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Case Report

Successful intubation of a patient with a supraglottic tumor using a novel articulating introducer for precision tracheal access

Keefe, Katherine R. MDa; Cannon, Richard B. MDa; Runnels, Sean T. MDb,

Author Information
Journal of Head & Neck Anesthesia: May 2021 - Volume 5 - Issue 1 - p e31
doi: 10.1097/HN9.0000000000000031

Abstract

Tracheal intubation requires solving 2 problems: visualization of the glottis and navigation of an endotracheal tube (ETT) into the trachea. Even when visualization is solved, navigation around a tumor can remain a problem.

We report the successful intubation of a patient with a supraglottic tumor using a modified combined technique (CT) involving a video laryngoscope (VL) for visualization in combination with a Total Control Introducer (TCI) (Through The Cords, LLC, Salt Lake City, UT) for precision tracheal access.

Airway management

A 68-year-old man with a 3 cm mass of the right tongue base, was scheduled for a lymph node biopsy. After discussion with the patient and surgical team it was decided to perform an asleep intubation with a VL combined with a TCI articulating introducer. The patient gave written permission for video of the airway management to be taken for educational and publishing purposes. Informed consent was performed. In the operating room, ASA standard monitors were placed and the patient was preoxygenated. Propofol and fentanyl were used for induction, effective manual ventilation was confirmed, and succinylcholine given. A VL (Glidescope with a hyper-angulated GL4 blade; Verathon) was placed and a grade 1 view attained. In this case, the tip of the blade was placed under the epiglottis. No attempt was made to reposition it into the vallecula (Supplemental Video 1, http://links.lww.com/JOHNA/A4). The tumor partially filled the upper right supraglottic VL field of view. A TCI was then placed along the right side of the VL blade and advanced until the tip appeared in the VL screen. As the introducer was advanced, the tip was articulated posteriorly to pass under the tumor; then anteriorly into the glottic opening, then posteriorly into the trachea avoiding the anterior tracheal wall. Advancement stopped when the green depth band was adjacent to the vocal cords, indicating that the tip was in the mid-trachea. The handle of the TCI was released and removed. The ETT was then railroaded over the introducer into the trachea. The shaft of the TCI was removed leaving the ETT in place. The ETT balloon was inflated and endotracheal intubation was confirmed with end-tidal CO2 and bilateral auscultation of the chest.

Discussion

The ability to precisely navigate into the trachea when intubating patients with supraglottic tumors is important. Many stylets and introducers are malleable or rigid without precise navigational abilities. If the curve does not fit, it cannot be changed while in use leading to difficult access to the trachea1,2.

Precision tracheal access requires 2 features in an introducer. A controllable articulating tip, and a flexible shaft that can conform to the upper airway without restricting tip articulation.

A flexible fiberoptic bronchoscope (FOB) has both features enabling precision tracheal access. It can be used alone or in combination with a VL. This CT uses a VL for visualization in combination with a FOB for precision tracheal access. In some cases, the FOB is used for visualization as well as navigation. In some cases it is used simply as a dynamically shapable stylet3. Both techniques have advantages and disadvantages.

We report the successful intubation of a patient with a supraglottic tumor using a modified CT; VL for visualization in combination with a TCI articulating introducer for precision tracheal access and intuitive tracheal depth control4.

The TCI has no optical capability (Fig. 1). It does have several unique features: (1) A tip that can be anteflexed to 90 degrees and retroflexed to 35 degrees allowing the operator to change the shape of the introducer during use. Articulation is controlled by a removable pistol-grip handle. (2) A flexible shaft that conforms to the upper airway without restricting tip articulation. (3) Visually distinct depth bands printed on the tip and distal shaft of the introducer allowing intuitive understanding of tip depth in the trachea without looking away from the VL display. The range of tracheal lengths in adult females and males is well described5. The depth bands of the introducer are calibrated based on these ranges. When viewed in relation to the glottis on the VL screen, each band conveys an intuitive and qualitative understanding of tip placement in the trachea. If the red band is adjacent to the glottis, the tip may be too deep, nearing or passed the carina, risking injury to the lower airways or lungs. If the green band is adjacent to the glottis, the tip is safe in the mid-trachea. If the white band (new TCI model) or yellow band (old TCI model used in this case) is adjacent to the glottis the tip may be in the upper third of the trachea risking a failed intubation (Fig. 1).

Figure 1
Figure 1:
The Total Control Introducer consists of a flexible shaft with a removable pistol-grip handle that allows for active articulation of the introducer tip. The shaft has 3 distinct colored bands that correspond to its’ depth in the tracheas assessed at the glottis. Note: this photo depicts the most recent model which has been updated since the filming of this video; it now has a white zone instead of a yellow zone and a shorter front shaft.

Once navigated into the trachea and properly placed, the pistol-grip handle is removed allowing railroading of the ETT over the introducer shaft into the trachea.

Both the VL+FOB and VL+TCI presented in this case report, offer several advantages over FOB alone.

