Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video)

A New Drying Method of Thermolabile Flexible Endoscope Channels by Laminar and Turbulent Airflow: A Prospective, Randomized-Controlled, Single-Center, Proof-of-Concept Trial

INTRODUCTION

International guidelines suggest different possibilities for drying of endoscopes during reprocessing. Clinical results of these available drying methods are not satisfactory. The aim of this study was to compare the drying cycle of a standard endoscope washer-disinfector (EWD) (standard drying method [SD]) with a shortened mandatory drying by the EWD followed by a special drying device using laminar and turbulent air flow (novel drying method [ND]).

METHODS

Sixty endoscopes (duodenoscopes, colonoscocopes, and gastroscopes) from 3 different manufacturers underwent high-level disinfection and drying depending on the randomization group. Operational time of drying was measured for both groups. Residual fluid in the channels was measured using a laboratory scale. After a 14-day storage period, a sample of the endoscope channels was obtained to determine bacterial contamination.

RESULTS

ND had significantly fewer residual water in endoscope channels (SD: 90% vs ND: 0%; P < 0.001) after high-level disinfection and drying and less bacterial contamination after storage for 14 days (SD: 47% vs ND: 20%; P = 0.028). Time consumed for drying in ND was also significantly shorter (SD: 16 minutes 4 seconds vs ND: 5 minutes 59 seconds; P < 0.001).

DISCUSSION

Drying with a special automatic drying device was superior compared with an EWD's drying program as evidenced by no measurable residual water, reduced microbiological contamination, and a more than 2-fold decrease in operational time. Thus, drying by laminar and turbulent airflow may represent an attractive alternative to the currently used standard approach in the reprocessing process of flexible endoscopes.

Multisociety guidance for sterilization and high-level disinfection

SHEA, in partnership with ASGE, APIC, AAMI, AORN, HSPA, IDSA, SGNA, and The Joint Commission, developed this multisociety infection prevention guidance document for individuals and organizations that engage in sterilization or high-level disinfection (HLD). This document follows the CDC Guideline for Disinfection and Sterilization in Healthcare Facilities. This guidance is based on a synthesis of published scientific evidence, theoretical rationale, current practices, practical considerations, writing group consensus, and consideration of potential harm when applicable. The supplementary material includes a summary of recommendations. The guidance provides an overview of the Spaulding Classification and considerations around manufacturers' instructions for use (MIFUs). Its recommendations address: point-of-use treatment prior to sterilization or HLD, preparation of reusable medical devices at the location of processing, sterilization, and immediate use steam sterilization (IUSS), HLD of lumened and non-lumened devices, processing of reusable medical devices used with lubricating or defoaming agents, monitoring for effectiveness of processing, handling of devices after HLD, augments and alternatives to HLD, processing of investigational devices, tracking of reusable medical devices, and approaches to implementation.

Impact of Different Pressures on the Drying Time of Flexible Endoscopes

BACKGROUND

The complex structure of endoscopes causes nonuniform drying conditions. However, current clinical drying practices lack precise guidance, leading to the insufficient drying of some endoscopes, which increases the risk of infection. The pressure of compressed air has been proven to affect the effectiveness of endoscope drying; however, specific requirements are absent. This study explored the time required for the sufficient drying of different endoscopes under various pressure conditions.

METHODS

Six different types of commonly used Olympus flexible endoscopes were selected, and for each type, multiple drying time groups were set under pressures of 0.102 and 0.204 MPa, with 10 endoscopes observed in each group.

RESULTS

Drying times varied according to the type and pressure. At 0.102 MPa, the instrument channel drying ranged from 80 s to 160 s (avg. 123 s), while suction channel ranged from 260 s to 540 s (avg. 428 s). At 0.204 MPa, the instrument channel dried in 50 s to 90 s (avg. 72 s), and suction channel in 130 s to 230 s (avg. 186 s).

CONCLUSIONS

Optimal drying times for endoscopes differ according to the type and pressure. A higher pressure (0.204 MPa) efficiently removes moisture and speeds up drying. Longer endoscopes with the same biopsy channel diameter require longer drying time. In addition, the instrument channel dries faster than the suction channel.

Impact of Borescope Inspections on Endoscope Repair Frequency and Costs

Background: Infections and injuries have been linked to endoscopes with visible damage or residue. Guidelines recommend visual inspection to identify endoscopes requiring repair or further cleaning. This study sought to evaluate the impact of routine borescope inspections on repair frequency and costs. Methods: Retrospective analysis was performed on a database of endoscope repairs compiled for a three-year period by a large academic medical center that began performing borescope inspections for every endoscope after manual cleaning. Endpoints included total number of repairs, total repair cost, mean cost per repair, mean turnaround time per repair, and procedural usage between repairs. Subgroup analysis was performed to identify repair patterns by endoscope type. Results: The total cost of repairs decreased from $1,212,702 in 2022 to $724,419 in 2024. The number of repairs required annually was similar over time, but reductions occurred in the proportion of repairs classified as major (12.1% to 3.2%) and the mean cost per repair ($4,426 to $2,337; P < 0.001). Mean turnaround time for repairs decreased (from 24.1 to 15.5 days; P < 0.001). Mean number of uses between repairs increased over time (from 52.1 to 87.2; P < 0.001), and the facility decreased the size of the endoscope fleet from 593 to 508. Conclusion: Significant reductions in endoscope repair frequency and cost occurred over time in a large, centralized endoscope processing department that performed borescope inspections of every endoscope after manual cleaning.

Efficacy of spray flushing in the reprocessing of flexible endoscopes: A randomized controlled trial

BACKGROUND

Commonly used cleaning brushes in the reprocessing of flexible endoscopes often cause damage within the working channels.

AIM

To develop a spray flushing system to achieving effective cleaning of the working channels while minimizing damage.

METHODS

This prospective study included 60 used endoscopes and 60 Teflon tubes randomly divided into a control group (n = 30) and an experimental group (n = 30). The material of Teflon tubes was the same as that of the endoscope working channel. Endoscopes in the control group were manually cleaned using traditional cleaning brushes, while those in the experimental group were cleaned using the newly developed spray flushing system. ATP levels, cleanliness, and microbiological testing of the working channels were measured. Additionally, Teflon tubes in the control group underwent 500 passes with a cleaning brush, while those in the experimental group were subjected to the spray flushing system, and channel damage was evaluated.

RESULTS

The ATP levels (RLU) in the two groups were 32.5 (13-66) and 26 (16-40), respectively (P > 0.05). Cleanliness scores were 1.5 (1-2) and 1 (1-2), respectively (P > 0.05). Debris was found in 73.3% of the control group, which was significantly higher than 46.7% in the experimental group (P < 0.05). Microbiological tests for both groups yielded negative results. Teflon tube damage in the control group was rated at 4 (4-5.25), which was significantly higher than in the experimental group 4 (3-4) (P < 0.01).

