Surgical mask designed for endoscopic procedures to prevent the diffusion of droplets

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2) has become a global pandemic. The human-tohuman transmission of SARS-CoV-2 occurs primarily through droplets, aerosols, and direct contact. Endoscopy is performed at a short physical distance between an endoscopist and patient, which increases the risk of SARS-CoV-2 transmission to the endoscopist through contact with body fluids and exposure to droplets due to vomiting, retching, and coughing during endoscopic procedures (1). Gastrointestinal endoscopic procedures generate aerosols, which mandates the use of appropriate personal protective equipment (PPE) (1,2). To further reduce the risk of viral infection during endoscopy, additional infection protection is needed to assist PPE from not only the side of endoscopists but also the side of patients (3). Various infection prevention devices, such as a reusable plastic cube barrier, have been reported (3); however, we focused on a surgical mask as a simple and inexpensive method (4). Previous studies proposed modified surgical masks with an endoscopic insertion port, which were handmade with an incision for endoscope insertion into commercially available surgical masks (2,4). Although these “handmade” masks may be easily modified, their preparation is burdensome and not sterile. We developed a novel disposal surgical mask with a mask manufacturer that is specifically designed as a droplet prevention device for endoscopic procedures that may be massproduced with uniform quality and easily introduced into endoscopy units. This novel surgical mask has a 10-mm slit in the center for the insertion of an endoscope and two small 6-mm slits for suction on the left and right. The width of the pleats in the center have been widened to easily cut the slits, which allows for cost-effective mass production. Despite its close fit, the narrow slit allows for the easy passage of an endoscope and smooth endoscopic manipulation. Furthermore, the leakage of droplets and aerosols through the slit in the surgical mask is minimized (Fig. 1A-D).