Successful realisation of a fully automated endoscope cleaning system

Endoscopes, especially duodenoscopes, may still be contaminated after cleaning and thus have potential for transferral of infective agents from one patient to another. This study aimed to assess whether the manual stages in endoscope cleaning could be replaced with a fully automated cleaning process to give improved cleaning outcomes.

New materials were developed that act in concert to provide high levels of antimicrobial activity. A prototype automated endoscope cleaner was constructed to exploit these new materials and enable a fully automated endoscope cleaning system to be assessed against conventional manual cleaning protocols.

The new materials generated 10⁷- to 10⁸-fold reductions, equivalent to that observed in high-level disinfection, in microbial biofilms grown on endoscope tubing. The materials were active against all the main bacterial strains required by British Standard BS EN 13697:2015+A1:2019 and also the yeast, Candida albicans. A prototype automated endoscope cleaner, designed to use these materials, was built and assessed, in a non-human trial, for the ability to clean two different types of flexible endoscope (endoscopic retrograde cholangiopancreatography scope and gastrointestinal scope) contaminated with a bacterial-based artificial test soil (either Klebsiella pneumoniae or Pseudomonas aeruginosa). For both scope types, the fully automated endoscope cleaning system gave excellent reductions in levels of bacterial loadings (10¹⁰- to 10^8.8-fold) and was found to be generally about 100 times more effective than manual cleaning.

The results indicate that fully automated cleaning of endoscopes is now a realistic possibility, with potential for significant health and cost benefits.