CONCLUSION

The spray flushing system demonstrated superior efficacy in removing debris and resulted in less damage to the endoscope working channels compared with traditional cleaning brushes.

Use of whole genomic sequencing to detect New Delhi metallo-B-lactamase (NDM)-producing Escherichia coli outbreak associated with endoscopic procedures

BACKGROUND

Whole-genome sequencing (WGS) has emerged as an alternative genotyping tool for outbreak investigations in the healthcare setting. We describe the investigation and control of a New Delhi metallo-B-lactamase (NDM)-producing Escherichia coli cluster in Southeast Michigan.

METHODS

Michigan Bureau of Laboratories identified several closely related NDM-producing E. coli isolates with WGS. An epidemiologic investigation, including case-control study, assessment of infection control practices, and endoscope culturing, was performed to identify source of transmission. Targeted screening of potentially exposed patients was performed following identification of probable source.

RESULTS

Between July 2021 and February 2023, nine patients were identified. Phylogenetic analysis confirmed the isolates were closely related with less than 26 single nucleotide polymorphism (SNP) differences between isolates, suggesting an epidemiological link. Eight (89%) patients had a duodenoscope and/or gastroscope exposure. Cases were compared with 23 controls. Cases had significantly higher odds of exposure to duodenoscopes (odds ratio 15.0; 95% CI, 1.8-142.2; P = .015). The mean incubation period, estimated as date of procedure to positive index culture, was 86 days (range, 1-320 days). No lapses in endoscope reprocessing were identified; NDM-producing E. coli was not recovered from reprocessed endoscopes or during targeted screening. No additional cases were identified after removal of implicated gastroscopes and replacement of duodenoscope with disposable end caps.

CONCLUSIONS

In this investigation, WGS was utilized to identify transmission of an NDM-producing E. coli outbreak associated with endoscope exposure. Coupled with epidemiologic data, WGS can facilitate outbreak investigations by rapidly identifying linked cases and potential sources to prevent further transmission.

A search strategy for detecting duodenoscope-associated infections: a retrospective observational study

BACKGROUND

Duodenoscope-associated infections (DAIs) are exogenous infections resulting from the use of contaminated duodenoscopes. Though numerous outbreaks of DAI have involved multidrug-resistant micro-organisms (MDROs), outbreaks involving non-MDROs are also likely to occur. Detection challenges arise as these infections often resolve before culture or because causative strains are not retained for comparison with duodenoscope strains.

AIM

To identify and analyse DAIs spanning a seven-year period in a tertiary care medical centre.

METHODS

This was a retrospective observational study. Duodenoscope cultures positive for gastrointestinal flora between March 2015 and September 2022 were paired with duodenoscope usage data to identify patients exposed to contaminated duodenoscopes. Analysis encompassed patients treated after a positive duodenoscope culture and those treated within the interval from a negative to a positive culture. Patient identification numbers were cross-referenced with a clinical culture database to identify patients developing infections with matching micro-organisms within one year of their procedure. A 'pair' was established upon a species-level match between duodenoscope and patient cultures. Pairs were further analysed via antibiogram comparison, and by whole-genome sequencing (WGS) to determine genetic relatedness.

FINDINGS

Sixty-eight pairs were identified; of these, 21 exhibited matching antibiograms which underwent WGS, uncovering two genetically closely related pairs categorized as DAIs. Infection onset occurred up to two months post procedure. Both causative agents were non-MDROs.

CONCLUSION

This study provides crucial insights into DAIs caused by non-MDROs and it highlights the challenge of DAI recognition in daily practice. Importantly, the delayed manifestation of the described DAIs suggests a current underestimation of DAI risk.

Recommendations and guidelines for endoscope reprocessing: Current position statement of digestive endoscopic society of Taiwan

Reprocessing of gastrointestinal (GI) endoscopes and accessories is an essential part of patient safety and quality control in GI endoscopy centers. However, current endoscopic reprocessing guidelines or procedures are not adequate to ensure patient-safe endoscopy. Approximately 5.4 % of the clinically used duodenoscopes remain contaminated with high-concern microorganisms. Thus, the Digestive Endoscopy Society of Taiwan (DEST) sets standards for the reprocessing of GI endoscopes and accessories in endoscopy centers. DEST organized a task force working group using the guideline-revision process. These guidelines contain principles and instructions of step-by-step for endoscope reprocessing. The updated guidelines were established after a thorough review of the existing global and local guidelines, systematic reviews, and health technology assessments of clinical effectiveness. This guideline aims to provide detailed recommendations for endoscope reprocessing to ensure adequate quality control in endoscopy centers.

Unveiling 8 years of duodenoscope contamination: insights from a retrospective analysis in a large tertiary care hospital

OBJECTIVE

Contaminated duodenoscopes caused several hospital outbreaks. Despite efforts to reduce contamination rates, 15% of patient-ready duodenoscopes are still contaminated with gastrointestinal microorganisms. This study aimed to provide an overview of duodenoscope contamination over time, identify risk factors and study the effects of implemented interventions.

DESIGN

Duodenoscope culture sets between March 2015 and June 2022 at a Dutch tertiary care centre were analysed. Contamination was defined as (1) the presence of microorganisms of oral or gastrointestinal origin (MGO) or (2) any other microorganism with ≥20 colony-forming units/20 mL (AM20). A logistic mixed effects model was used to identify risk factors and assess the effect of interventions, such as using duodenoscopes with disposable caps, replacing automated endoscope reprocessors (AER) and conducting audits in the endoscopy department.

RESULTS

A total of 404 culture sets were analysed. The yearly contamination rate with MGO showed great variation, ranging from 14.3% to 47.5%. Contamination with AM20 increased up to 94.7% by 2022. For both MGO and AM20, the biopsy and suction channels were the most frequently contaminated duodenoscope components. The studied interventions, including audits, AER replacement and implementation of duodenoscopes with disposable caps, did not show a clear association with contamination rates.

CONCLUSION

Duodenoscope contamination remains a significant problem, with high contamination rates despite several interventions. Reprocessing the biopsy and suction channels is especially challenging. Changes in the design of reusable duodenoscopes, such as enabling sterilisation or easily replaceable channels, are necessary to facilitate effective duodenoscope reprocessing and to eliminate the risk of duodenoscope-associated infections.

