Suction mask device: a simple, inexpensive, and effective method of reducing spread of aerosolized particles during endoscopic endonasal surgery in the era of COVID-19

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  • 1 Departments of Neurosurgery and
  • | 2 Head and Neck Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio;
  • | 3 Department of Neurosurgery, University of Mississippi Medical Center, Jackson, Mississippi; and
  • | 4 Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
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OBJECTIVE

Aerosol-generating procedures, including endoscopic endonasal surgery (EES), are a major risk for physicians during the COVID-19 pandemic. Techniques for reducing aerosolization and risk of transmission of COVID-19 during these procedures would be valuable to the neurosurgical community. The authors aimed to simulate the generation of small-particle aerosols during EES and craniectomy in order to develop methods to reduce the spread of aerosolized particles, and to test the effectiveness of these methods.

METHODS

This study was performed at the Anatomical Laboratory for Visuospatial Innovations in Otolaryngology and Neurosurgery at The Ohio State University. The following two scenarios were used to measure three different particle sizes (0.3, 2.5, and 10 µm) generated: 1) drilling frontotemporal bone, simulating a craniectomy; and 2) drilling sphenoid bone, simulating an endonasal approach. A suction mask device was created with the aim of reducing particle release. The presence of particles was measured without suction, with a single Frazier tip suction in the field, and with the suction mask device in addition to the Frazier suction tip. Particles were measured 12 cm from the craniectomy or endonasal drilling region.

RESULTS

In the absence of any aerosol-reducing devices, the number of particles measured during craniectomy was significantly higher than that generated by endonasal drilling. This was true regardless of the particle size measured (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001). The suction mask device reduced the release of particles of all sizes measured in the craniectomy simulation (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001) and particles of 0.3 µm and 2.5 µm in the single Frazier suction simulation (0.3 µm, p = 0.031; and 2.5 µm, p = 0.026). The suction mask device further reduced the release of particles of all sizes during EES simulation (0.3 µm, p < 0.001; and 2.5 µm, p < 0.001) and particles of 0.3 µm and 2.5 µm in the single Frazier suction simulation (0.3 µm, p = 0.033; and 2.5 µm, p = 0.048). Large particles (10 µm) were not detected during EES.

CONCLUSIONS

The suction mask device is a simple and effective means of reducing aerosol release during EES, and it could potentially be used during mastoidectomies. This could be a valuable tool to reduce the risk of procedure-associated viral transmission during the COVID-19 pandemic.

ABBREVIATIONS

EES = endoscopic endonasal surgery.

OBJECTIVE

Aerosol-generating procedures, including endoscopic endonasal surgery (EES), are a major risk for physicians during the COVID-19 pandemic. Techniques for reducing aerosolization and risk of transmission of COVID-19 during these procedures would be valuable to the neurosurgical community. The authors aimed to simulate the generation of small-particle aerosols during EES and craniectomy in order to develop methods to reduce the spread of aerosolized particles, and to test the effectiveness of these methods.

METHODS

This study was performed at the Anatomical Laboratory for Visuospatial Innovations in Otolaryngology and Neurosurgery at The Ohio State University. The following two scenarios were used to measure three different particle sizes (0.3, 2.5, and 10 µm) generated: 1) drilling frontotemporal bone, simulating a craniectomy; and 2) drilling sphenoid bone, simulating an endonasal approach. A suction mask device was created with the aim of reducing particle release. The presence of particles was measured without suction, with a single Frazier tip suction in the field, and with the suction mask device in addition to the Frazier suction tip. Particles were measured 12 cm from the craniectomy or endonasal drilling region.

