A erosol-generating procedures pose a potential threat to health care workers, especially during this COVID-19 (coronavirus disease 2019) pandemic. Esophagogastroduodenoscopy (EGD) was assumed to be an aerosol-generating procedure and recommendations, therefore, reflect evidence generated from nongastrointestinal aerosol-generating procedures, such as bronchoscopy. However, there is no scientific evidence to support this claim. This study aims to provide scientific evidence on whether EGD is an aerosol-generating procedure and to examine ways of decreasing the amount of aerosol generated. Methods This study was a prospective observational trial to examine aerosol generation during EGD by applying a quantitative approach (see Supplementary Material for details). All patients undergoing EGD at the endoscopy center of the Prince of Wales Hospital from May 7, 2020 to June 1, 2020 were included. Procedures were performed with the patient in the left lateral position with a mouthguard, using a 9.9-mm flexible video gastrointestinal scope (GIF-H290; Olympus Hong Kong and China Limited, Kowloon, Hong Kong SAR). Measurements were taken using the portable GT-526S Handheld Particle Counter (Met One Instruments, Inc, Grants Pass, OR). The 6-channel particle sizes were programmed at 0.3 mm, 0.5 mm, 0.7 mm, 1 mm, 5 mm, and 10 mm. The particle counter was placed within 10 cm of the mouth of the patient once the patient entered the room and measured for at least 1 minute before the start of the procedure. The measurement was continued during the procedure until after the patient left the endoscopy suite.

Synthesis of available observational studies suggests that SLT following primary hepatic resection is a highly applicable strategy with long-term survival outcomes that are comparable to upfront liver transplantation.