Ventilated upper airway endoscopic endonasal procedure mask: Surgical safety in the COVID-19 era

Background: COVID-19 poses a risk to the endoscopic skull base surgeon. Significant efforts to improving safety have beenemployed, including the use of personal protective equipment (PPE), preoperative COVID-19 testing, and recently the useof a modified surgical mask barrier. The objective of our cadaveric study is to reduce the risks of pathogen transmissionwith the use of readily available and innovative equipment as a means of creating a three-dimensional (3D) printed mask inaddition to a trocar system for use during endoscopic skull base surgery. Methods: Our study presents the ventilated upper airway endoscopic procedure mask (VPM), a 3D-printed mask with ananterior aperture fitted with a surgical glove with ports designed to allow for surgical instrumentation and side ports toaccommodate suction ventilation and an endotracheal tube. As an alternative, a modified laparoscopic surgery trocar servedas a port for instruments, and, on the contralateral side, rubber tubing was used over the endoscrub sheath to create anairtight seal. On cadaveric models, various surgical approaches were performed which each device to assess for surgicalmaneuverability including septoplasty, maxillary antrostomy, total ethmoidectomy, frontal sinusotomy, and sphenoidotomy.Surgical freedom (SF) and aerosolization were tested in both modalities. Results: The VPM allowed the unimpeded performance of the above-mentioned surgical approaches, using both two- andfour-handed techniques, with excellent surgical maneuverability and access, while maintaining a continuous facial seal.Debris and smoke were ventilated with a size 8-Frazier tip suction, and ambient gas was additionally suctioned by thenegative-pressure VPM. SF with the VPM was equivalent (1.0 cm2 ) to the SF with no mask. With the presence of a posterior septectomy, the endoscopic endonasal trocar (EET) system was effective for posteriorsurgical procedures, allowing access to critical paramedian structures (clivus, sella, and tuberculum), and afforded asuperior surgical seal, but was limited in terms of visualization and maneuverability during anterior approaches. For thisreason, aerosolization studies were only performed in the posterior nasal cavity with the EET. SF was found to be reducedby 55% (SF = 0.45 cm2 ), and surgery anterior to the sphenoid rostrum was limited when using the trocar system. Aerosolization was reduced using both the VPM and EET. During anterior surgery, the VPM reduced particle spillage by 86%.During posterior surgery, the VPM reduced overall particle spillage by 71%, while the EET reduced spillage by 97%.Conclusion: The VPM mask allows for a sealed surgical barrier during endoscopic skull base surgery and may play a criticalrole in advancing skull base surgery in the COVID-19 era. The EET may be a useful alternative for binarial procedures in theposterior nasal cavity and in instances where 3D printing is not available. Additionally, considering the ongoing pandemic,PPE shortage is a serious concern. The VPM may serve as a renewable alternative with various applications. In the future,our team will be performing studies to validate these preliminary findings.