RESULTS

In the absence of any aerosol-reducing devices, the number of particles measured during craniectomy was significantly higher than that generated by endonasal drilling. This was true regardless of the particle size measured (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001). The suction mask device reduced the release of particles of all sizes measured in the craniectomy simulation (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001) and particles of 0.3 µm and 2.5 µm in the single Frazier suction simulation (0.3 µm, p = 0.031; and 2.5 µm, p = 0.026). The suction mask device further reduced the release of particles of all sizes during EES simulation (0.3 µm, p < 0.001; and 2.5 µm, p < 0.001) and particles of 0.3 µm and 2.5 µm in the single Frazier suction simulation (0.3 µm, p = 0.033; and 2.5 µm, p = 0.048). Large particles (10 µm) were not detected during EES.

CONCLUSIONS

The suction mask device is a simple and effective means of reducing aerosol release during EES, and it could potentially be used during mastoidectomies. This could be a valuable tool to reduce the risk of procedure-associated viral transmission during the COVID-19 pandemic.

In Brief

Researchers demonstrated in the laboratory that a simple, inexpensive face mask attached to suction could effectively reduce aerosol formation during endoscopic endonasal approaches, which could reduce the surgeon's and staff exposure to COVID-19 and other respiratory viruses.

The COVID-19 pandemic has become a worldwide threat to patients and frontline healthcare professionals. Often, healthcare workers face a lack of personal protective equipment.1 As quarantines end and economies reopen in the United States and other countries, the concern and potential risk of COVID-19 transmission during aerosol-generating procedures increases. Many institutions are proceeding with elective surgery only in the case of negative results on a polymerase chain reaction test for COVID-19; however, the known possibility of false-negative results increases the concern for patient and personnel exposure. There are several reports correlating endoscopic endonasal surgery (EES) with increased release of airborne aerosol-containing virus particles.2,3 There are also data demonstrating the presence of concentrated nasal viral load4,5 and stability of aerosolized virus.6 These findings indicate that EES presents an increased risk for virus transmission, and appropriate measures should be enacted to mitigate this risk.

Drilling via endoscopic endonasal procedures has been confirmed to be the main surgical maneuver associated with aerosol formation in cadaveric studies.3,7 According to these studies, transnasal drilling generates aerosol particles larger than 1 µm. However, the size of a coronavirus particle is approximately 0.125 µm, and this virus may have potential to be carried by particles smaller than 1 µm.3,8,9

Furthermore, a few ideas to prevent aerosol spread in the operating room have been reported, including the creation of 3D masks.10–13 Nevertheless, generating masks by 3D printer would be difficult to replicate in many institutions, particularly in developing countries. Therefore, we believe that surgeons need a reliable, inexpensive, and easily reproducible method of reducing aerosolized particle release.

The main goal of the present study was to evaluate the efficacy of a simple and inexpensive mask suction device in reducing the aerosol-generated particles during EES. A craniectomy model was created to serve as a parameter for comparison with EES. Three different particle sizes (0.3, 2.5, and 10 µm) were generated by drilling in two settings (frontotemporal craniectomy and EES) with and without the presence of the suction mask device.

Methods

Study Design

Two embalmed human cadaveric heads were injected with red silicone through the common carotid artery and prepared for dissection in our Anatomical Laboratory for VisuoSpatial Innovations in Otolaryngology and Neurosurgery (ALT-VISION) at The Ohio State University. All experiments were performed in the laboratory.