Beyond Endoscopes: Pilot Study of Surgical Instrument Lumen Inspection

Objective: Borescope examinations of endoscope channels are commonly described in literature, but no studies on surgical instrument lumen inspection have been published recently. Inadequately processed surgical instruments have been implicated in patient infections. This study assessed the utility of borescopes for inspecting surgical instruments. Methods: The study team inspected and photographed sterilized, patient-ready arthroscopic shaver handpieces and suction tips using a tablet camera and borescopes to characterize internal anatomy, defects found in lumens, and the impact of recleaning on debris or residues. Results: Ten suctions and eight shavers were inspected. All suctions had internal ridges and suction holes that were perpendicular to the lumen. All shavers had visible ridges, elbows, and lever mechanisms inside lumens. Of the 18 instruments, 16 (88%) had internal features that appeared rough or jagged and 17 (94%) had visible debris or discoloration in the lumens. Recleaning efforts generally were effective for suctions, but multiple rounds of recleaning with enhanced steps were less effective for shavers, which were replaced. Researchers documented retained soil and brush bristles in several new shavers despite following manufacturer instructions for cleaning and found visible damage and discoloration within five uses. Discussion: This study demonstrated the value of borescope examinations for surgical instrument lumens. Visual inspections identified anatomical features that could influence cleaning effectiveness and detected residual soil, discoloration, and debris in most instruments. The findings suggested that manufacturer cleaning instructions were insufficient and additional cleaning was not always effective. In response, the site's multidisciplinary team strengthened risk assessment protocols and enhanced their cleaning practices.

Assessment of endoscope reprocessing at World Gastroenterology Organisation training centers using adenosine triphosphate testing

Background and study aims Adequacy of endoscope disinfection in resource-limited settings is unknown. Adenosine triphosphate (ATP) testing is useful for evaluation of endoscope reprocessing, and ATP <200 relative light units (RLUs) after manual endoscope cleaning has been associated with adequacy of endoscope disinfection. Methods Consecutive endoscopes undergoing reprocessing at five World Gastroenterology Organisation (WGO) training centers underwent ATP testing before and after an on-site educational intervention designed to optimize reprocessing practices. Results A total of 343 reprocessing cycles of 65 endoscopes were studied. Mean endoscope age was 5.3 years (range 1-13 years). Educational interventions, based on direct observation of endoscope reprocessing practices at each site, included refinements in pre-cleaning, manual cleaning, high-level disinfection, and endoscope drying and storage. The percentage of reprocessing cycles with post-manual cleaning ATP ≧200 decreased from 21.4% prior to educational intervention to 14.8% post-intervention ( P =0.11). In multivariable logistic modelling, gastroscopes were significantly less likely (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.01-0.19; P <0.001) than colonoscopes to achieve post-manual cleaning ATP < 200. No other factor (educational intervention, study site, endoscope age) was significantly associated with improved outcomes. Endoscope ID was not significantly associated with ATP values, and sites that performed manual versus automated HLD did not have significantly different likelihood of post-manual cleaning ATP <200 (OR 1.18, 95% CI 0.56-2.50; P =0.67). Conclusions In resource-limited settings, approximately 20% of endoscope reprocessing cycles may result in inadequate disinfection. This was not significantly improved by a comprehensive educational intervention. Alternative approaches to endoscope reprocessing are needed.

What Are the Ready-to-Use Endoscope Channels Hiding?: Unraveling the Risks of Safe Reuse

Contamination due to failures or omissions in the reprocessing steps of gastrointestinal endoscopes is common in clinical practice. Ensuring the proper execution of each step is a challenge for reprocessing personnel. This cross-sectional study was conducted in an endoscopy setting between March and May 2021. We performed interviews about reprocessing practices, analyzed the life history of the equipment, and performed inspections through a borescope video of gastrointestinal endoscope channels that were stored and ready for use. A borescope is a complementary tool used to validate endoscope reprocessing, evaluate the internal visualization of channels, and identify changes that can compromise the safety of its use, which are often not detected in the leak test. Thirteen biopsy channels from stored gastrointestinal endoscopes were inspected. We found that 85% had stains and grooves, 69% contained moisture, and 46% had debris. There was at least one noncompliance issue in all of the channels inspected.

Clinical Evaluation of Miniature Flexible Scope for Diagnosis of Ureteroscope Working Channel Defects

Introduction: To evaluate flexible ureteroscope working channels with a 1.06 mm digital borescope (Clarus Medical, Minneapolis, MN) and identify factors contributing to ureteroscope damage over time. Materials and Methods: We performed a single institutional prospective study of patients undergoing stone surgery using a nondisposable flexible ureteroscope. A 1.06 mm borescope was used to evaluate ureteroscopes before and after surgery. Borescope videos were reviewed by two independent researchers to quantify average pre- and postprocedural damage. Results: Twenty-five procedures were performed with pre- and postprocedural borescope assessment between August 2021 and February 2022. All patients received preoperative CT imaging depicting a mean axial stone size of 14.1 ± 8.4 mm and density of 923.4 ± 458.1 HU. Mean operative time was 63.8 ± 34.0 minutes. The average number an instrument passes through the working channel was 2.1 ± 1.6. Laser was used in 11 cases with mean laser time of 18.8 ± 19.7 minutes and mean total energy of 5.8 ± 4.2 KJ. On preoperative assessment, all ureteroscopes had some form of defect (24% shave, 32% pinhole, 96% dents and scratches, and 28% discolorations). During postoperative assessment, 23/25 (92%) ureteroscopes showed additional damage with an average of 3.7 ± 2.8 imperfections acquired after one use. Significant differences were seen in acquired shavings (p = 0.028) and scratches or dents (p = 0.018). Of the 355 imperfections seen on postoperative evaluation, 0.4% were shave, 3% were pinhole, 85.8% were dents and scratches, and 10.8% were discolorations. Conclusion: The Clarus borescope observed defects after the majority of flexible ureteroscopy procedures for nephrolithiasis. Although such disruptions may not immediately render ureteroscopes nonfunctional, they are more common than previously described and could increase maintenance costs. Further studies are needed to investigate the burden of unit damage per procedure to raise operator awareness and reduce preventable ureteroscope imperfections.

Improving mastery and retention of knowledge and complex skills among sterile processing professionals: A pilot study on borescope training and competency testing

BACKGROUND

Healthcare is shifting toward minimally invasive procedures requiring increasingly complex instruments and sophisticated processing technologies. Effective training methods are needed to ensure sterile processing professionals acquire and retain essential skills.

OBJECTIVE

This study aimed to develop and evaluate a new training model that supports mastery and retention of complex key skills.

METHODS

The model was pilot-tested with training focused on visual inspection of endoscopes. Pre- and post-training tests were administered to enhance learning during a face-to-face workshop that interspersed lectures and hands-on practice, followed by structured homework, and an online booster session. Surveys assessed satisfaction and confidence levels.

RESULTS

Mean test scores for nine certified sterile processing employees increased significantly following the workshop (41% vs. 84%, p<0.001). After the workshop, all trainees identified actionable visible defects on patient-ready endoscopes in their facilities. Test scores remained high after two months (90%), and trainees reported higher technical confidence and satisfaction levels after training.

CONCLUSIONS

This study demonstrated effectiveness and clinical relevance of a new, evidence-based model for training sterile processing professionals that incorporated pre-testing, lectures, hands-on practice, a training booster, and post-testing to enhance learning. This model may be applicable to other complex skills necessary for infection prevention and patient safety.

