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.