Aerosol Measurement

Aerosol measurement was performed with a particle counter (HT9600; Dongguan Xintai Instrument Co. Ltd.) that can count three different sizes (0.3, 2.5, and 10 µm) of particles per liter, room temperature, and humidity. Counting efficiency is 100% ± 10%. The sampling time was 50 seconds. All experiments were performed with the ambient room temperature maintained at 24°C ± 1°C and humidity at 50% ± 2%. The cadaveric head was placed supine, and the angle was fixed with the craniectomy site or nostril facing the particle counter. All measurements were performed in the same condition. The height of the particle counter was placed at the same height of the drilling region or nostril (Fig. 1A). Background measurements were obtained prior to the simulation, and at least 3 minutes elapsed between each procedure to allow for verification and confirmation of the number of particles to return to baseline. The increased number of particles was calculated as the difference between the number of particles before drilling and the number of particles after drilling. After 1 minute had elapsed from the drilling activity, sampling was started. Each simulation (craniectomy or endonasal) was conducted using the following three different methods: without suction; with a single Frazier suction tip; and with the suction mask device, which employs a Frazier suction tip in the field and a suction affixed to the mask. To evaluate the relationship between the number of particles and distance from the drilling region, the number of particles was measured with the particle counter located at 5 different distances from the drilling region (12, 24, 48, 72, and 96 cm) and measured 5 times per distance. To compare particle release in the absence of suction, with a single Frazier tip suction, and with the suction mask, the number of particles was measured 10 times with the particle counter located 12 cm away from the region being drilled.

FIG. 1.
FIG. 1.

A: The cadaveric head in the supine and flexed position, at the same height as the drilling region. B: For endonasal drilling, a vacuum tube was inserted into the inferior hole of the mask, and the intubation tube was inserted into the left hole. Each tube was fixed by the Ioban Antimicrobial Incise Drape, and a mask was placed and fixed on the face. C and D: For craniectomy drilling, most of the preparation is the same as that for endoscopic drilling, except that the intubation tube was not used and placed on the drilling region. Figure is available in color online only.

Frazier Suction and Suction Mask Methods

For the single Frazier suction condition, the tip of a 12-F Frazier suction (ConMed) was positioned 2 cm away from the region being drilled. For the suction mask device, a large HD Houdell adult oxygen mask (Putian Maoyuan Network Technology Co., Ltd.) was connected to suction in addition to the 12-F Frazier tip suction in the surgical field. A 6 × 5–cm opening was created in the mask to allow for passage of instruments, surgical maneuverability, and freedom of movement. Additional suction (again 12-F Frazier) was placed in the surgical field 2 cm away from the region being drilled. The metal plate and oxygen tube connector were removed from the mask to increase flexibility, and a hole for the intubation tube was created on the left side. A 6-mm inner-diameter suction tube (Cardinal Health) was inserted into the inferior hole of the mask, and the intubation tube was inserted into the left hole. Both tubes were fixed in position with Ioban Antimicrobial Incise Drape (3M) (Fig. 1B). The mask was placed and fixed by the Ioban Antimicrobial Incise Drape on the drilling region for the craniectomy simulation and on the usual face position for the endonasal procedure. The vacuum pressure of both suctions was 350 mm Hg.

Craniectomy Drilling Simulation

To simulate drilling during a craniectomy, the frontotemporal bone of a cadaver head was exposed. A high-speed Midas Rex Stylus drill (Medtronic) with a 4.5-mm coarse diamond burr at 70,000 rpm was used with irrigation provided at 10 ml/min in all conditions. Three different conditions were evaluated: 1) without suction, 2) with a single 12-F Frazier suction placed in the surgical field 2 cm from the region being drilled, and 3) with the suction mask device in addition to the 12-F Frazier tip suction in the surgical field, as described above (Fig. 1C and D).

Endonasal Drilling Simulation

To simulate drilling during EES, cotton pledgets soaked in hot saline were placed into the nasal cavity, and the intranasal temperature was adjusted to 37°C ± 1°C. For surgical visualization, a high-definition endoscopic camera was attached to a 4-mm 0° endoscope (Stryker). A high-speed Midas Rex Stylus drill (Medtronic) was used on the sphenoid rostrum with a 4.5-mm coarse diamond burr at 70,000 rpm and irrigated at a rate of 10 ml/min. The three different conditions were evaluated as described above. These were identical to the conditions evaluated for craniectomy, except in endonasal procedures, the mask was placed on the cadaver’s face. The Ioban Antimicrobial Incise Drape was used to cover any potential gap formed between the skin and mask to prevent any air leak.

