Droplet and Aerosol Generation With Endonasal Surgery: Methods to Mitigate Risk During the COVID‐19 Pandemic

Abstract

Objective To define the aerosol and droplet risks associated with endonasal drilling and to identify mitigation strategies. Study Design Simulation series with fluorescent 3-dimensional (3D) printed sinonasal models and deidentified cadaveric heads. Settings Dedicated surgical laboratory. Subjects and Methods Cadaveric specimens irrigated with fluorescent tracer and fluorescent 3D-printed models were drilled. A cascade impactor was used to collect aerosols and small droplets of various aerodynamic diameters under 15 µm. Large droplet generation was measured by evaluating the field for fluorescent debris. Aerosol plumes through the nares were generated via nebulizer, and mitigation measures, including suction and SPIWay devices, nasal sheaths, were evaluated regarding reduction of aerosol escape from the nose. Results The drilling of cadaveric specimens without flexible suction generated aerosols ≤3.30 µm, and drilling of 3D sinonasal models consistently produced aerosols ≤14.1 µm. Mitigation with SPIWay or diameter-restricted SPIWay produced same results. There was minimal field contamination in the cadaveric models, 0% to 2.77% field tarp area, regardless of drill burr type or drilling location; cutting burr drilling without suction in the 3D model yielded the worst contamination field (36.1%), followed by coarse diamond drilling without suction (19.4%). The simple placement of a flexible suction instrument in the nasal cavity or nasopharynx led to complete elimination of all aerosols ≤14.1 µm, as evaluated by a cascade impactor positioned immediately at the nares. Conclusion Given the findings regarding aerosol risk reduction, we strongly recommend that physicians use a suction instrument in the nasal cavity or nasopharynx during endonasal surgery in the COVID-19 era.

Innovations in otorhinolaryngology in the age of COVID‐19: A systematic literature review

“…They found that their negative airway respirator (NAPR), designed by drilling a small hole in the plastic bottom of a standard Ambu mask and inserting a suction tubing, allowed no particles to escape. 52 Dharmaraian et al 53 conducted similar studies in cadaver models to evaluate the efficacy of SPIWay® Endonasal sheaths in mitigating aerosol dispersion caused by endonasal drilling. These endonasal sheaths are typically used to reduce mucosal trauma during endoscopic procedures and to avoid contaminating scope lenses with surgical debris.…”

“…When a flexible suction was inserted in addition to the SPIWays®, no aerosols were detected during drilling. 53 …”

“… David AP, Jiam NT, Reither JM, et al 54 Prototype description and observational study ( n =4 patients) Level 4 (case study) Risk of Bias: Moderate(no control group; dye may not adequately reflect droplet behavior) SPIWay® Endonasal sheaths with flexible suction were used to mitigate aerosol dispersion during endoscopic drilling. Dharmarajan H, Freiser ME, Sim E, et al 53 Preclinical evaluation of prototypes: comparison Level 4 (case-control simulation) Risk of Bias: Moderate(cadaver study and lab setting may not accurately reflect in vivo OR conditions) Study consisted of field contamination survey, simulation of aerosol dynamics, and evaluation of particle generation and spread under various mitigation measures. Suction was found to eliminate all detectable aerosols.…”

Aerosolisation in endonasal endoscopic pituitary surgery

“…Both of these studies found that drilling generated aerosol. Subsequently, Dharmarajan and colleagues utilised a cascade impactor to demonstrate the aerosol produced during endonasal drilling of cadaver and manikin models can be completely mitigated with placement of a suction instrument in the nasal cavity or nasal pharynx [ 15 ].…”

Das erste Jahr der Pandemie mit SARS-CoV-2 – Auswirkungen auf die Hals-Nasen-Ohren-Heilkunde

“…Insbesondere bei der starren oder flexiblen Endoskopie der Nase, des Nasenrachenraums, des Oro‑/Hypopharynx und des Larynx wird von einer Aerosolbildung ausgegangen[ 18 , 38 ]. Rhino‑, Sinus- und Rhinobasischirurgie Durch die Manipulation an den Schleimhäuten, die als am stärksten virustragend identifiziert wurden, kommt es zu einer noch stärkeren Aerosolbildung in der näheren und auch weiteren Umgebung, sodass der komplette Operationsraum als kontaminiert angesehen werden sollte [ 10 , 33 , 48 , 49 ]. Besonders die Verwendung von Bohrern oder Shavern („powered instrumentation“) soll die Aerosolbildung fördern [ 33 ].…”