCESSWHAT IS IT?WHY IS IT IMPORTANT?
1PRE-CLEANINGCleaning often performed in the examination room immediately following the procedure.2Helps prevent the formation of biofilm on the instrument.2
2LEAK-TESTTest to detect damage to the external and internal channels of the scope.2A leak can lead to inadequate disinfection and further damage of the endoscope.2
3MANUAL CLEANINGManual cleaning including brushing and flushing channels and ports consistent with the manufacturer’s instructions for use (IFU).2The most critical step in the disinfection process since remaining organic material can reduce the effectiveness of high-level disinfection (HLD) and sterilization.2
4VISUAL INSPECTIONVisually inspect the endoscope and its accessories.2Visual inspection provides additional assurance that the endoscope and its accessories have been throughly cleaned and are free of any visible defects.2
5DISINFECTIONPerform high-level disinfection and adhere to the drying instructions and time as specified in the manufacturer’s IFU.2Follow the manufacturer’s instructions and IFU to ensure effective disinfection and maintain compliance for patient safety.2
6STERILIZATIONAdhere to the drying instructions and time, then carry out sterilization as directed in the manufacturer’s IFU.2Follow the manufacturer’s instructions and IFU to ensure effective sterilization and maintain compliance for patient safety.2
7STORAGEProperly store endoscope and its accessories. If sterilizing, follow instructions andIFU for properly storing sterile medical instruments.2Store endoscopes and its accessories in a way that prevents recontamination, protects the instrument from damage and promotes drying.2
8DOCUMENTATIONMaintain documentation of these steps each time an endoscope is reprocessed.2Documentation is necessary for quality assurance purposes and for patient tracing if necessary.2

1. PRE-CLEANING

WHAT IS IT?

Cleaning often performed in the examination room immediately following the procedure.2

WHY IS IT IMPORTANT?

Helps prevent the formation of biofilm on the instrument.2

2. LEAK-TEST

WHAT IS IT?

Test to detect damage to the external and internal channels of the scope.2

WHY IS IT IMPORTANT?

A leak can lead to inadequate disinfection and further damage of the endoscope.2

3. MANUAL CLEANING

WHAT IS IT?

Manual cleaning including brushing and flushing channels and ports consistent with the manufacturer’s instructions for use (IFU).2

WHY IS IT IMPORTANT?

The most critical step in the disinfection process since remaining organic material can reduce the effectiveness of high-level disinfection (HLD) and sterilization.2

4. VISUAL INSPECTION

WHAT IS IT?

Visually inspect the endoscope and its accessories.2

WHY IS IT IMPORTANT?

Visual inspection provides additional assurance that the endoscope and its accessories have been throughly cleaned and are free of any visible defects.2

5. DISINFECTION

WHAT IS IT?

Perform high-level disinfection and adhere to the drying instructions and time as specified in the manufacturer’s IFU.2

WHY IS IT IMPORTANT?

Follow the manufacturer’s instructions and IFU to ensure effective disinfection and maintain compliance for patient safety.2

6. STERILIZATION

WHAT IS IT?

Adhere to the drying instructions and time, then carry out sterilization as directed in the manufacturer’s IFU.2

WHY IS IT IMPORTANT?

Follow the manufacturer’s instructions and IFU to ensure effective sterilization and maintain compliance for patient safety.2

7. STORAGE

WHAT IS IT?

Properly store endoscope and its accessories. If sterilizing, follow instructions andIFU for properly storing sterile medical instruments.2

WHY IS IT IMPORTANT?

Store endoscopes and its accessories in a way that prevents recontamination, protects the instrument from damage and promotes drying.2

8. DOCUMENTATION

WHAT IS IT?

Maintain documentation of these steps each time an endoscope is reprocessed.2

WHY IS IT IMPORTANT?

Documentation is necessary for quality assurance purposes and for patient tracing if necessary.2

Disinfection and Sterilization – What’s the Difference?

