Hyoepiglottic Ligament and Midline Vallecular Fold

by Terren Trott August 15, 2021

Reading Time: 2 minutes

The Pre-brief

The hyoepiglottic ligament and midline vallecular fold are key structures and targets in airway management for optimal glottic exposure. If you’re unfamiliar with its use, check out how to engage it here. However, admittedly, we don’t have data supporting the routine use of this mechanism.

Hypoepiglottic Ligament

The midline vallecular fold is the supportive tissue between the epiglottis and the base of the tongue, deep in the vallecula. It is classically taught as the target for placement of the MAC blade tip.

Brian Driver et al did a retrospective review to decide if this mantra of engagement in airway management stood true after careful scrutiny of previously recorded video intubations. Two reviewers, blinded to the outcome of this study, were asked if the intubator engaged the midline vallecular fold (the tissue overlying the hyoepiglottic ligament) and the resultant degree of glottic exposure. Intubations were performed using the CMAC standard geometry video laryngoscope with the ability to record intubations. Engaging the fold demonstrated a significantly higher correlation with a good Cormack-Lehane score but conversely no difference in percent glottic opening score.

While appropriately emphasized by the authors, engaging the midline vallecular fold usually improved visualization of the glottis but did not necessitate it. Other factors such as position have been well validated to improve glottic exposure, key to first pass success. This study is confounded by the factors that would lead to good versus poor engagement of the fold. It is possible that “easy” airways will have good glottic exposure regardless of fold engagement and “harder” airways will be challenging to engage the fold. Nonetheless, this is the first clinical data we have addressing the engagement of the midline vallecular fold.

The Debrief

The midline vallecular fold has anecdotally been the target for the tip of your mac blade yet no clinical studies have addressed the efficacy of engagement.
In a retrospective review, engagement of the fold yielded more frequent good Cormack-Lehane score.

References

Driver BE, Prekker ME, Levitan RM, Corajod J, Karl E, Smith AD, Reardon RF. Engagement of the Median Glossoepiglottic Fold and Laryngeal View During Emergency Department Intubation. Ann Emerg Med. 2021 Jun 22:S0196-0644(21)00312-7. doi: 10.1016/j.annemergmed.2021.04.024. Epub ahead of print. PMID: 34172299.