Published online Jul 14, 2020. doi: 10.3748/wjg.v26.i26.3767
Peer-review started: February 16, 2020
First decision: May 1, 2020
Revised: May 28, 2020
Accepted: June 23, 2020
Article in press: June 23, 2020
Published online: July 14, 2020
Processing time: 147 Days and 5.2 Hours
The working channels of endoscopes are subjected to wear and tear. Damaged channels allow bacteria to adhere and hide, and the biofilms that form are subsequently difficult to remove. Visual channel inspection has been proposed as a quality control measure for endoscope reprocessing.
Endoscopes with damaged working channels have been considered as sources of microbiological contamination. The FDA recommended returning duodenoscopes to the manufacturer for inspection, servicing, and maintenance at least once a year. Visual inspection may identify certain abnormalities and improve endoscopic quality and care of duodenoscope reprocessing. However, many questions have been raised regarding the visual inspection findings on working channels in real-world situations. Studies related to such situations are too limited to provide sufficient information.
We aimed to investigate the type, severity, location, and clinical significance of visual inspections inside patient-ready duodenoscopes.
Visual inspection of channels was performed in 19 duodenoscopes. Inspections were recorded and reviewed to evaluate for channel damage (scratches, buckling, and stains), debris (dark-colored debris, light-colored debris, and other debris), and fluids (clear fluid and opaque fluid). Visual inspection findings were used to analyze the relevance of microbiological surveillance.
We found 72 abnormal visual inspection findings in the 19 duodenoscopes viewed in our study, 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).
In patient-ready duodenoscopes, scratches, buckling, stains, debris, and fluids inside the working channel are common. Presence of debris and fluids increases the susceptibility to microbiological contamination. The presence of fluids was found to be an independent factor for bacterial culture positivity. Visual channel inspection using the SpyGlass visualization system may be added to the existing visual inspection recommendations to identify suboptimal reprocessing or endoscopes requiring repair or replacement.
Endoscopists should routinely or intermittently visualize the working channel during working hours. Early detection of these abnormal visual inspection findings may allow timely reporting to the manufacturers and promote prompt performance of quality assurance interventions before the channel lumen becomes comprised, which could impair manual cleaning.