Frist, VL may offer easier visualization of the glottis compared with FOB alone. Once in place, the field of view of a VL is fixed and panoramic, whereas the field of view of the FOB is limited in scope, dynamic, and difficult to master.

Second, with FOB alone there is no visualization of the glottis once the FOB enters the trachea. The tip of the ETT may “catch” on the glottis or tumor during placement and not be seen. When combined with VL the passage of the ETT can be visually monitored as it passes over the introducer through the supraglottic space and glottic structures. While this may not prevent “tip catch,” it can allow immediate recognition and remedy of the problem. This may lower the risk of disruption of the tumor or damage to glottic structures. The VL blade tip itself may or may not be included in the visual field of the VL depending on the type of the device used. This may influence the risk of disrupting the tumor with the blade tip while obtaining a glottic view.

Finally, specialized conduits are sometimes used to protect the FOB from dependent secretions and/or debris that may contaminate the FOB lens as it traverses the posterior oral pharynx. The use of a VL alone for glottic visualization combined with a blind dynamic introducer (FOB or TCI) may decrease the need for specialized conduits. This may reduce the operator’s total mental task load, by decreasing the amount of equipment needing management and decreasing the potential mental distraction of a contaminated FOB lens. Increased metal task load during intubation has been hypothesized to increase risk of poor performance6.

The use of a TCI may offer advantages over the classic CT. First, the lax nature of the FOB requires 2 hands for placement requiring a second set of hands to place the VL. In contrast, the TCI is stiff enough to allow placement, precision tip control and advancement with only the right hand. This frees the left hand for VL placement allowing single-operator access to the trachea.

Secondly, the depth bands on the TCI shaft are designed to give continuous and intuitive understanding of introducer tip depth in the trachea during the procedure. Importantly, because tip depth is calibrated to the glottis instead of the tooth or lip, depth may be assessed without looking away from the VL display. This may reduce mental task load and risk of injury to the lower airways or lungs.

Lastly, FOBs are expensive and not always immediately available7. The lower cost (<$95 per use) of the TCI may improve availability of precision access to the trachea (personal communication with the TTCmed.com sales team).

Risks of airway introducers are well known. The most dangerous scenarios involve perforation of pharyngeal structures, tracheal perforation, bronchial perforation, and pneumothorax. The TCI has been used in over 2000 intubations without reported complications (personal communication with Wil Roberge, Chief Quality Officer, Through The Cords, LLC). When a VL is used for visualization, the use of a dynamic introducer for precise navigation into the trachea has been associated with a reduced airway injury rate when compared with static stylets3. Further studies are needed to better understand if this relationship exists with the TCI.

Interestingly, in this case the VL blade was not placed into the vallecula. Placement below the epiglottis risks creating a more difficult intubation by lifting the glottis. This can make navigation into the trachea more difficult despite an improved view8. In this case, the trachea was easily entered on the first attempt. The role of the TCI in mitigating this risk is unknown.

In conclusion, we report the first modified CT utilizing a novel articulating introducer in conjunction with a VL to successfully manage the airway of a patient with a supraglottic tumor. Further study is needed to understand the TCI’s effectiveness as an advanced intubation tool.

Conflict of interest disclosures

S.T.R. is the inventor of The TCI and holds shares in Through The Cords LLC. The remaining authors declare that they have no financial conflict of interest with regard to the content of this report.

References

1. Schechtman SA, Mathis M, Muller G, et al. A retrospective analysis of factors associated with difficult endotracheal tube passage with use of the hyper-angled GlideScope blade. J Head Neck Anesth 2019;3:e14.
2. Kleine-Brueggeney M, Greif R, Schoettker P, et al. Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a multicentre randomized controlled trial. Br J Anaesth 2016;116:670–9.
3. Mazzinari G, Rovira L, Henao L, et al. Effect of dynamic versus stylet-guided intubation on first-attempt success in difficult airways undergoing glidescope laryngoscopy: a randomized controlled trial. Anesth Analg 2019;128:1264–71.
4. Pollard J, Runnels S, Warrick C. First case report of intubation with a total control introducer and a hyperangulated video laryngoscope. A&A Pract 2020;14:e01310.
5. Cherng C-H, Wong C-S, Hsu C-H, et al. Airway length in adults: estimation of the optimal endotracheal tube length for orotracheal intubation. J Clin Anesth 2002;14:271–4.
6. Runnels S, Ferranti D, Davis AN, et al. The Utah model: mental bandwidth and strategic risk generation in COVID-19 airway management. Anaesthesia 2020;75:967–8.
7. Mouritsen JM, Ehlers L, Kovaleva J, et al. A systematic review and cost effectiveness analysis of reusable vs. single-use flexible bronchoscopes. Anaesthesia 2020;75:529–40.
8. Bacon ER, Phelan MP, Doyle DJ. Tips and troubleshooting for use of the GlideScope video laryngoscope for emergency endotracheal intubation. Am J Emerg Med 2015;33:1273–7.
Keywords:

Difficult airway; Intubation; Airway management; Combined technique

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Copyright © 2020 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The Society for Head and Neck Anesthesia.