I thank our respected colleagues Drs Snyderman and Gardner for their comments on our study. 1 In their letter they describe a study in which they performed a 4‐handed skull base surgical approach in 2 cadaver heads irrigated with a fluorescein solution using a 60,000‐rpm coarse diamond bur and 8‐Fr suction. The endpoint of their study was examination of the field and surgeon personal protective equipment (PPE) using a ultraviolet light. They observed no evidence of droplets with some contact contamination and concluded they were unable to replicate our findings.
To provide a comprehensive response, we direct the authors to our follow‐up study by Workman et al. 2 In the study, we repeated the cadaver drilling conditions using 10‐Fr suction, through biting forceps, a suction microdebrider, a suction irrigating 12k drill, 70k 4‐mm diamond, and cutting burs, as well as a cautery device. Our endpoints were airborne aerosol production quantified using an optical particle sizer sensitive to particles <10 µm. This study confirmed the findings of our original study in that, using suction, hand‐actuated instruments, and the microdebrider did not produce detectable particles. However, all drill conditions and cautery produced thousands to tens of thousands of airborne aerosols within only 30 seconds. We did find a definitive benefit to the simultaneous application of suction during drilling, which appears commensurate with the findings reported by the Pittsburgh group.
These results confirm that the application of drills and cautery, procedures common to endonasal skull base approaches, pose a highly significant risk of aerosol production. The methodology described by Snyderman and Gardner differs from our original study both in surgical technique and the use of a much less sensitive and strictly qualitative method of droplet detection. Consequently, their findings cannot be called a lack of replication but rather a companion data set under independent conditions with independent results. On the other hand, our follow‐up study findings suggest that the concomitant application of suction while drilling does confer a benefit that seems consistent with the Pittsburgh findings. 2
Ultimately, I am generally in full agreement with Snyderman and Gardner in their closing thoughts. Although we have identified a series of risk factors germane to the operative team during endonasal surgery, we concur that there are both source control and provider PPE strategies that can be utilized to enable these types of surgery to continue in a safe manner.
Potential conflicts of interest: B.S.B. has consultant relationships with Olympus, Medtronic, Karl Storz, Sinopsys, Baxter, and 3D Matrix, and receives royalties from Thieme. He holds patents for “Treatment of Sinusitis Through Modulation of Cell Membrane Pumps” (nonprovisional USP assigned to the Massacusetts Eye and Ear Infirmary), “Inhibition of Cystatins for the Treatment of Chronic Rhinosinusitis” (nonprovisional USP), and “Methods of Delivery Pharmaceutical Agents” (US 13/561,998). B.S.B. is working with industry to develop source control solutions for endoscopic procedures, which may include an equity position in the future.
References
- 1. Workman AD, Bradley Welling D, Carter BS, et al. Endonasal instrumentation and aerosolization risk in the era of COVID‐19: simulation, literature review, and proposed mitigation strategies. Int Forum Allergy Rhinol. 2020;XX:000‐000. [DOI] [PubMed] [Google Scholar]
- 2. Workman AD, Jafari A, Bradley Welling D, et al. Airborne aerosol generation during endonasal procedures in the era of COVID‐19: risks and recommendations. Otolaryngol Head Neck Surg. 2020;XX:000‐000. [DOI] [PMC free article] [PubMed] [Google Scholar]