Surgical Maneuverability

To evaluate surgical maneuverability, the suction mask device was placed over the nose of a navigated cadaveric head, and instruments were inserted endonasally. Free angles were defined as the widest amplitude of movement that could be achieved using a straight dissector, in both the craniocaudal direction and the mediolateral direction. Stereotactic navigation was used to illustrate the anatomical limits imposed by the suction mask device.

Statistical Analysis

Evaluation of the relationship between particle number and distance in the absence of suction is displayed as mean ± standard error (SE). Evaluation of the number of particles during simulation of craniectomy or EES without suction, with a single Frazier suction, or with the suction mask device is expressed as a scatterplot and mean number. Statistical analysis of the increasing particle number was performed using IBM SPSS version 26 (IBM Corp.). The Mann-Whitney U-test was used to examine relationships between two variables. Nonparametric statistical techniques were used due to small sample size with Bonferroni correction for multiple comparisons. The level of statistical significance was set at p < 0.05.

Results

Relationship Between Particle Number and Distance in the Absence of Suction

Particles were collected at 5 different distances (12, 24, 48, 72, and 96 cm) from the craniectomy or endonasal drilling region in the absence of any suction. Five replicates per condition were measured. The number of particles measured was inversely proportional to the distance for all particle sizes measured (0.3, 2.5, and 10 µm) in simulation of both craniectomy and EES (Fig. 2A and B).

FIG. 2.
FIG. 2.

A: The mean ± SE number of each particle size (0.3, 2.5, and 10 µm) in the simulation of open craniectomy. B: The mean ± SE number of each particle size (0.3, 2.5, and 10 µm) in the simulation of endonasal drilling. C: The mean number of particles 12 cm away from the areas of external and endonasal drilling without suction. D: Comparison of the mean number of particles 12 cm away from the external drilling area with the three different methods. E: Comparison of the numbers of particles 12 cm away from the endonasal drilling area with the three different methods. *p < 0.05; **p < 0.01. Figure is available in color online only.

Comparison of Craniectomy and Endonasal Drilling

The number of all particles measured at a distance of 12 cm was significantly higher during simulation of craniectomy than during simulation of EES (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001 [Fig. 2C]).

Craniectomy Drilling Simulation

To evaluate aerosolization during craniectomy simulation, airborne particles were measured at a distance of 12 cm from the region being drilled in the absence of suction, with a single 12-F Frazier suction in the field, and with the suction mask device. Ten replicates were collected for each condition. The number of all particles measured with the suction mask device was significantly lower than the number measured without suction (0.3 µm, p < 0.001; 2.5 µm, p < 0.001; and 10 µm, p < 0.001 [Fig. 2D]). Additionally, the number of particles measured with a single Frazier suction was significantly lower than the number measured without suction (0.3 µm, p = 0.038; 2.5 µm, p = 0.049; and 10 µm, p < 0.001 [Fig. 2D]). Notably, the number of 0.3-µm and 2.5-µm particles with the suction mask device was significantly lower than the number measured with a single Frazier suction in the field (0.3 µm, p = 0.031; and 2.5 µm, p = 0.026 [Fig. 2D]).

Endonasal Drilling Simulation

To evaluate aerosolization during simulation of endonasal surgery, airborne particles were collected 10 times at a distance of 12 cm from the region being drilled. The suction mask device significantly reduced the number of 0.3-µm and 2.5-µm particles compared with no suction (0.3 µm, p < 0.001; and 2.5 µm, p < 0.001 [Fig. 2E]). The number of particles detected with a single Frazier suction was significantly lower than that without suction (0.3 µm, p = 0.033; and 2.5 µm, p = 0.048 [Fig. 2E]). Moreover, the number of 0.3-µm and 2.5-µm particles with the suction mask device was significantly lower than that with a single Frazier suction (0.3 µm, p = 0.033; and 2.5 µm, p = 0.048 [Fig. 2E]). No 10-µm particles were detected during endonasal simulation.