How effective are the alcohol flush and drying cycles of automated endoscope reprocessors? Stripped endoscope model

BACKGROUND

Effective drying of the internal channels of endoscopes is essential to prevent the growth of water-borne pathogens and to assure adequate sterilization with vaporized hydrogen peroxide or ethylene oxide. The aim of this study was to evaluate the dryness of endoscopes after a routine disinfection process in an automated endoscope reprocessor.

METHODS

Stripped endoscopes (SE) that allow for visual inspection of the inside channels were reprocessed per protocol in a large urban medical center, with a 3-minute or 10-minute air flush following reprocessing. SE was hung and observed for any water within the channels after reprocessing and after a week of ambient storage. Ready-for-use endoscopes were also randomly spot-checked for moisture visually and with moisture detection paper.

RESULTS

All SE were grossly wet after HLD with a 3-minute air flush, despite alcohol flush and drying cycle. The 10-minute air flush was effective at drying the biopsy/suction channel, but not the air/water channels. Hanging had limited effect, being most effective in the biopsy/suction channels. Of the 77 ready-for-use respiratory and gastrointestinal endoscopes assessed, 37 (48.1%) showed evidence of retained moisture.

CONCLUSIONS

Air flush cycles commonly used in the final steps of automated endoscope reprocessing may not adequately dry endoscope channels, particularly the narrower diameter air/water channels. An extended 10-minute air flush appears effective at drying the larger biopsy/suction channel, but has limited effect on the air/water channels.

Investigation of the Internal Conditions of 213 Reprocessed Endoscopic Channels

BACKGROUND AND AIMS

Studies have indicated that endoscope reprocessing failure might be attributed to internal damage or residual liquid in endoscopes. However, large-sample survey data on the internal conditions of endoscopic channels after reprocessing are lacking. This study used a borescope to investigate the internal cleanliness and damage of 213 endoscopic biopsy channels after reprocessing at the endoscopy center of the First Affiliated Hospital of Nanchang University, provided in theoretical basis for the efficacy of endoscope reprocessing and maintenance.

METHODS

A borescope was used to observe and analyze the inside of the endoscopic biopsy channel of 213 reprocessed endoscopes (in accordance with the Chinese health industry standard "Regulation for cleaning and disinfection technique of flexible endoscope (WS 507-2016). Each endoscope was observed for at least 10 minutes, and the results were recorded and evaluated by 5 researchers independently.

RESULTS

In all, 2504 images and 109 videos were recorded, and abnormal findings were classified into 10 categories: scratches (91.5%, 195/213), scratches with adherent peel (46.0%, 98/213), discolored areas (49.3%, 105/213), transparent drops (28.2%, 60/213), milky drops (23.9%, 51/213), white particles (46.9%, 100/213), attached materials (37.6%, 80/213), wear on metal parts (41.3%, 88/213), rust (23.9%, 51/213), and black spots (35.7%, 76/213). Among scratches, those in Teflon from 0-10 cm at the apex of the biopsy channel outlet and in metal from 0-5 cm at the biopsy channel inlet accounted for 58.4% (114/195) and 96.4% (188/195), respectively.

CONCLUSIONS

Scratches were the most common form of damage in the endoscopic biopsy channels investigated and were related to the use of endoscopic accessories and cleaning brush materials. The incidence of other abnormalities gradually increased with the duration of use and began to increase significantly after 18 months. All abnormalities have a certain impact on the quality of endoscope reprocessing. We recommend that a borescope be used to check the inside of endoscopic biopsy channels regularly to determine the damage and cleaning conditions and that these channels be reprocessed, repaired, or replaced in a timely manner.

The utility of lighted magnification and borescopes for visual inspection of flexible endoscopes

INTRODUCTION

Infections have been linked to damaged or contaminated endoscopes with visible defects. Endoscope processing standards and guidelines state endoscopes should be visually inspected every time they are used. This study evaluated a new visual inspection program using magnification and borescopes in an endoscopy department that had not previously utilized these tools.

METHODS

Site personnel were given visual inspection tools and training before systematically examining fully processed endoscopes twice during a 2-month period. A risk assessment protocol was used to determine whether endoscopes required recleaning, repair, or other action. Findings were documented using log sheets, photographs, and videotapes.

RESULTS

Visible damage and residue or debris were observed in 100% of 25 endoscopes at both assessments, and 76% required repair. Defects at baseline included scratches (88%); channel shredding or peeling (80%); adhesive band disintegration (80%); residual soil or debris (white 84%; black 68%; brown 40%; yellow/green 36%; and orange/red 8%); retained fluid (52%); and dents (40%). Findings were similar at follow-up.

DISCUSSION/CONCLUSIONS

Visual inspection with magnification and borescopes identified actionable defects that could interfere with processing effectiveness in 100% of endoscopes. Infection preventionists have a critical role to play in supporting processing personnel now that standards, guidelines, and manufacturer instructions recommend enhanced visual inspection of every endoscope, every time.

High Prevalence Rate of Microbial Contamination in Patient-Ready Gastrointestinal Endoscopes in Tehran, Iran: an Alarming Sign for the Occurrence of Severe Outbreaks

An alarmingly increasing number of outbreaks caused by contaminated gastrointestinal (GI) endoscopes are being reported as a particularly concerning issue. This study is the first large-scale multicenter survey to evaluate the contamination of GI endoscopes in Tehran, Iran. This multicenter study was conducted among 15 tertiary referral and specialized gastrointestinal settings. Reprocessed GI endoscopes were sampled by the sequence of the flush-brush-flush method. Bacterial and viral contamination, as well as antimicrobial resistance, were explored by culture and molecular assays. A total of 133 reprocessed and ready-to-use GI endoscopes were investigated. In phase I and phase II, 47% and 32%, respectively, of the GI endoscopes were determined to be contaminated. GI flora was the most prevalent contaminant isolated from GI endoscopes, in which the most predominant bacteria were Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, in both phase I and II evaluations. The majority of the isolated bacteria in the current study were considered multidrug-resistant organisms (MDROs). More importantly, we recovered carbapenem-resistant nonfermentative Gram-negative bacilli (CRNFGNB), carbapenem-resistant Enterobacterales (CRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E), multidrug-resistant Clostridioides difficile, vancomycin-resistant Enterococcus (VRE), and drug-resistant Candida spp. Disconcertingly, our molecular assays revealed contamination of some reprocessed GI endoscopes with hepatitis B virus (HBV), hepatitis C virus (HCV), and even HIV. This multicenter study indicates a higher-than-expected contamination rate among reprocessed and ready-for-patient-use GI endoscopes, which suggests a higher-than-expected endoscopy-associated infection (EAI) risk, and potentially, morbidity and mortality rate, associated with endoscopy procedures in Tehran, Iran. IMPORTANCE In the light of severe outbreaks caused by multidrug-resistant microorganisms due to contaminated GI endoscopes, understanding to what extent GI endoscopes are inadequately reprocessed is crucial. Several studies assessed contamination of GI endoscopes with various outcomes across the world; however, the prevalence and risk factors of contaminated GI endoscopes and potential subsequent nosocomial spread are still unknown in Iran. The present study is the first large-scale multicenter survey to evaluate the microbial contamination of repossessed and ready-to-use GI endoscopes in Tehran, Iran. Our study showed a higher-than-expected contamination rate among reprocessed GI endoscopes, which suggests potential seeding of deadly but preventable outbreaks associated with endoscopy procedures in Iran. These results suggest that the current reprocessing and process control guidelines do not suffice in Iran. The current study is of particular importance and could provide insights into unrecognized and unidentified endoscopy-associated outbreaks in Iran.

