This chapter reviews the role of the epiglottis in obstructive sleep apnea (OSA) and surgical management of its obstructive capacity. Although it has been well recognized for years that multiple levels of obstruction are responsible for OSA, most authors focus on nasal, retropalatal, and retroglossal obstruction as the three major sites of collapse. Relatively little literature has been devoted to the role of the epiglottis in contributing to OSA. With the advent of more widespread use of drug-induced sleep endoscopy (DISE), this anatomic site has begun to receive more attention ( Fig. 54.1 ).
Catalfumo et al. published an early study regarding the role of the epiglottis in OSA, based upon awake endoscopy. In their study, epiglottic collapse was estimated to be involved in 12% of patients with OSA. Using DISE, many subsequent studies have demonstrated an increased incidence of epiglottic involvement in OSA. Torre et al. have done a thorough review of this literature and cite studies identifying percentage of epiglottic collapse ranging from 15% to 73.5%. Authors defined epiglottic collapse in various ways. For example, Woodson found an incidence of 15% isolated epiglottic collapse on DISE, whereas Golz et al. found an incidence of 14.4% isolated epiglottic collapse and 11.3% multiple-level collapse (including epiglottis). Other authors defined anteroposterior collapse and lateral collapse as relevant in determining success of surgical outcome.
There is evidence that epiglottic collapse may be a determinant of continuous positive airway pressure (CPAP) failure, as the positive pressure may force the collapsing epiglottis further into the laryngeal airway. For example, Dedhia et al. demonstrated that 15% of adult patients unable to tolerate CPAP had primary epiglottic obstruction of the hypopharynx. Particularly in the circumstance of isolated collapse, the epiglottis must be considered as an independent variable in determining the proper surgical strategy to manage OSA patients. Several surgical strategies are discussed next: epiglottopexy with or without lingual tonsillectomy and partial laser epiglottectomy.
1
Indications
Determination of which OSA patient is appropriate for epiglottic surgery may be best determined by office indirect exam and DISE. Indirect exam is useful for assessing degree of lingual tonsil hypertrophy, as well as the anterior to posterior dimension of the oropharynx. DISE will determine the dynamic aspect of epiglottic anatomy during sedation—an excellent indicator of what is happening during sleep. During DISE, if epiglottic prolapse into the larynx is noted in isolation, a partial laser epiglottectomy may be sufficient (Image 1, Video). If there is contribution to the epiglottic collapse from lingual tonsillar hypertrophy, then lingual tonsillectomy must also be considered (Image 2).
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Contraindications
Patients with prior swallowing difficulties, in particular during the pharyngeal phase of swallowing, are not candidates for epiglottic surgery. If there is question regarding this, a barium swallow should be performed to rule out aspiration or penetration before considering the procedure. Because these procedures are done endoscopically, the patient must be able to be positioned with good laryngoscopic visualization of the epiglottis. Anatomic considerations that inhibit exposure may render these procedures undoable.
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Alternative Treatment Options
Patients with true epiglottic prolapse will likely not respond well to CPAP, as positive pressure ventilation will force the epiglottis farther down into the airway. If the sleep apnea is relatively mild, a dental repositioning device may be sufficient to overcome partial collapse ( Fig. 54.2 ).
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Technique 1: Epiglottopexy With or Without Lingual Tonsillectomy
4.1
Positioning
The patient is orally or nasally intubated with a reinforced endotracheal tube, and a protective tooth guard is placed. The base of the tongue may be exposed with a variety of retractors or laryngoscopes, best determined by the operating surgeon’s familiarity with the device. Examples of such retractors include the Lindholm laryngoscope, the Feyh–Kastenbauer retractor, and the Dingman retractor. Visualization for the procedure may be accomplished with an endoscope, microscope, or robot-assisted camera. A protective eye shield for the patient is employed to ensure that the eyes are not inadvertently hurt during the procedure.
4.2
Instruments
For the epiglottopexy, a Bovie knife, coblator, or CO 2 laser is used for demucosalization of the lingual surface of the epiglottis and tongue base. Suturing is accomplished with absorbable suture such as 4-0 Vicryl on a tapered needle.
For the lingual tonsillectomy, if using the DaVinci robot, the lingual tonsillectomy is performed with a Maryland retractor and Bovie knife or CO 2 laser. If using an endoscope or microscope, the coblation wand is used with accompanying suction irrigation. Cassano has reported a concise description of this technique.
4.3
Surgical Approach
If necessary, the lingual tonsillectomy is performed first. The retractor often needs to be repositioned during this portion of the procedure to achieve maximal resection. If using the robot, a 0-degree endoscopic camera is usually sufficient for visualization, though a 30-degree scope may be necessary for patients with small oral cavities or retrognathia. An en bloc resection of the lingual tissue at the tongue base is performed, working across the circumvalette papilla, to midline in the valecula, then lateral to the glossopharyngeal sulcus and then back up to the original incision. This is then repeated on the opposite side. With the coblator, the coblation setting is at 8, and lingual tonsillar tissue is removed piecemeal, with appropriate adjustments in the retractor for maximal visualization and resection ( Fig. 54.3 ).