Surgical Maneuverability

We evaluated the extent to which the suction mask would affect surgical maneuverability. While we focused on the EES, the free angles are the same for the craniectomy. The free angle in the craniocaudal direction with the mask was 60.8° and that without the mask was 94.7°. The free angle in the mediolateral direction with mask was 89.4° and that without mask was 173.1° (Fig. 3A and B). To illustrate real-world surgical maneuverability using the suction mask, a navigated cadaveric head was used to demonstrate the limits of surgical freedom. Cranially, the posterior aspect of the frontal sinus may be reached without hindrance from the suction mask device (Fig. 3C and D). Caudally, the suction mask device did not limit maneuverability, and the nasal floor was easily reached (Fig. 3E and F). Ipsilaterally, the suction mask did not limit maneuverability, and the lateral wall of the maxillary sinus was easily reached. Contralaterally, the posterior wall of the maxillary sinus was reached roughly halfway to its most lateral aspect (Fig. 3G and H).

FIG. 3.
FIG. 3.

Photographs and the navigation monitor images showing surgical maneuverability. A: The free angles in the craniocaudal direction with (white line) and without (red dotted line) the mask shown from a lateral perspective. B: The free angles in the mediolateral direction with (white line) and without (red dotted line) the mask shown from a caudal perspective. C and D: The cranial limit is the posterior end of the frontal sinus. E and F: There is no caudal limit. G and H: The lateral limit is a midline of the posterior wall of the maxillary sinus. Figure is available in color online only.

Discussion

During the present COVID-19 pandemic, frontline healthcare professionals have been placed at risk. Virus transmission by asymptomatic carriers and false-negative results associated with current testing methodologies complicate efforts at control. In the operating room, the understanding of which procedures create the highest risk of SARS-CoV-2 transmission and how to mitigate that risk remains unclear.14

Prior data suggested that SARS-CoV-2 may be aerosolized during EES;7 however, the risk of transmission via aerosolized particles versus droplets is not completely understood. A SARS-CoV-2 virus particle has a diameter of roughly 60–140 nm,15 indicating that this virus may have the potential to be carried by airborne aerosolized particles less than 1 µm in diameter.16 Even with the development of vaccines, it is unclear when the pandemic will be controlled.

In this study, we sought to, for the first time, evaluate whether drilling during EES and craniectomy generates airborne particles smaller than 1 µm. We also sought to generate and evaluate a simple and reproducible means of reducing aerosolization during these procedures.

Previous work has simulated generation of aerosolized particles.3,7 Workman et al. reported the possibility that aerosol droplets larger than 20 µm can be found at a distance of 36 cm from the nostril during simulation of EES with a cutting burr.3 However, the fluorescein technique they employed is limited in not identifying particles smaller than 20 µm3. Additional previous work inferred that particles 1–10 µm in diameter may be generated by endonasal drilling.7 This work supports that inference and demonstrates for the first time that particles smaller than 1 µm are generated and spread farther away than seen in previous studies.

It is important to understand whether small aerosolized particles are generated by endonasal drilling and the extent to which they travel from the site of drilling. This study suggests that both EES and craniectomy generate small aerosolized particles and that these particles may travel substantial distances. Notably, simulation of EES generates fewer airborne particles than does simulation of craniectomy. EES did not generate any detectable particles 10 µm in size. These results may stem from the natural anatomical enclosure found within the endonasal space and the possibility that these larger particles are naturally trapped by the nasal mucosa.

Workman et al. reported that the use of suction reduces the aerosol generation with endonasal drilling.7 In the operating room, surgeons using the two-handed technique typically employ distal tip suction while drilling. Our results suggest that the suction mask reduces aerosolization compared with a single Frazier distal tip suction and compared with the absence of suction. Moreover, the suction mask may prove useful when the use of distal tip suction is not practical (e.g., one-handed technique during EES).