Efficacy of a novel channel-cleaning ball brush for endoscope reprocessing: a randomized controlled trial

Background/Aims

Endoscopic channels are difficult to clean and can cause infection transmission. We examined the effectiveness of a newly developed channel-cleaning ball brush (BB), which is sucked into the endoscopic channel and scrapes and cleans the lumen as it passes through.

Methods

The upper and lower gastrointestinal endoscopes used for patient examinations were randomly selected as the conventional brush (CB) or BB group. After manual cleaning, the presence or absence of carbohydrates, proteins, adenosine triphosphate, and hemoglobin was assessed.

Results

Fifty-six and 58 endoscopes were cleaned with the CB and BB, respectively. Carbohydrate and protein were detected in one (1.8%) and two endoscopes (3.4%) in the CB and BB groups, respectively (p=1.000). Hemoglobin was observed in one (1.8%) and three endoscopes (5.2%) in the CB and BB groups, respectively (p=0.636). The adenosine triphosphate levels were 10.6±15.9 and 12.5±14.3 relative light units in the CB and BB groups, respectively (p=0.496). Twenty-seven (48.2%) and 19 (32.8%) endoscopes were positive for microbial cultures in the CB and BB groups, respectively (p=0.136).

Conclusions

The efficacy of BB was not significantly different from that of CB in the endoscopic channel-cleaning process.

Initial application of deep learning to borescope detection of endoscope working channel damage and residue

Background and study aims  Outbreaks of endoscopy-related infections have prompted evaluation for potential contributing factors. We and others have demonstrated the utility of borescope inspection of endoscope working channels to identify occult damage that may impact the adequacy of endoscope reprocessing. The time investment and training necessary for borescope inspection have been cited as barriers preventing implementation. We investigated the utility of artificial intelligence (AI) for streamlining and enhancing the value of borescope inspection of endoscope working channels. Methods  We applied a deep learning AI approach to borescope inspection videos of the working channels of 20 endoscopes in use at our academic institution. We evaluated the sensitivity, accuracy, and reliability of this software for detection of endoscope working channel findings. Results  Overall sensitivity for AI-based detection of borescope inspection findings identified by gold standard endoscopist inspection was 91.4 %. Labels were accurate for 67 % of these working channel findings and accuracy varied by endoscope segment. Read-to-read variability was noted to be minimal, with test-retest correlation value of 0.986. Endoscope type did not predict accuracy of the AI system ( P  = 0.26). Conclusions  Harnessing the power of AI for detection of endoscope working channel damage and residue could enable sterile processing department technicians to feasibly assess endoscopes for working channel damage and perform endoscope reprocessing surveillance. Endoscopes that accumulate an unacceptable level of damage may be flagged for further manual evaluation and consideration for manufacturer evaluation/repair.

A narrative review on current duodenoscope reprocessing techniques and novel developments

Duodenoscopy-associated infections occur worldwide despite strict adherence to reprocessing standards. The exact scope of the problem remains unknown because a standardized sampling protocol and uniform sampling techniques are lacking. The currently available multi-society protocol for microbial culturing by the Centers for Disease Control and Prevention, the United States Food and Drug Administration (FDA) and the American Society for Microbiology, published in 2018 is too laborious for broad clinical implementation. A more practical sampling protocol would result in increased accessibility and widespread implementation. This will aid to reduce the prevalence of duodenoscope contamination. To reduce the risk of duodenoscopy-associated pathogen transmission the FDA advised four supplemental reprocessing measures. These measures include double high-level disinfection, microbiological culturing and quarantine, ethylene oxide gas sterilization and liquid chemical sterilization. When the supplemental measures were advised in 2015 data evaluating their efficacy were sparse. Over the past five years data regarding the supplemental measures have become available that place the efficacy of the supplemental measures into context. As expected the advised supplemental measures have resulted in increased costs and reprocessing time. Unfortunately, it has also become clear that the efficacy of the supplemental measures falls short and that duodenoscope contamination remains a problem. There is a lot of research into new reprocessing methods and technical applications trying to solve the problem of duodenoscope contamination. Several promising developments such as single-use duodenoscopes, electrolyzed acidic water, and vaporized hydrogen peroxide plasma are already applied in a clinical setting.

Sans Standardization: Effective Endoscope Reprocessing

Bronchoscopy is a commonly performed procedure within thoracic and critical care medicine. Modern bronchoscopes are technologically advanced tools made of fragile electronic components. Their design is catered to allow maximum maneuverability within the semi-rigid tracheobronchial tree. Effective cleaning and reprocessing of these tools can be a challenge. Although highly functional, the design poses several challenges when it comes to reprocessing. It is a very important step, and lapses in the procedure have been tied to nosocomial infections. The process lacks universal standardization; several organizations have developed their own recommendations. Data have shown that key stakeholders are not fully versed in the essentials of endoscope reprocessing. A significant knowledge gap exists between those performing bronchoscopy and those who are stewards of effective endoscope reprocessing. To service as a resource for bronchoscopists, this study summarizes the steps of effective reprocessing, details the important elements within a health-care facility that houses this process, and reviews some of the current data regarding the use of disposable endoscopes.

Two novel protocols for cleaning residual simethicone and fluid in patient-ready duodenoscopes

BACKGROUND AND AIM

Approximately 42-95% of working channels have been reported to show the presence of residual fluid despite endoscope reprocessing. The aim of this study was to design two novel protocols for cleaning residual simethicone and demonstrate its efficiency by evaluating the residual fluid and cleanliness in the working channels of patient-ready duodenoscopes.

METHODS

The designed protocol for cleaning residual simethicone was implemented in manual cleaning and/or high-level disinfection (HLD). The residual fluid inside the working channels was estimated by visual inspection. Adenosine triphosphate (ATP) values were evaluated to determine cleanliness after manual cleaning.

RESULTS

Manual cleaning with novel simethicone cleaning protocol demonstrated a significant decrease in fluid droplets (14.6 ± 29.9 vs 0 ± 0, P < 0.001) and ATP values (157 ± 196 relative light units [RLUs] vs 52 ± 41 RLUs, P = 0.031). HLD with simethicone cleaning protocol, using either enzymatic detergent with effective for cleaning simethicone or cleaning time set in the automatic endoscope reprocessor program for 8 min, demonstrated significant decrease in the number of fluid droplets. Follow-up after the implementation of the simethicone cleaning protocol showed a significant decrease in fluid droplets (37.4 ± 41.0 vs 2.1 ± 5.5, P = 0.003) and ATP values (271 ± 268 RLUs vs 82 ± 136 RLUs, P = 0.021).

