Borescope inspection of endoscope working channels: Why and how?

Whole-genome sequencing establishes persistence of biofilm-associated Pseudomonas aeruginosa detected from microbiological surveillance of gastrointestinal endoscopes

BACKGROUND

An increased incidence of P. aeruginosa in microbiological surveillance (MS) cultures from gastrointestinal endoscopes was detected between March 2020 to March 2023 in Tan Tock Seng Hospital Singapore. The aim of this report is to describe the use of whole-genome sequencing (WGS) in this investigation.

METHODS

WGS was performed for all P. aeruginosa isolates with pairwise comparison of isolates to assess for genomic linkage. Comprehensive review of reprocessing practices and environmental sampling was performed.

FINDINGS

Twenty-two P. aeruginosa isolates were detected from endoscopic MS cultures. Fifteen (68%) isolates were available for WGS. Eighteen pairwise comparisons of isolates were made, of which 10 were found to be genomically linked. One endoscope had P. aeruginosa repeatedly cultured from subsequent MS that were genomically linked and persistent despite repeat endoscopic reprocessing, establishing the persistence of biofilm that could not be eradicated with routine reprocessing. All P. aeruginosa isolates cultured from other different endoscopes were genetically distinct. Investigation into reprocessing practices revealed the use of air/water valves connected to endoscopes during clinical use. Inspection of these valves revealed the presences of cracks and tears. All other environmental samples were negative.

CONCLUSIONS

The WGS findings helped to deprioritize common source contamination and supported the hypothesis of biofilm buildup within endoscopes leading to repeatedly positive MS cultures that were genomically linked. This was possibly related to incomplete reprocessing of the damaged air/water valves, resulting in biofilm build up. All faulty valves were changed and subsequently cleaned separately with ultrasonic cleaning followed by sterilization which resolved this incident.

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.

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.

Borescope Examination and Microbial Culture Results of Endoscopes in a Tertiary Care Hospital Led to Changes in Storage Protocols to Improve Patient Safety

BACKGROUND

Flexible endoscopes are highly versatile and useful medical instruments, and their proper reprocessing is critical to patient health and safety. The value of routine visual inspections and surveillance of endoscopes in a tertiary care hospital was assessed by performing borescope examinations and microbial sampling on respiratory, gastro-intestinal (GI), and urological endoscopes.

METHODS

A total of 42 endoscopes were cultured, and 36 endoscopes were examined with a borescope. The flush-brush-flush method was used to culture the endoscopes. Microbiologic sampling water was vortexed prior to being suctioned through a membrane filter device. The membrane was plated on a blood agar plate and incubated at 37°C for 48 hours. A 1.9-meter borescope with a 1.6mm diameter was used to perform borescope examinations in an antegrade and retrograde approach.

RESULTS

Positive microbial cultures were seen in 28% of bronchoscopes, 22% of GI endoscopes, and 30% of urological endoscopes. Only Gram-positive colonies were identified in endoscopes that had microbial growth. Borescope examinations revealed multiple abnormalities and damage including channel shredding, filamentous debris, water retention, discoloration, dents, and red particles.

CONCLUSIONS

Borescope examination and microbial sampling should be used routinely to assure endoscopic safety. Borescope examination enabled us to visualize structural damage, foreign material, and moisture within endoscopes. The structural damages and the particles found in endoscopes resulted in timely repair and discontinuation of this type of distal end protectors in our facility.