Complete isolation of patients via the use of a nasal tent or a drape with vacuum would be ideal for prevention of viral transmission;10,13 however, surgical freedom of movement and surgeon comfort may be limited. Additionally, there is a learning curve to operating under a surgical tent or drape.13 Furthermore, the small drape fenestration would be restrictive for the passage of surgical instruments, insertion of pledgets, or tissue removal.10 The suction mask device reduces generation of airborne particles during procedures with only minor reduction of surgical freedom of movement or surgeon comfort. While we found that standard placement of the suction mask limited access to the frontal sinus and lateral half of the maxillary sinus, the mask may be adjusted to allow access if surgery is focused on either of these areas. However, such adjustment may limit access to the opposite aspect of the field. Overall, the angles normally used by the endoscope are not affected by the presence of the mask.

Helman et al.11 reported reduction of aerosolization using a device comprising a 3D-printed mask and trocar stability sleeve. While this method is effective, some institutions may not have access to 3D printing technologies or trocar stability sleeves. Lack of availability may be compounded in the developing world. The concept of a negative airway pressure respirator is similar to our device.12 However, the working corridor of that method is extremely narrow and would potentially affect the freedom of movement.12 The suction mask device presented here costs less than $5 (US) considering that Ioban is already present in the surgical kit and roughly $15 if Ioban must be purchased separately. This method is simple, effective, inexpensive, and reproducible. Furthermore, the suction mask device does not substantially limit surgical freedom of movement or surgeon comfort. However, compared with an airtight isolated method, the suction mask may not be as effective at reducing airborne particle spread.10,11,13 Further study regarding prevention of spread of aerosolized particles is warranted.

There are several limitations to the present study. As in previous reports,3,7 simulation was performed using cadaveric heads. In this study, the cadaveric nasal cavity was warmed and humidified using cotton pledgets. However, such measures may not accurately represent the environment of the live human nasal cavity and dust generated by drilling of live bone. Additionally, environmental factors within individual operating rooms may vary (e.g., temperature, humidity, and airflow), and this would affect aerosolization and spread of airborne particles. Although more particles were detected during craniectomy drilling than during endonasal drilling, there might not be an indication for using the mask suction device during open craniotomy or craniectomy as the concern with SARS-CoV-2 dissemination is minimal to null during these procedures. However, when bone drilling is performed in contact with sinonasal mucosa, as during mastoidectomies and EES, use of the mask suction device may be beneficial. It will decrease the aerosol generated during the procedure, and consequently, it will diminish the risk of exposure of surgeons and staff to potentially contaminated particles.

Further studies are needed to continue the development of inexpensive, reproducible, and effective means of reducing the spread of aerosolized particles during surgical procedures.

Conclusions

The suction mask device presented here represents a simple, effective, and inexpensive method for reducing the spread of particles aerosolized by EES and craniectomy performed during the COVID-19 pandemic. Additional study to verify and improve this technique is warranted.

Acknowledgments

This study was performed at ALT-VISION at The Ohio State University.

Disclosures

Dr. Prevedello: consultant for Stryker, Medtronic Corp., Codman, and Integra; honoraria from Storz and Leica Microsystems; clinical or research support for the study described from Storz and Integra; royalties from ACE Medical, KLS-Martin, and Mizuho; and ownership in eLum, Soliton, and Three Rivers.

Author Contributions

Conception and design: Hara, Zachariah. Acquisition of data: Hara, Li, Martinez-Perez. Analysis and interpretation of data: Prevedello, Hara, Zachariah. Drafting the article: Prevedello, Hara, Zachariah. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Prevedello. Statistical analysis: Hara. Administrative/technical/material support: Prevedello. Study supervision: Prevedello.

References

  • 1

    O'Sullivan ED. PPE guidance for covid-19: be honest about resource shortages. BMJ. 2020;369:m1507.

