Biofilm accumulation in new flexible gastroscope channels in clinical use

Assess the accumulation of protein and biofilm on the inner surfaces of new flexible gastroscope (FG) channels after 30 and 60 days of patient use and full reprocessing.

Clinical use study of biofilm accumulation in FG channels.

Endoscopy service of a public hospital.

First, we tested an FG in clinical use before the implementation of a revised reprocessing protocol (phase 1 baseline; n = 1). After replacement of the channels by new ones and the implementation of the protocol, 3 FGs were tested after 30 days of clinical use (phase 2; n = 3) and 3 FGs were tested after 60 days of clinical use (phase 3; n = 3), and the same FGs were tested in phase 2 and 3. Their biopsy, air, water, and air/water junction channels were removed and subjected to protein testing (n = 21), bacteriological culture (n = 21), and scanning electron microscopy (SEM) (n = 28). Air-water junction channels fragments were subjected to SEM only.

For the FGs, the average number of uses and reprocessing cycles was 60 times. Extensive biofilm was detected in air, water, and air-water junction channels (n = 18 of 28). All channels (28 of 28) showed residual matter, and structural damage was identified in most of them (20 of 28). Residual protein was detected in the air and water channels of all FG evaluated (phases 1-3), except for 1 air channel from phase 2. Bacteria were recovered from 8 of 21 channels, most air or water channels.

The short time before damage and biofilm accumulation in the channels was evident and suggests that improving the endoscope design is necessary. Better reprocessing methods and channel maintenance are needed.