Disinfection, including high-level disinfection, is crucial for reducing microbial load but does not guarantee complete eradication of all microorganisms. For the highest level of safety, sterilization—achieving a SAL of 10-6 with a significant margin of safety—ensures that medical and surgical instruments are entirely free of viable pathogens and provides superior protection against infection.

Disinfection icon

Disinfection:

A process that eliminates many or all pathogenic microorganisms, except bacterial spores, on inanimate objects. Disinfection is typically achieved through chemical agents or thermal methods and is classified into levels (high, intermediate, low) based on the effectiveness against various pathogens.

Sterilization icon

Sterilization:

A process that destroys or eliminates all forms of microbial life, including bacteria, viruses, fungi, and spores. Sterilization methods include steam under pressure (autoclaving), dry heat, ethylene oxide gas, and chemical sterilants.

Terminal Sterilization icon

Terminal Sterilization:

A process by which products are sterilized in their final packaging, ensuring that the item is completely sterile when it reaches the end user. Terminal sterilization is commonly used for medical devices and pharmaceuticals to guarantee their sterility until use.

Illustration of microbial life post-reprocessing

How to Determine Endoscope Reprocessing Modality

Determining the appropriate reprocessing modality will require an understanding of the Spaulding Classification of instrumentation. The Spaulding Classification defines the minimum levels of disinfection or sterilization that should be used according to the infection risk associated with a medical device.5

Critical Items:

Devices that enter sterile body sites or the bloodstream, where there is a high risk of infection if not properly sterilized.

Required Process:

Sterilization is required. This process eliminates all forms of microbial life, including bacterial spores. Methods include steam under pressure (autoclaving), dry heat, ethylene oxide gas, and other chemical sterilants.

Semi-Critical Items:

Devices that come into contact with mucous membranes or non-intact skin. They pose a moderate risk of infection.

Required Process:

High-Level Disinfection (HLD): This process destroys all microorganisms except bacterial spores. HLD is typically achieved using chemical disinfectants like glutaraldehyde, ortho-phthalaldehyde (OPA), or hydrogen peroxide.

Sterilization: This process is increasingly recommended as per ST91 guidelines to ensure the highest level of infection control. This is especially important for items that come into contact with mucous membranes or non-intact skin, where the risk of infection is significant. Using sterilization ensures the complete elimination of all microorganisms, including bacterial spores, providing enhanced safety and compliance with best practices.

Non-Critical Items:

Devices that come into contact only with intact skin. They pose a lower risk of infection compared to critical and semi-critical items.

Required Process:

Intermediate-Level Disinfection or Low-Level Disinfection is sufficient. Intermediate-level disinfection destroys most bacteria, most viruses, and most fungi, while low-level disinfection is effective against a wide range of bacteria, some viruses, and fungi but may not kill bacterial spores or resilient pathogens.

Critical Items:

Devices that enter sterile body sites or the bloodstream, where there is a high risk of infection if not properly sterilized.

Required Process:

Sterilization is required. This process eliminates all forms of microbial life, including bacterial spores. Methods include steam under pressure (autoclaving), dry heat, ethylene oxide gas, and other chemical sterilants.

Semi-Critical Items:

Devices that come into contact with mucous membranes or non-intact skin. They pose a moderate risk of infection.

Required Process:

High-Level Disinfection (HLD): This process destroys all microorganisms except bacterial spores. HLD is typically achieved using chemical disinfectants like glutaraldehyde, ortho-phthalaldehyde (OPA), or hydrogen peroxide.

Sterilization: This process is increasingly recommended as per ST91 guidelines to ensure the highest level of infection control. This is especially important for items that come into contact with mucous membranes or non-intact skin, where the risk of infection is significant. Using sterilization ensures the complete elimination of all microorganisms, including bacterial spores, providing enhanced safety and compliance with best practices.

Non-Critical Items:

Devices that come into contact only with intact skin. They pose a lower risk of infection compared to critical and semi-critical items.