  • 2

    Patel ZM, Fernandez-Miranda J, Hwang PH, et al. Letter. Precautions for endoscopic transnasal skull base surgery during the COVID-19 pandemic. Neurosurgery. 2020;87(1):E66E67.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3

    Workman AD, Welling DB, 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;10(7):798805.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4

    Bhat TA, Kalathil SG, Bogner PN, et al. An animal model of inhaled vitamin E acetate and EVALI-like lung injury. N Engl J Med. 2020;382(12):11751177.

  • 5

    Peretto G, Sala S, Caforio ALP. Acute myocardial injury, MINOCA, or myocarditis? Improving characterization of coronavirus-associated myocardial involvement. Eur Heart J. 2020;41(22):21242125.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6

    Taylor D, Lindsay AC, Halcox JP. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med. 2020;382:15641567.

  • 7

    Workman AD, Jafari A, Welling DB, et al. Airborne aerosol generation during endonasal procedures in the era of COVID-19: risks and recommendations. Otolaryngol Head Neck Surg. 2020;163(3):465470.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8

    Kashima HK, Kessis T, Mounts P, Shah K. Polymerase chain reaction identification of human papillomavirus DNA in CO2 laser plume from recurrent respiratory papillomatosis. Otolaryngol Head Neck Surg. 1991;104(2):191195.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9

    Kwak HD, Kim SH, Seo YS, Song KJ. Detecting hepatitis B virus in surgical smoke emitted during laparoscopic surgery. Occup Environ Med. 2016;73(12):857863.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    David AP, Jiam NT, Reither JM, et al. Endoscopic skull base and transoral surgery during COVID-19 pandemic: minimizing droplet spread with negative-pressure otolaryngology viral isolation drape. Head Neck. 2020;42(7):15771582.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11

    Helman SN, Soriano RM, Tomov ML, et al. Ventilated upper airway endoscopic endonasal procedure mask: surgical safety in the COVID-19 era. Oper Neurosurg (Hagerstown). 2020;19(3):271280.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12

    Khoury T, Lavergne P, Chitguppi C, et al. Aerosolized particle reduction: a novel cadaveric model and a negative airway pressure respirator (NAPR) system to protect health care workers from COVID-19. Otolaryngol Head Neck Surg. 2020;163(1):151155.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13

    Maharaj SH. The nasal tent: an adjuvant for performing endoscopic endonasal surgery in the Covid era and beyond. Eur Arch Otorhinolaryngol. 2020;277(10):29292931.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14

    Gao Z, Xu Y, Sun C, et al. A systematic review of asymptomatic infections with COVID-19. J Microbiol Immunol Infect. 2021;54(1):1216.

  • 15

    Zhu N, Zhang D, Wang W, et al. A novel coronavirus from patients with pneumonia in China, 2019. N Engl J Med. 2020;382:727733.

  • 16

    Fehr AR, Perlman S. Coronaviruses: an overview of their replication and pathogenesis. Methods Mol Biol. 2015;1282:123.

Illustration from Fan et al. (pp 1298–1309). Copyright Jun Fan. Published with permission.

  • View in gallery

    A: The cadaveric head in the supine and flexed position, at the same height as the drilling region. B: For endonasal drilling, a vacuum tube was inserted into the inferior hole of the mask, and the intubation tube was inserted into the left hole. Each tube was fixed by the Ioban Antimicrobial Incise Drape, and a mask was placed and fixed on the face. C and D: For craniectomy drilling, most of the preparation is the same as that for endoscopic drilling, except that the intubation tube was not used and placed on the drilling region. Figure is available in color online only.

  • View in gallery

    A: The mean ± SE number of each particle size (0.3, 2.5, and 10 µm) in the simulation of open craniectomy. B: The mean ± SE number of each particle size (0.3, 2.5, and 10 µm) in the simulation of endonasal drilling. C: The mean number of particles 12 cm away from the areas of external and endonasal drilling without suction. D: Comparison of the mean number of particles 12 cm away from the external drilling area with the three different methods. E: Comparison of the numbers of particles 12 cm away from the endonasal drilling area with the three different methods. *p < 0.05; **p < 0.01. Figure is available in color online only.

