Flexible Endoscopes

Purpose

This document provides guidance for processing flexible endoscopes, including point-of-use treatment, leak testing, manual cleaning, cleaning verification, inspection, sterilization, high-level disinfection, drying, transport, and storage. Special considerations are addressed for performing microbiological surveillance of flexible endoscopes, using endoscope sheaths, and minimizing the risk for transmitting prion diseases from contaminated flexible endoscopes. Guidance is also provided for pre-purchase evaluation of reusable and single-use flexible endoscopes and related processing equipment. The recommendations are general recommendations; specific guidance for processing can be found in the US Food and Drug Administration (FDA)-cleared, manufacturer-validated instructions for use (IFU) for the flexible endoscope, accessories, processing equipment, chemicals, and supplies.

Outbreaks and pseudo-outbreaks of multidrug-resistant organisms (MDROs) and other pathogens (eg, Pseudomonas aeruginosa, Salmonella enteritidis, Mycobacterium abscessus) have been associated with the use of duodenoscopes,^1-24  gastroscopes,^25,26  colonoscopes,²⁷  bronchoscopes,^25,28-34  endobronchial ultrasound bronchoscopes,^29,35  ureteroscopes,^5,25,36-40  and cystoscopes.^5,25,36,41  Although many outbreaks have been linked to deficient processing practices, there have been outbreaks involving duodenoscopes in which the investigators did not identify any processing deviations.^{11,14,15,20-24}  However, some of the implicated duodenoscopes were found to be damaged upon inspection by the manufacturer.^20,21,24,42  The main concern raised by these outbreaks is whether current processing guidelines are adequate to ensure flexible endoscopes are safe for patients or whether their complex design, difficult cleaning processes, heavy microbial contamination, and presence of biofilm make it impossible to achieve high-level disinfection (HLD).⁴³ 

Flexible endoscopes are complex medical devices that require equally complex processes for effective cleaning and sterilization or HLD (Figure 1). 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. Because of complexity in the device design and the process, there is a narrow margin for safety when processing flexible endoscopes, especially when using HLD instead of terminal sterilization modalities. The FDA has called on the industry to improve device design to make endoscope processing easier, more effective, or unnecessary.⁴⁴  Those who process flexible endoscopes are advised to increase the emphasis on a quality management systems approach, including ongoing monitoring to ensure adequacy of cleaning.⁴⁵ 

Figure 1. Flexible Endoscope Processing Cycle

Guidance for the following topics is outside the scope of this document:

• processes for sterilization or HLD of flexible endoscopes that are not cleared by the FDA (eg, use of chlorine dioxide wipes);

• processing of flexible endoscopes and accessories that are labeled as single-use devices;

• facility design (See the AORN Guideline for Design and Maintenance of the Surgical Suite⁴⁶ ); and

• transport of flexible endoscopes to another facility (See the AORN Guideline for Sterilization⁴⁷ ).

Refer to the AORN Guideline for Care and Cleaning of Surgical Instruments,⁴⁸  Guideline for Manual Chemical High-Level Disinfection,⁴⁹  Guideline for Sterilization Packaging Systems,⁵⁰  and Guideline for Sterilization⁴⁷  for additional guidance related to decontamination, HLD, and sterilization processes.

Evidence Review

A medical librarian with a perioperative background conducted a systematic search of the databases Ovid MEDLINE, Ovid Embase, EBSCO CINAHL, and the Cochrane Database of Systematic Reviews. The search was limited to literature published in English from January 2015 through March 2021. At the time of the initial search, weekly alerts were created on the topics included in that search. Results from these alerts were provided to the lead author until February 2022. The lead author requested additional articles that either did not fit the original search criteria or were discovered during the evidence appraisal process. The lead author and the medical librarian also identified relevant guidelines from government agencies, professional organizations, and standards-setting bodies.

Search terms included access to health care, acetic acid, advanced sterilization products, Ambu, allergic reaction, allergy, automated endoscope reprocessor, availability of health services, bacterial adhesion, biocide, biofilms, biofoul, borescope, Boston Scientific, bronchoscopes, CaviCide, chemical safety, chemical safety measures, chlorine dioxide wipes, cholangiopancreatography (endoscopic retrograde), Cidex, Circon-Gyrus ACMI, cleaning verification, cleansing agents, colonoscopes, cross infection, cystoscopes, decontamination, detergents, disinfectants, disinfection, drying cabinet, duodenoscopes, duodenoscopy, elevator channel, elevator mechanism, endoscope sheath, endobronchial ultrasound bronchoscope, endoscope storage, endoscope tip protector, endoscopes, endoscopic retrograde cholangiopancreatography, endoscopic surgical procedures, endoscopic ultrasound scope, endoscopy, ENT endoscopes, enzymatic detergents, equipment contamination, ERCP scope, flexible bronchoscop*, flexible colonoscop*, flexible cystoscop*, flexible duodenoscop*, flexible endoscop*, flexible gastroscop*, flexible hysteroscop*, flexible laryngoscop*, flexible ureteroscop*, fomites, Fuijinon, gastroscopes, glutaraldehyde, glutaral, health care associated infection, health care inequalities, health services accessibility, health services availability, health services needs and demand, healthcare associated infection, healthcare disparities, helicobacter infections, Helicobacter pylori, high-level disinfection, hospital infections, hypersensitivity, hysteroscopes, infection control, instrument air, instrument disinfectant, ionized water, laryngoscopes, leak detection, leak test, magnification, mechanical processor, medically underserved area, medically underserved population, Medivator, natural orifice endoscopic surgery, natural orifice transluminal endoscopy, nosocomial infection, occupational exposure, occupational hazards, occupational safety, Olympus, Pentax, Phazyme 125, physician shortage area, protective clothing, protein test, racial disparities, reprocessing, Richard Wolf, Scope Buddy, scope sheath, simethicone, social determinants of health, Spaulding, sterile water, sterilization, sterilization and disinfection, Steris, storage cabinet, storage sheath, Storz, surgical endoscopy, underserved patients, underserved population, ureteroscopes, video laryngoscope, washer disinfector, washing system, water microbiology, and water supply.

Included were research and non-research literature in English, complete publications, and publications with dates within the time restriction when available. Excluded were non-peer-reviewed publications, editorials, and news items. Low-quality evidence was excluded when higher-quality evidence was available, and literature outside the time restriction was excluded when literature within the time restriction was available (Figure 2).

Figure 2. Flow Diagram of Literature Search Results

Adapted from Moher D, Liberati A, Tetzlaff J, Atman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA Statement. PLoS Med. 2009;6(6):e1000097.

Articles identified in the search were provided to the project team for evaluation. The team consisted of the lead author and one evidence appraiser. The lead author and the evidence appraiser reviewed and critically appraised each article using the AORN Research or Non-Research Evidence Appraisal Tools as appropriate. A second appraiser was consulted in the event of a disagreement between the lead author and the primary evidence appraiser. The literature was independently evaluated and appraised according to the strength and quality of the evidence. Each article was then assigned an appraisal score. The appraisal score is noted in brackets after each reference as applicable.

Each recommendation rating is based on a synthesis of the collective evidence, a benefit-harm assessment, and consideration of resource use. The strength of the recommendation was determined using the AORN Evidence Rating Model and the quality and consistency of the evidence supporting a recommendation. The recommendation strength rating is noted in brackets after each recommendation.

Note: The evidence summary table is available at https://www.aorn.org/guidelines/about-aorn-guidelines/evidence-rating.