Patients admitted to the ICU often require prolonged mechanical ventilation. The European Laryngological Society has issued an important statement, alerting clinicians for an unprecedented increase of laryngo-tracheal stenosis (LTS)¹.

COVID-19 has made safe performance of airway procedures a challenge, for diagnosis as well as treatment. It requires preparedness for prevention and timely management of LTS, with special attention to infection control.

The current strategies to manage the compromized airway include jet ventilation, high flow nasal oxygenation, tracheotomy and ECMO. While the first two options are minimally invasive, aerosols are generated and spread, also ventilation may be less effective in specific patients (e.g. obese). The opposite counts for the latter two options: tracheotomy and ECMO are highly invasive techniques with less aerosol generation and adequate ventilation.

Tritube® is an ultrathin endotracheal tube (OD 4.4mm) with a cuff. It provides a minimally invasive intubation in the compromized airway^2,3, provides a great surgical exposure^2–6, reduces aerosol generation and spread, and enables highly effective ventilation using Evone®^,5-7. As such Tritube and Evone were found key tools in managing the infraglottic difficult airway in the setting of the Coronavirus pandemic.⁸

 Tracheostomy is a highly aerosol generating procedure, exposing health care providers to viral contamination via air droplets⁹. Though it is performed often in patients requiring prolonged mechanical ventilation. In the light of the COVID-19 pandemic, approaches to reduce the risk of virus spreading are urgently needed. While conventional tracheostomy is a highly aerosol generating procedure, introduction of Tritube and FCV ventilation using Evone uniquely allows the placement of a transtracheal cannula in a sealed airway¹⁰. Thereby, virus spread by air droplets is contained, and adequate ventilation of potentially severely hypoxic patients without apneic periods is ensured. The small outer diameter of Tritube additionally provides a good working space for the surgeon.

During upper airway surgery, jet ventilation through a small lumen allows intubation of difficult airways and provides surgical space. Airway patency is required to allow passive backflow of gases, which in turn causes movements of tissue (vocal cords) and secretions/debris, hampering the surgeon’s working conditions and increase contamination risk. To avoid these movements, periods of apnea may be applied. However, during apnea the surgeon has a limited amount of time to perform the required handling, which is considered stressful, and sequential periods of apnea will significantly add to the surgical time. Alternatively, the use of a cuffed micro-laryngeal tube (MLT) with a smaller inner diameter (ID) than conventional tubes (5–6 vs. 7–8 mm) allows passive expiration in most cases and prevents the undesirable movement of anatomical and physiological structures. Moreover, the cuff seals the airway and protects the patient from aspiration. However, the 5 mm ID tubes in particular may cause ventilation issues as the pressure in the lungs cannot be reduced fast enough.

Tritube improves intubation and surgical conditions as compared to MLT-6 (figure)⁵. From a surgeon’s point of view Tritube and Evone have benefits over jet ventilation⁶. Further, Tritube is well tolerated when left in situ after surgery and can therefore be of value to reduce extubation risks^2,3.

Case report: Post-COVID-19 patient tracheal stenosis

A Post-COVID-19 patient presented with severe tracheal stenosis. While the ECMO team was standby Dr Nabil Shallik managed to successfully intubate and ventilate this patient with Tritube and Evone. Tritube provided the surgeons the workspace they needed, with minimized aerosol generation.

 The video demonstrates:

1. Field of interest examination on the airway and guidewire placement under spontaneous ventilation
2. Advancing Tritube over the guidewire
3. First time balloon dilatation
4. Removal of fibrous tissue
5. Second time balloon dilatation
6. Near normal tracheal shape and size

Ample clinical data clearly demonstrated clear benefits of using Tritube and Evone, managing the difficult airway or during laryngeal surgery. The following benefits were found:

• Minimized contamination risk for healthcare professionals, due to a sealed airway⁸
• An unprecedented view of the intubated airway, due to the thin lumen ^2,5,6
• A large surgical exposure and hygienic and clear sight with non-moving vocal cords ^2,4–6
• Easy intubation even in difficult airways due to the small outer diameter and malleable stylet ^2,3,9
• Awake intubation in patients with a difficult airway ^2,9
• Well tolerated when left in situ postoperatively, allowing patients to breathe and talk ^2,3,9
• More efficient ventilation, better oxygenation and CO2 removal^7,10,11

1. Piazza, C. et al. Long-term intubation and high rate of tracheostomy in COVID-19 patients might determine an unprecedented increase of airway stenoses: a call to action from the European Laryngological Society. European archives of oto-rhino-laryngology: official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS): affiliated with the German Society for Oto-Rhino-Laryngology – Head and Neck Surgery (2020) doi:10.1007/s00405-020-06112-6.
2. Kristensen, M. S., de Wolf, M. W. P. & Rasmussen, L. S. Ventilation via the 2.4 mm internal diameter Tritube® with cuff – new possibilities in airway management. Acta Anaesthesiol Scand 61, 580–589 (2017).
3. Kristensen, M. S. & Abildstrøm, H. H. Endotracheal video-laryngoscope guided intubation with a 2.4 mm cuff’ed tube and active expiration by a dedicated ventilator versus a standard tube/ventilator. A randomized single blinded study in patients with a predicted difficult airway. – A paradigm shift in airway management? Abstract published at Euroanaesthesia 2019 3755, (2019).
4. Schmidt, J. et al. Flow-controlled ventilation during ear, nose and throat surgery: A prospective observational study. Eur J Anaesthesiol 36, 327–334 (2019).
5. Schmidt, J. et al. Glottic visibility for laryngeal surgery: Tritube vs. microlaryngeal tube: A randomised controlled trial. Eur J Anaesthesiol 36, 963–971 (2019).
6. Meulemans, J. et al. Evone® Flow-Controlled Ventilation During Upper Airway Surgery: A Clinical Feasibility Study and Safety Assessment. Front. Surg. 7, (2020).
7. Schmidt, J. et al. Improved lung recruitment and oxygenation during mandatory ventilation with a new expiratory ventilation assistance device: A controlled interventional trial in healthy pigs. Eur J Anaesthesiol 35, 736–744 (2018).
8. Nouraei, S. A. R., Girgis, M., Shorthouse, J., El-Boghdadly, K. & Ahmad, I. A multidisciplinary approach for managing the infraglottic difficult airway in the setting of the Coronavirus pandemic. Operative Techniques in Otolaryngology-Head and Neck Surgery 31, 128–137 (2020).
9. Pichi, B et al.  CORONAsteps for Tracheotomy in COVID-19 Patients: A Staff-Safe Method for Airway Management. Oral oncology. 2020;105:104682
10. Magasich-Airola, NP et al. Novel technique for safe tracheostomy during COVID-19 pandemic using Evone^® flow-controlled ventilation system. Int J Clin Pract. 2020 Nov 27;(epub).