CONCLUSIONS

Simethicone cleaning protocol is advantageous for significantly decreasing fluid droplets and ATP values within endoscope working channels. After manual cleaning with the simethicone cleaning protocol, in particular, no retained fluid droplet was observed in patient-ready duodenoscopes.

Efficacy of flexible endoscope drying using novel endoscope test articles that allow direct visualization of the internal channel systems

BACKGROUND

Thorough drying of flexible endoscope channels has been identified as an essential reprocessing step. Yet, instructions are not specific on how to dry endoscopes. There is lack of data supporting efficacy of current drying practices, due to limitations in determining channel dryness.

METHODS

Novel endoscope test articles were used to evaluate the effectiveness of alcohol flush and hanging in an ambient endoscope storage cabinet. Prepared test articles were hung in a storage cabinet for 5 days and visually inspected for residual liquid. The procedure for preoperative inspection of endoscopic systems was performed to determine the procedure's efficacy for removing residual liquid. Then, testing was performed to assess the impact of pressure, residual liquid type and route of air application on time to dry using compressed air.

RESULTS

Alcohol flush followed by hanging in an ambient storage cabinet was not effective for drying endoscope channels, and residual liquid was not completely removed after performing the steps of the preoperative inspection of endoscopic channels. The factors impacting effective compressed air drying were channel dependent. For some channels, alcohol increased the time to dry.

CONCLUSIONS

Endoscope drying is complex; borescope evaluation does not ensure a dry device.

Recent Advances in Endoscope Disinfection: Where Do We Stand in the COVID era?

Over 16 million cases worldwide, severe acute respiratory syndrome coronavirus 2 has profoundly affected healthcare as we know it. Given reports of gastrointestinal involvement and viral shedding in the stool, it is unsurprising there are concerns that endoscopic equipment may be a potential vector of viral transmission. Here, we provide an overview of existing practices for endoscope reprocessing, recent developments in the field, and challenges in the COVID-19 environment. Current multi-society guidelines do not advise any change to endoscope disinfection protocols but emphasize strict adherence to recommended practices. However, endoscopy reprocessing staff may benefit from supplemental personal protective equipment measures, especially in high risk situations. Because thorough endoscope reprocessing is highly operator dependent, adequate training of personnel is critical for proper manual cleaning and disinfection of endoscopes that have potential to harbor virus. Bacterial contamination of duodenoscopes has caused outbreaks of infection from multidrug-resistant organisms, highlighting vulnerable areas. The emphasis of current studies is on optimization of disinfection and drying, minimization of simethicone use, and on quality control of endoscope reprocessing with sampling and microbiological culturing. Recent advances include novel approaches to endoscope sterilization, infection barrier methods, and design of partially or fully disposable duodenoscopes. Overall, the available data indicate that, when correctly executed, current reprocessing practices are sufficient in preventing SARS-COV-2 transmission.

The Effectiveness of Drying on Residual Droplets, Microorganisms, and Biofilms in Gastrointestinal Endoscope Reprocessing: A Systematic Review

BACKGROUND

Despite endoscope reprocessing, residual droplets remain in gastrointestinal endoscope working channels. Inadequate drying of gastrointestinal endoscope working channels may promote microbial reproduction and biofilm formation, increasing the risk of infection in patients. This review was designed to provide the current status of gastrointestinal endoscope drying, emphasize the importance of gastrointestinal endoscope drying, and evaluate the effectiveness of different drying methods of gastrointestinal endoscope in reducing residual droplets and microbial growth risk.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting checklist. The PubMed, Web of Science, Medline, EMBASE, EBSCO, CNKI, CQVIP, and Wanfang Data databases were searched from 2010 to 2020 to identify eligible articles focused on methods of gastrointestinal endoscope drying and the status of endoscope drying. The following key points were analyzed: type of intervention, amount of residual droplets, major microbial types, and effectiveness of biofilm intervention. JBI quality assessment tool was used to determine bias risk for inclusion in the article.

RESULTS

This review included twelve articles. Two of the articles reported lack of drying of gastrointestinal endoscopes while the other ten reported residual droplets, microbial growth, and biofilm formation after different methods of drying. Four articles reported 0 to 4.55 residual droplets; four articles reported that the main microbial types were cocci and bacilli, most commonly Staphylococcus, Escherichia coli, Bacillus maltophilia, and Pseudomonas aeruginosa; and two reported that drying could effectively reduce biofilm regeneration. The type of intervention is as follows: automatic endoscopy reprocessor (AER), manual compressed air drying, and the Dri-Scope Aid for automatic drying and drying cabinet.

CONCLUSIONS

While endoscope reprocessing may not always be effective, an automatic endoscope reprocessor plus the Dri-Scope Aid with automatic drying over 10 min or storage in a drying cabinet for 72 h may be preferred.

Duodenoscope-associated infection prevention: A call for evidence-based decision making

Background  Recent outbreaks of duodenoscope-associated multidrug-resistant organisms (MDROs) have brought attention to the infection risk from procedures performed with duodenoscopes. Prior to these MDRO outbreaks, procedures with duodenoscopes were considered safe and low risk for exogenous infection transmission, provided they were performed in strict accordance with manufacturer instructions for use and multisociety reprocessing guidelines. The attention and efforts of the scientific community, regulatory agencies, and the device industry have deepened our understanding of factors responsible for suboptimal outcomes. These include instrument design, reprocessing practices, and surveillance strategies for detecting patient and instrument colonization. Various investigations have made it clear that current reprocessing methods fail to consistently deliver a pathogen-free instrument. The magnitude of infection transmission has been underreported due to several factors. These include the types of organisms responsible for infection, clinical signs presenting in sites distant from ERCP inoculation, and long latency from the time of acquisition to infection. Healthcare providers remain hampered by the ill-defined infectious risk innate to the current instrument design, contradictory information and guidance, and limited evidence-based interventions or reprocessing modifications that reduce risk. Therefore, the objectives of this narrative review included identifying outbreaks described in the peer-reviewed literature and comparing the findings with infections reported elsewhere. Search strategies included accessing peer-reviewed articles, governmental databases, abstracts for scientific conferences, and media reports describing outbreaks. This review summarizes current knowledge, highlights gaps in traditional sources of evidence, and explores opportunities to improve our understanding of actual risk and evidence-based approaches to mitigate risk.

Novel Algorithms for Reprocessing, Drying and Storing Endoscopes

After outbreaks of duodenoscope-transmitted infection with multidrug-resistant organisms, it has become clear that institutions must optimize their endoscope reprocessing programs. Standard endoscope reprocessing practices may not represent the ideal approach for preventing transmission of infection related to endoscopy. We discuss multiple approaches to enhance and optimize reprocessing, drying, and storage of standard duodenoscopes. The optimal enhanced duodenoscope reprocessing modality remains to be determined. Acknowledging the challenges and limitations in effectively reprocessing duodenoscopes, the FDA issued a safety communiqué recommending transitioning to either single use disposable duodenoscopes or duodenoscopes with innovative designs that allow more effective reprocessing.

