Endonasal instrumentation and aerosolization risk in the era of COVID-19: simulation, literature review, and proposed mitigation strategies.

Background: International experience with coronavirus 2019 (COVID-19) suggests it poses a significant risk of infectious transmission to skull base surgeons, due to high nasal viral titers and the unknown potential for aerosol generation during endonasal instrumentation. The purpose of this study was to simulate aerosolization events over a range of endoscopic procedures to obtain an evidence-based aerosol risk assessment.

Methods: Aerosolization was simulated in a cadaver using fluorescein solution (0.2 mg per 10 mL) and quantified using a blue-light filter and digital image processing. Outpatient sneezing during endoscopy was simulated using an intranasal atomizer in the presence or absence of intact and modified surgical mask barriers. Surgical aerosolization was simulated during nonpowered instrumentation, suction microdebrider, and high-speed drilling after nasal fluorescein application.

Results: Among the outpatient conditions, a simulated sneeze event generated maximal aerosol distribution at 30 cm, extending to 66 cm. Both an intact surgical mask and a modified VENT mask (which enables endoscopy) eliminated all detectable aerosol spread. Among the surgical conditions, cold instrumentation and microdebrider use did not generate detectable aerosols. Conversely, use of a high-speed drill produced significant aerosol contamination in all conditions tested.

Conclusion: We confirm that aerosolization presents a risk to the endonasal skull base surgeon. In the outpatient setting, use of a barrier significantly reduces aerosol spread. Cold surgical instrumentation and microdebrider use pose significantly less aerosolization risk than a high-speed drill. Procedures requiring drill use should carry a special designation as an "aerosol-generating surgery" to convey this unique risk, and this supports the need for protective personal protective equipment.