2.2 Role of suction
The potential mitigation effects of suction during endonasal surgery were evaluated in five studies.14,15,20,21,24 Two studies considered the role of suction in mitigating spread of droplets. Sharma et al. (2020)14 noted that the introduction of a third hand for concurrent suction completely eliminated detection of fluorescein-soaked droplets following use of both microdebrider and endonasal drill. Leong et al. (2021)15 also noted that suction during microdebrider use eliminated droplet spread, achieved through use of the inbuilt suction alone (without an additional device) provided microdebrider hand-piece settings were set at 2000rpm oscillation, 25mL/min irrigation and 200mmHg suction pressure. The results of Leong et al. (2021)15 differed from those of Sharma et al. (2020)14 in their finding of ongoing droplet spread despite the addition of a second suction device during high-speed drill use. This could be explained by methodological differences however as though the drilling simulations in the Sharma et al. (2020) study were run for a longer duration than those by Leong et al. (2021) (being three minutes rather than one minute of powered instrumentation), the concentration of fluorescent tracer used in their cadaveric work was much lower (1mg/mL of fluorescein versus 40mg/mL).
Workman et al. (2020c)20, Dharmarajan et al. (2021)24 and Sharma et al. (2021a)21examined the role of suction in mitigating the spread of smaller particles ≤10μm in size. Workman et al. (2020c)20noted a reduction in the detection of particles 1-10μm down to baseline levels, with use of a third-hand delivering nasopharyngeal suction, during simulated high-speed drilling of both the sphenoid rostrum and medial maxillary wall for five-minute periods. Dharmarajan et al. (2021)24 also found that in two-minute simulations of drilling of the sphenoid rostrum, detection of particles ≤3.3μm were eliminated through use of an additional third-hand suction device, irrespective of whether it was positioned within the nasopharynx or just inside the nasal cavity. As has been discussed above, the work of Sharma et al. (2021a)21 considered a greater range of particles 0.3-10μm. They also noted the significant impact of adding in concurrent rigid suction with marked reduction in particle detection following simulations of sphenoid drilling, electrocautery and use of the ultrasonic aspirator but, perhaps in keeping with the greater sensitivity of the OPC they utilised, their study did reveal that aerosolisation was ongoing despite the reductions described. Sharma et al. (2021a)21 delved further into the impact of suction, comparing the impact of concurrent endonasal suction with both the construction of a suction ring surrounding the nares and a surgical smoke evacuation system, mounted over the patient’s mouth. They noted the surgical smoke evacuation system to be the most superior device, recommending its use alongside concurrent nasal rigid suction to mitigate risk further.