Upper Endoscopy Is an Aerosol-Generating Procedure

It is unclear whether SARS-CoV-2 can be transmitted through the aerosol route during GI endoscopic procedures. As more hospitals and endoscopy units are resuming prepandemic elective procedure case numbers, it is imperative to determine safe ways to conduct procedures. 

In this animal study, 2 laser light-scattering devices were used to visualize droplets generated when inserting and withdrawing the endoscope through a lamb esophagus. Lamb’s esophagus was used as it has a similar luminal diameter, tissue composition, and distensibility to a human esophagus. Two different types of biopsy valve caps were used (a rubber cap with a preexisting perforation and a complete disposable valve cap without a premade perforation), and the tools examined were biopsy forceps, a hemostatic clip, and a cytology brush. 

During repeated insertion and withdrawal of the endoscope in the lamb esophagus, aerosol particles were generated proportionally with the speed at which the endoscope was inserted or withdrawn. The insertion and withdrawal of instruments through the 2 types of biopsy valve caps generated aerosol with no significant difference between the types of caps. A wet cytology brush produced the most particles when not properly retracted before removal, whereas the hemostatic clip and the biopsy forceps produced similar aerosol quantities.