Drug-induced sleep endoscopy (DISE) has demonstrated that some patients may have the epiglottis playing a significant role in contributing to their obstructive sleep apnea, separate from other structures like the tongue or oropharyngeal lateral walls that secondarily cause airway obstruction behind the epiglottis. The VOTE Classification that Winfried Hohenhorst, Nico de Vries, and I developed in 2011 to describe DISE findings specifically included the “E” for epiglottis because epiglottis-related obstruction is somewhat common. It turns out that DISE may be the only obstructive sleep apnea surgical evaluation technique that identifies the epiglottis as important in some patients, such that a suspicion of epiglottis-related obstruction may be a key reason to perform DISE before sleep apnea surgery. Whenever I give talks about DISE to other surgeons around the world, by far the most questions related to the epiglottis and how to treat epiglottis-related obstruction seen during DISE.

I am indebted to my patients who have been willing to contribute to science by providing consent for their inclusion in my research database. One of the benefits of my focus in obstructive sleep apnea surgery for my entire career and the research database is the ability to perform studies in large groups of patients. Recently, I performed a study of epiglottis-related obstruction during DISE in study participants over the last decade or so, and the results were recently accepted for publication in the journal JAMA Otolaryngology – Head and Neck Surgery.

The VOTE Classification differentiates two types (configurations) of epiglottis-related obstruction: anteroposterior (front-to-back) and lateral (side-to-side). For each configuration, the airway obstruction can be of a partial or complete degree. To understand what patients may benefit from epiglottis surgery and what type of epiglottis surgery might work best for a given patient, it is important to understand potential differences between these configurations and, perhaps, the importance of the degree of obstruction during DISE.

For the study, I included the configurations of epiglottis-related obstruction together and then separately. This study included individuals with obstructive sleep apnea but no previous surgical treatment who underwent DISE performed by me over the past decade. Of note, I did not include all study participants in the database for this study, as it started as I began to note whether or not there was a finding during awake office flexible endoscopy that I called posterior displacement of the epiglottis off the tongue base. This finding is defined by the ability to look into the space between the tongue and epiglottis easily with the flexible endoscope up high in the throat. This was something that may be seen during the flexible fiberoptic endoscopy that I perform in the office (before proceeding to DISE) and was a finding that I felt was associated with epiglottis-related obstruction during DISE. I started collecting this information on posterior displacement of the epiglottis in the research database only about 10 years ago, so this study was limited to that period of time.

Among 708 study participants, this study of the prevalence of and risk factors for epiglottis-related obstruction showed:

• Epiglottis-related obstruction occurred in 16%, including 100 (14%) anteroposterior and 13 (1.8%) lateral configurations.
• Posterior displacement of the epiglottis off the tongue base was independently associated with both the anteroposterior and lateral configuration of epiglottis-related obstruction.
• Anteroposterior epiglottis-related obstruction was associated with male sex, lesser palate-related (velum-related) obstruction, and older age. There were only weak associations with findings related to other VOTE structures, including lesser oropharyngeal lateral wall-related obstruction.
• Lateral epiglottis-related obstruction was only seen in males and in those with oropharyngeal lateral wall-related obstruction. It was associated with greater oropharyngeal lateral wall-related obstruction but was not associated with obstruction related to other VOTE structures.

Why is this study important?

Epiglottis-related obstruction occurs often but is less common than obstruction related to other VOTE structures. This finding is not new, as it has been demonstrated in previous studies. However, there are two findings that have not been seen previously. First, there is an awake flexible fiberoptic examination finding (posterior displacement of the epiglottis off the tongue base) that is associated with both anteroposterior and lateral epiglottis-related obstruction. It may not be necessary to perform DISE in all patients with obstructive sleep apnea before surgery, but this awake examination finding might lead a surgeon to perform DISE before surgery if they are considering possible epiglottis treatment.

Secondly, the anteroposterior and lateral configurations of epiglottis-related obstruction appear to have different risk factors, consistent with their being different entities. This would suggest that they should be considered separately, both in terms of their significance (do they need treatment?) and their treatment (what is the best treatment?). Personally, my takeaway is that treatment of lateral epiglottis-related obstruction is unlikely to be helpful without resolution of oropharyngeal lateral-wall related obstruction (often with weight loss or, potentially, hypoglossal nerve stimulation).

What is clear is that we still do not have all the answers, but my hope is that large studies like this one can focus on important clinical questions to improve surgical treatment outcomes and benefit patients.