Required Process:

Intermediate-Level Disinfection or Low-Level Disinfection is sufficient. Intermediate-level disinfection destroys most bacteria, most viruses, and most fungi, while low-level disinfection is effective against a wide range of bacteria, some viruses, and fungi but may not kill bacterial spores or resilient pathogens.

ASP Solutions

HIGH-LEVEL DISINFECTION

Institutions have several options for high-level disinfection of flexible endoscopes with biocide; manual soaking or automated reprocessing using an automated endoscope reprocessing (AER) system. All AER systems automate high-level disinfection, but some systems have additional features such as automated cleaning and automated leak testing. In addition, biocides monitoring is an important aspect with high-level disinfection reprocessing. ANSI AAMI ST91:2021 Flexible and semi-rigid endoscope reprocessing in health care facility recommends monitoring biocide Minimum Recommended Concentration (MRC) every cycle; MRC testing is typically performed with a manual test strip.6

STERILIZATION

According to researcher W.A. Rutala, PhD, MPH, CIC, “nearly all infections and patient exposures related to reprocessing medical or surgical instruments involve high-level disinfection (HLD) of reusable semi-critical items,” while “critical items are rarely, if ever, associated with disease transmission.” 

The STERRAD™ System, a low-temperature hydrogen peroxide gas plasma sterilization system, is increasingly favored by institutions seeking a reliable method to sterilize flexible endoscopes. Recently, ASP received FDA clearance for a new cycle on our flagship STERRAD™ 100NX Sterilizer with ALLClear™ technology, specifically designed to reprocess duodenoscopes using hydrogen peroxide gas plasma sterilization. 

The patented technology in the STERRAD NX™ System and STERRAD™ 100NX System delivers a concentrated load of hydrogen peroxide sterilant through long and narrow lumens, enabling the terminal sterilization of flexible endoscopes. Hundreds of flexible endoscopes from leading manufacturers such as PENTAX Medical, FujiFilm, Olympus, and KARL STORZ have been validated for use in STERRAD™ Systems. For an up-to-date list, visit the STERRAD™ Sterility Guide.

References

  1. U.S. Food & Drug Administration (FDA). Infections Associated with Reprocessed Duodenoscopes. https://www.fda.gov/medical devices/reprocessing-reusable-medical-devices/infections-associated-reprocessed-duodenoscopes. Accessed August 4, 2020.

  2. Centers for Disease Control and Prevention (CDC). Essential Elements of a Reprocessing Program for Flexible Endoscopes – Recommendations of the Healthcare Infection Control Practices Advisory Committee. Last updated: June 28, 2017.

  3. Centers for Disease Control and Prevention (CDC). Introduction, Methods, Definition of Terms -Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) https://www.cdc.gov/infectioncontrol/guidelines/disinfection/introduction.html. Accessed August 4, 2020.

  4. Lichtenstein D, Alfa MJ. Cleaning and Disinfecting Gastrointestinal Endoscopy Equipment. Clinical Gastrointestinal Endoscopy 2019: 32-50.e5.

  5. Centers for Disease Control and Prevention (CDC). A Rational Approach to Disinfection and Sterilization - Guideline for Disinfection and Sterilization in Healthcare Facilities (2008). https://www.cdc.gov/infectioncontrol/guidelines/disinfection/rational-approach.html. Accessed August 4, 2020.

  6. Association for the Advancement of Medical Instrumentation (2021). ANSI/AAMI ST91:2021. Flexible and semi-rigid endoscope processing in health care facilities.

  7. Ofstead CL, Hopkins KM, Buro BL, Eiland JE, Wetzler HP. Challenges in Achieving Effective High-Level Disinfection in Endoscope Reprocessing. Am J Infect Control 2019: 10.1016.

  8. Rutala WA, Weber DJ. Reprocessing semicritical ítems: Current issues of new technologies. Am J Infect Control 2016: 44 e53-62.

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