  • View in gallery

    Photographs and the navigation monitor images showing surgical maneuverability. A: The free angles in the craniocaudal direction with (white line) and without (red dotted line) the mask shown from a lateral perspective. B: The free angles in the mediolateral direction with (white line) and without (red dotted line) the mask shown from a caudal perspective. C and D: The cranial limit is the posterior end of the frontal sinus. E and F: There is no caudal limit. G and H: The lateral limit is a midline of the posterior wall of the maxillary sinus. Figure is available in color online only.

  • 1

    O'Sullivan ED. PPE guidance for covid-19: be honest about resource shortages. BMJ. 2020;369:m1507.

  • 2

    Patel ZM, Fernandez-Miranda J, Hwang PH, et al. Letter. Precautions for endoscopic transnasal skull base surgery during the COVID-19 pandemic. Neurosurgery. 2020;87(1):E66E67.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3

    Workman AD, Welling DB, 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;10(7):798805.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4

    Bhat TA, Kalathil SG, Bogner PN, et al. An animal model of inhaled vitamin E acetate and EVALI-like lung injury. N Engl J Med. 2020;382(12):11751177.

  • 5

    Peretto G, Sala S, Caforio ALP. Acute myocardial injury, MINOCA, or myocarditis? Improving characterization of coronavirus-associated myocardial involvement. Eur Heart J. 2020;41(22):21242125.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6

    Taylor D, Lindsay AC, Halcox JP. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med. 2020;382:15641567.

  • 7

    Workman AD, Jafari A, Welling DB, et al. Airborne aerosol generation during endonasal procedures in the era of COVID-19: risks and recommendations. Otolaryngol Head Neck Surg. 2020;163(3):465470.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8

    Kashima HK, Kessis T, Mounts P, Shah K. Polymerase chain reaction identification of human papillomavirus DNA in CO2 laser plume from recurrent respiratory papillomatosis. Otolaryngol Head Neck Surg. 1991;104(2):191195.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9

    Kwak HD, Kim SH, Seo YS, Song KJ. Detecting hepatitis B virus in surgical smoke emitted during laparoscopic surgery. Occup Environ Med. 2016;73(12):857863.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    David AP, Jiam NT, Reither JM, et al. Endoscopic skull base and transoral surgery during COVID-19 pandemic: minimizing droplet spread with negative-pressure otolaryngology viral isolation drape. Head Neck. 2020;42(7):15771582.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11

    Helman SN, Soriano RM, Tomov ML, et al. Ventilated upper airway endoscopic endonasal procedure mask: surgical safety in the COVID-19 era. Oper Neurosurg (Hagerstown). 2020;19(3):271280.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12

    Khoury T, Lavergne P, Chitguppi C, et al. Aerosolized particle reduction: a novel cadaveric model and a negative airway pressure respirator (NAPR) system to protect health care workers from COVID-19. Otolaryngol Head Neck Surg. 2020;163(1):151155.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13

    Maharaj SH. The nasal tent: an adjuvant for performing endoscopic endonasal surgery in the Covid era and beyond. Eur Arch Otorhinolaryngol. 2020;277(10):29292931.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14

    Gao Z, Xu Y, Sun C, et al. A systematic review of asymptomatic infections with COVID-19. J Microbiol Immunol Infect. 2021;54(1):1216.

  • 15

    Zhu N, Zhang D, Wang W, et al. A novel coronavirus from patients with pneumonia in China, 2019. N Engl J Med. 2020;382:727733.

  • 16

    Fehr AR, Perlman S. Coronaviruses: an overview of their replication and pathogenesis. Methods Mol Biol. 2015;1282:123.

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