Aerosol Dispersion During Mastoidectomy and Custom Mitigation Strategies for Otologic Surgery in the COVID-19 Era

Otolaryngol Head Neck Surg. 2021 Jan;164(1):67-73. doi: 10.1177/0194599820941835. Epub 2020 Jul 14.

Abstract

Objective: To investigate small-particle aerosolization from mastoidectomy relevant to potential viral transmission and to test source-control mitigation strategies.

Study design: Cadaveric simulation.

Setting: Surgical simulation laboratory.

Methods: An optical particle size spectrometer was used to quantify 1- to 10-µm aerosols 30 cm from mastoid cortex drilling. Two barrier drapes were evaluated: OtoTent1, a drape sheet affixed to the microscope; OtoTent2, a custom-structured drape that enclosed the surgical field with specialized ports.

Results: Mastoid drilling without a barrier drape, with or without an aerosol-scavenging second suction, generated large amounts of 1- to 10-µm particulate. Drilling under OtoTent1 generated a high density of particles when compared with baseline environmental levels (P < .001, U = 107). By contrast, when drilling was conducted under OtoTent2, mean particle density remained at baseline. Adding a second suction inside OtoTent1 or OtoTent2 kept particle density at baseline levels. Significant aerosols were released upon removal of OtoTent1 or OtoTent2 despite a 60-second pause before drape removal after drilling (P < .001, U = 0, n = 10, 12; P < .001, U = 2, n = 12, 12, respectively). However, particle density did not increase above baseline when a second suction and a pause before removal were both employed.

Conclusions: Mastoidectomy without a barrier, even when a second suction was added, generated substantial 1- to 10-µm aerosols. During drilling, large amounts of aerosols above baseline levels were detected with OtoTent1 but not OtoTent2. For both drapes, a second suction was an effective mitigation strategy during drilling. Last, the combination of a second suction and a pause before removal prevented aerosol escape during the removal of either drape.

Keywords: COVID-19; OtoTent; SARS-CoV-2; aerosol; aerosol generating procedure; aerosolization; airborne; barrier drape; health care providers; mastoidectomy; neurotology; otology; personal protective equipment; safety; severe acute respiratory syndrome coronavirus-2; virus transmission.

MeSH terms

  • Aerosols / adverse effects*
  • COVID-19 / epidemiology*
  • Cadaver
  • Comorbidity
  • Disease Transmission, Infectious / prevention & control*
  • Ear Diseases / epidemiology
  • Ear Diseases / surgery*
  • Humans
  • Mastoid / surgery
  • Mastoidectomy / methods*
  • Otologic Surgical Procedures / methods
  • Otologic Surgical Procedures / standards*
  • Personal Protective Equipment*
  • SARS-CoV-2

Substances

  • Aerosols