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

Abstract

Background and aims: Outbreaks of transmission of infection related to endoscopy despite reported adherence to reprocessing guidelines warrant scrutiny of all potential contributing factors. Recent reports from ambulatory surgery centers indicated widespread significant occult damage within endoscope working channels, raising concerns regarding the potential detrimental impact of this damage on the adequacy of endoscope reprocessing.

Methods: We inspected working channels of all 68 endoscopes at our academic institution using a novel flexible inspection endoscope. Inspections were recorded and videos reviewed by 3 investigators to evaluate and rate channel damage and/or debris. Working channel rinsates were obtained from all endoscopes, and adenosine triphosphate (ATP) bioluminescence was measured.

Results: Overall endoscope working channel damage was rated as minimal and/or mild and was consistent with expected wear and tear (median 1.59 on our 5-point scale). Our predominant findings included superficial scratches (98.5%) and scratches with adherent peel (76.5%). No channel perforations, stains, or burns were detected. The extent of damage was not predicted by endoscope age. Minor punctate debris was common, and a few small drops of fluid were noted in 42.6% of endoscopes after reprocessing and drying. The presence of residual fluid predicted higher ATP bioluminescence values. The presence of visualized working channel damage or debris was not associated with elevated ATP bioluminescence values.

Conclusion: The flexible inspection endoscope enables high-resolution imaging of endoscope working channels and offers endoscopy units an additional modality for endoscope surveillance, potentially complementing bacterial cultures and ATP values. Our study, conducted in a busy academic endoscopy unit, indicated predominately mild damage to endoscope working channels, which did not correlate with elevated ATP values.

Figure 1

Schematic depicting the full spectrum of working channel damage from mild to severe: superficial scratches and scratches with adherent peel are almost ubiquitous and consistent with normal “wear and tear.” The significance of deeper scratches and burns is uncertain and these findings should trigger discussion with the manufacturer. Channel buckling may compromise the channel lumen, may impair the ability to advance accessory devices and may impair manual cleaning; channel repair is indicated. Perforations and related stains usually fail leak testing; channel repair is indicated.

Figure 2

Images depicting working channel damage and residue visualized in endoscopes, including (A) superficial scratches at the inlet region (left) and along the endoscope shaft (right), (B) scratches with adherent peel, perpendicular to circular rings of the endoscope bending segment (left) and along the endoscope shaft (right) (C) channel buckling of the endoscope shaft, (D) drops of residual fluid and (E) white punctate (left) and black linear (right) residual debris.

Figure 2

Images depicting working channel damage and residue visualized in endoscopes, including (A) superficial scratches at the inlet region (left) and along the endoscope shaft (right), (B) scratches with adherent peel, perpendicular to circular rings of the endoscope bending segment (left) and along the endoscope shaft (right) (C) channel buckling of the endoscope shaft, (D) drops of residual fluid and (E) white punctate (left) and black linear (right) residual debris.

Figure 2

Images depicting working channel damage and residue visualized in endoscopes, including (A) superficial scratches at the inlet region (left) and along the endoscope shaft (right), (B) scratches with adherent peel, perpendicular to circular rings of the endoscope bending segment (left) and along the endoscope shaft (right) (C) channel buckling of the endoscope shaft, (D) drops of residual fluid and (E) white punctate (left) and black linear (right) residual debris.

Figure 2

Images depicting working channel damage and residue visualized in endoscopes, including (A) superficial scratches at the inlet region (left) and along the endoscope shaft (right), (B) scratches with adherent peel, perpendicular to circular rings of the endoscope bending segment (left) and along the endoscope shaft (right) (C) channel buckling of the endoscope shaft, (D) drops of residual fluid and (E) white punctate (left) and black linear (right) residual debris.

Figure 2

Images depicting working channel damage and residue visualized in endoscopes, including (A) superficial scratches at the inlet region (left) and along the endoscope shaft (right), (B) scratches with adherent peel, perpendicular to circular rings of the endoscope bending segment (left) and along the endoscope shaft (right) (C) channel buckling of the endoscope shaft, (D) drops of residual fluid and (E) white punctate (left) and black linear (right) residual debris.

Figure 3

Graphical boxplot representation of investigator ratings for scratch abundance and characteristics, scratches with adherent peel and residual fluid/debris. Boxes represent interquartile range. Horizontal lines within boxes represent median rating. Whiskers represent the lowest or highest data point still within a 1.5-multiple of the interquartile range. Dots represent outliers.