Introduction
The SARS-CoV-2 / COVID-19 pandemic presents a number of previously unconsidered challenges for otological surgeons. Not least of these is how to perform aerosol generating mastoid surgery whilst minimising the risk of coronavirus transmission to the surgeon and theatre staff.
Mastoid surgery involves the use of high-speed drills within the mastoid air-cell system and as such is considered to be an aerosol generating procedure (AGP). The mastoid air-cells are lined with respiratory mucosa, continuous with the middle ear and nasopharynx via the Eustachian tube. The middle ear has been demonstrated to harbour pathogens including coronavirus1. The plume of potentially virus-containing aerosol generated by the high-speed drill poses a risk to the surgeon and operating theatre staff2,3.
The UK government and specialist healthcare bodies currently recommend the use of personal protective equipment (PPE) for all surgery involving the use of high-speed drills4,5. This includes, as a minimum, fluid-resistant long-sleeved gowns, gloves, filtering facepiece (FFP-3 rated) respirator masks and eye/face protection. Whilst some degree of eye protection is conferred by surgical masks with integrated visors or by polycarbonate safety spectacles, current Public Health England (PHE) guidance specifically recommends the use of a full-face shield or visor for AGPs4.
The challenge specific to the otological surgeon is the need to use an operating microscope when performing mastoidectomy. The full-face shield recommended for AGPs introduces a physical barrier, increasing the distance between the surgeon’s eyes and the operating microscope eyepieces. This may reduce the microscopic view of the surgical field, making surgery more difficult and potentially increasing the risk of surgical error.
In order to quantify this concern, we undertook a study designed to examine the effect of different forms of PPE on the operator-microscope distance and the effect this has on the surgical view obtained by the operator.