Methods for Endoscope Reprocessing

Over the past 2 decades, in hospital centers worldwide, there have been numerous outbreaks of multidrug-resistant organisms that have since been attributed to endoscopic transmission of the infections between patients, primarily from duodenoscopes. These outbreaks have focused the attention of endoscope manufacturers, professional societies, and regulatory agencies on improving the reprocessing of these devices. The key steps in this process are point-of-use precleaning, leak testing, manual cleaning, high-level disinfection, and finally drying and storage. The promise of these initial efforts suggest that the aim of minimizing and ultimately eliminating events of endoscope-/duodenoscope-associated transmission of infectious organisms between patients can be achieved.

Quality Systems Approach for Endoscope Reprocessing: You Don't Know What You Don't Know!

Several factors affect the efficacy of endoscope reprocessing, including human factors, inadequate cleaning, simethicone residuals, moisture in channels during storage, and biofilm or buildup biofilm formation. These factors all contribute to contamination of patient-ready endoscopes that may contribute to transmission of microorganisms resulting in infection and/or colonization. This article reviews monitoring as part of a quality management system that includes manual cleaning, dry storage, and culture to detect endoscope contamination. The published data for rapid tests that detect organic residuals and adenosine triphosphate to monitor manual cleaning are reviewed.

SpyGlass application for duodenoscope working channel inspection: Impact on the microbiological surveillance

BACKGROUND

Patient-ready duodenoscopes were designed with an assumed contamination rate of less than 0.4%; however, it has been reported that 5.4% of clinically used duodenoscopes remain contaminated with viable high-concern organisms despite following the manufacturer’s instructions. Visual inspection of working channels has been proposed as a quality control measure for endoscope reprocessing. There are few studies related to this issue.

AIM

To investigate the types, severity rate, and locations of abnormal visual inspection findings inside patient-ready duodenoscopes and their microbiological significance.

METHODS

Visual inspections of channels were performed in 19 patient-ready duodenoscopes using the SpyGlass visualization system in two endoscopy units of tertiary care teaching hospitals (Tri-Service General Hospital and National Taiwan University Hospital) in Taiwan. Inspections were recorded and reviewed to evaluate the presence of channel scratches, buckling, stains, debris, and fluids. These findings were used to analyze the relevance of microbiological surveillance.

RESULTS

Seventy-two abnormal visual inspection findings in the 19 duodenoscopes were found, including scratches (n = 10, 52.6%), buckling (n = 15, 78.9%), stains (n = 14, 73.7%), debris (n = 14, 73.7%), and fluids (n = 6, 31.6%). Duodenoscopes > 12 mo old had a significantly higher number of abnormal visual inspection findings than those ≤ 12 mo old (46 findings vs 26 findings, P < 0.001). Multivariable regression analyses demonstrated that the bending section had a significantly higher risk of being scratched, buckled, and stained, and accumulating debris than the insertion tube. Debris and fluids showed a significant positive correlation with microbiological contamination (P < 0.05). There was no significant positive Spearman’s correlation coefficient between negative bacterial cultures and debris, between that and fluids, and the concomitance of debris and fluids. This result demonstrated that the presence of fluid and debris was associated with positive cultures, but not negative cultures. Further multivariate analysis demonstrated that fluids, but not debris, is an independent factor for bacterial culture positivity.

CONCLUSION

In patient-ready duodenoscopes, scratches, buckling, stains, debris, and fluids inside the working channel are common, which increase the microbiological contamination susceptibility. The SpyGlass visualization system may be recommended to identify suboptimal reprocessing.

Challenges in achieving effective high-level disinfection in endoscope reprocessing

Endoscope reprocessing is often ineffective, and microbes frequently remain on endoscopes after the use of high-level disinfectants (HLDs). Several factors impact reprocessing effectiveness, including non-adherence to guidelines, use of damaged endoscopes, use of insoluble products during endoscopy, insufficient cleaning, contaminated rinse water, and inadequate drying before storage. Our team suspected that issues with HLD chemistries and monitoring could also contribute to reprocessing failures. We conducted a mixed-methods analysis of published literature, our interviews with frontline personnel, and evidence from our previous studies. The evidence showed that reusable HLDs commonly failed tests for minimum effective concentration (MEC) before their maximum usage periods. MEC tests also detected failures associated with single-use HLDs that did not fully deploy. These failures were due to product issues, process complexities, and personnel non-adherence with guidelines and manufacturer instructions. HLDs will likely continue to be used for the foreseeable future. More research is needed to assess real-world practice patterns related to the high-level disinfection step and MEC testing and to establish more realistic usage periods for reusable HLD chemistries. Manufacturers and researchers should evaluate the ability of technological solutions and engineered safeguards to overcome human error. Recognition of the need for quality improvement is growing, and infection preventionists should take action to build on this momentum and collaborate with manufacturers, endoscopists, and reprocessing personnel to improve the effectiveness of high-level disinfection.

Impact of wet storage and other factors on biofilm formation and contamination of patient-ready endoscopes: a narrative review

The 2019 U.S. Food and Drug Administration report indicates that the clinical studies undertaken by the 3 main GI endoscope manufacturers demonstrate 5.4% of patient-ready duodenoscopes remain culture positive for high-concern organisms. The root causes of this persistent contamination are poorly understood. The objectives of this review include summarizing (1) the impact of inadequate manual cleaning and inadequate drying during storage on the formation of build-up biofilm in endoscope channels, (2) the impact of defoaming agents used during patient procedures on drying efficacy, (3) the data showing the importance of build-up biofilm on persistent microbial survival, and (4) the potential impact of implementation of a quality systems approach in GI endoscopy reprocessing.

Duodenoscope-associated infections: a review

Flexible digestive endoscopes are used for the management of various conditions with hundreds of thousands of therapeutic procedures performed worldwide each year. Duodenoscopes are indispensable tools for the delivery of minimally invasive vital care of numerous pancreaticobiliary disorders. Despite the fact that nosocomial infections after endoscopic retrograde cholangiopancreatography (ERCP) have always been among the most frequently cited postprocedural complications, recent emergence of duodenoscope-transmitted multiple drug-resistant bacterial infections has led to intense research and debate yet with no clearly delineated solution. Duodenoscope-transmitted nosocomial infections have become one of the most visible topics in the recent literature. Hundreds of high-impact articles have therefore been published in the last decade. This review article discusses how such infections were seen in the past and what is the current situation in both research and practice and thus tries to solve some of the unanswered questions for the future. With the persistence of nosocomial infections despite strict adherence to both manufacturer-issued reprocessing protocols and international guidelines and regulations, an urgent and proper microbiologically driven common action is needed for controlling such nosocomial worldwide threat.

Endoscope reprocessing: Comparison of drying effectiveness and microbial levels with an automated drying and storage cabinet with forced filtered air and a standard storage cabinet

BACKGROUND

Automated drying may help prevent endoscopically transmitted infections. We aimed to assess the efficacy of an automated drying and storage cabinet compared to a standard storage cabinet in achieving endoscope dryness postreprocessing and in reducing the risk of microbial growth.

METHODS

Drying times of bronchoscopes, colonoscopes, and duodenoscopes using 2 drying platforms (an automated drying and storage cabinet vs a standard storage cabinet) were measured using cobalt chloride paper. Drying assessments occurred at: 30 minutes, 1 hour, 2 hours, 3 hours, and 24 hours. A simple linear regression analysis compared rates of microbial growth after inoculation with Pseudomonas aeruginosa following high-level disinfection at: 0, 3 hours, 12 hours, 24 hours, and 48 hours.

RESULTS

Using the automated drying and storage cabinet, internal channels were dry at 1 hour and external surfaces at 3 hours in all endoscopes. With the standard storage cabinet, there was residual internal fluid at 24 hours, whereas external surfaces were dry at 24 hours. For bronchoscopes, colonoscopes, and duodenoscopes, the standard cabinet allowed for an average rate of colony forming unit growth of 8.1 × 10⁶ per hour, 8.3 × 10⁶ per hour, and 7.0 × 10⁷ per hour, respectively; the automated cabinet resulted in colony forming unit growth at an average rate of -28.4 per hour (P = .02), -38.5 per hour (P = .01), and -200.2 per hour (P = .02), respectively.

CONCLUSIONS

An automated cabinet is advantageous for rapid drying of endoscope surfaces and in reducing the risk of microbial growth postreprocessing.

Gastrointestinal Endoscopy Editorial Board top 10 topics: advances in GI endoscopy in 2018

The American Society for Gastrointestinal Endoscopy's Gastrointestinal Endoscopy Editorial Board reviewed original endoscopy-related articles published during 2018 in Gastrointestinal Endoscopy and 10 other leading medical and gastroenterology journals. Votes from each individual member were tallied to identify a consensus list of 10 topic areas of major advances in GI endoscopy. Individual board members summarized important findings published in these 10 areas of adenoma detection, bariatric endoscopy, EMR/submucosal dissection/full-thickness resection, artificial intelligence, expandable metal stents for palliation of biliary obstruction, pancreatic therapy with lumen-apposing metal stents, endoscope reprocessing, Barrett's esophagus, interventional EUS, and GI bleeding. This document summarizes these "Top 10" endoscopic advances of 2018.

Duodenoscope-Associated Infections beyond the Elevator Channel: Alternative Causes for Difficult Reprocessing

OBJECTIVES

Duodenoscopes have been widely used for both diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures, but recently, numerous outbreaks of multidrug-resistant organisms (MDRO) infections have been reported which has led to extensive research for their possible causes. Consequently, the aim of this study is to search for possible duodenoscope surface damages that could provide an alternative and plausible source of infections.

MATERIALS AND METHODS

In order to assess both outer and inner surfaces, a duodenoscope was dismantled and samples were taken from the outer resin polymer and from the air/water, elevator, and working (biopsy) channels that were characterized by FTIR, DSC, TGA, AFM, SEM techniques and the antimicrobial activity were tested.

RESULTS

Alterations were noticed on both the coating and working channel polymers, with external alterations increasing progressively from the proximal sample to the distal sample near the tip of the scope. However, the results showed that the coating surface was still efficient against bacterial adhesion. Changes in surface texture and also morphological changes were shown.

CONCLUSIONS

The study describes the impact of routine procedural use and reprocessing cycles on the duodenoscope, showing that these may possibly make it susceptible to bacterial contamination and MDRO biofilm formation due to difficult reprocessing of the altered surfaces.

An in vitro and clinical dose-finding study of antifoaming effects of simethicone during colonoscopy

Simethicone is an antifoaming agent frequently added to endoscopic rinse solutions but has recently been implicated as a risk factor for transmission of infections due to the formation of simethicone deposits within scope channels. Since the build-up of residue is likely dose-related, the smallest effective dose of simethicone should be used but there are no data available on the effective dose. Thus, we conducted a dose-finding study in an "in vitro bubble model" to determine the appropriate simethicone dose. Six 100-mL test tubes were filled with a 1% (v/v) solution of kitchen detergent (Fairy®, Procter & Gamble, London, England) in water for irrigation (Baxter®, Sydney, Australia). One test tube served as the control, while different doses of simethicone (Infacol®, Nice Pak, Melbourne, Australia) were added to the other five tubes (0.02, 0.2, 2.0, 20, and 200 mg/100 mL). Oxygen was streamed for 30 s into the test tubes at a rate of 2 L/min. After 10 s, photographs were taken and the visible bubbles were semi-quantitatively rated by independent assessors blinded to the dosing of simethicone. Simethicone at doses of 2 mg/100 mL had no appreciable antifoaming effect, whereas concentrations ≥ 20 mg/100 mL were sufficient to suppress bubble formation. This is substantially lower compared with frequently used doses of up to 200 mg/100 mL. Subsequently, we tested the lower simethicone dose with previously used higher doses, in 1475 and 1340 patients, respectively. We found it to have no impact on polyp detection with a rate of 56.7% (54.2-59.3% [95% CI]) at the lower dose and 56.5% (53.8-59.1% [95% CI]) at the higher dose.

Widespread clinical use of simethicone, insoluble lubricants, and tissue glue during endoscopy: A call to action for infection preventionists

BACKGROUND

Current methods for reprocessing flexible endoscopes do not consistently eliminate organic soil. The off-label use of simethicone as a defoaming agent may contribute to reprocessing failures, and endoscope manufacturers have cautioned against its use.

METHODS

We sought evidence of simethicone use by interviewing hospital personnel, conducting audits, inspecting endoscopes, and conducting tests.

RESULTS

Researchers examined 69 fully reprocessed endoscopes in 4 hospitals. Microbial cultures were positive for ≥50% of endoscopes. Researchers observed cloudy, shimmery fluid resembling simethicone inside channels and under a duodenoscope elevator mechanism. Crystallized white fragments were observed protruding from a gastroscope water jet outlet. Oily, sticky residue was found on endoscopes, and a 3-dimensional mass was found inside an endoscopic ultrasound endoscope. Hospital personnel reported the use of simethicone, cooking oil and silicone sprays, and tissue glue during endoscopy.

DISCUSSION

The off-label use of defoaming agents, lubricants, and tissue glue is common and many endoscopists consider these products essential. Our findings suggest these substances are not removed during reprocessing and may impact reprocessing effectiveness.

CONCLUSIONS

Infection preventionists should determine whether these products are used in their institutions and evaluate methods for removing them. New policies may be needed to support procedural success and effective endoscope reprocessing.