Epiglottic trapdoor
A 28-year-old man presented to his GP with daytime somnolence and witnessed sleep-disordered breathing. His partner reported episodes of apnoea followed by tachypnoea and apparent choking episodes. He had a BMI of 26, and was otherwise well. He had no nasal symptoms, and nasal and oropharyngeal examination was normal. He was referred to his local sleep unit, where PSG demonstrated severe OSA, with an AHI of 32. He was commenced on CPAP treatment and initially tolerated this well.
Five years later, during a routine CPAP appointment, he reported that he had been having more difficulties. His CPAP pressures had been high throughout his treatment, but after recent dental work he was having increasing leaks from the mouth, which woke him up. He was unable to tolerate a full face mask. He was using the CPAP increasingly less frequently. He asked whether there were any alternatives to CPAP treatment. Examination and daytime somnolence were unchanged.
1 What investigations would you consider?
2 What are the options for management?
3 Are there any potential side effects of this treatment that should be monitored?
1. What investigations would you consider?
It is possible that, over time, sleep parameters will change. Apnoea indexes are relatively likely to worsen over time (OSA is more common in an older age group). Furthermore, change of weight or redistribution of fatty tissue may change the sleep quality. A repeat sleep study could therefore be considered in order to quantify the extent of the sleep-disordered breathing at that time.
Anatomical assessment of the upper airway during sleep would allow the site (or sites) of obstruction to be ascertained. This could take the form of sleep nasendoscopy/drug-induced sleep endoscopy, imaging studies or an apnoeagraph.
Empirical management with an MAS is also an option to see if anterior movement of the mandible and the tongue base would improve the sleep-disordered breathing. Generally, these devices are able to move the tongue base 5–6 mm anteriorly.
An MAS was well tolerated, but produced no improvement in symptoms. The patient underwent sleep nasendoscopy. During the sleep nasendoscopy, it was clear that the point of obstruction was at the epiglottis. The epiglottis prolapsed with inspiration such that the tip pressed against the posterior pharyngeal wall, and the body of the epiglottis obstructed the retroglossal airway almost totally. This is referred to as ‘epiglottic trapdoor phenomenon’.
2. What are the options for management?
CPAP treatment could be persevered with. An MAS had failed, but more definitive movement of the mandible and maxilla in the form of mandibular maxillary advancement could be considered. Wedge excision of the midline of the epiglottis was also an option.
The patient opted to undergo wedge excision of the epiglottis. The procedure was uneventful, and improved the sleep-disordered breathing significantly. A sleep study performed four months post-operatively demonstrated that the AHI had decreased to 2.3, and the patient was significantly less somnolent.
3. Are there any potential side effects of this treatment that should be monitored?
The epiglottis is most important for the prevention of aspiration during swallowing. Whilst this role is frequently overestimated (the tongue base is relatively much more important in preventing aspiration), the possibility of significant aspiration is something that should be closely monitored. Suspected aspiration can be assessed using a flouroscopic water-soluble contrast swallow.
Learning points
OSA may occur as a result of obstruction at any point in the upper airway.
Obstruction at the tongue base can be managed with CPAP, a MAD/MAS or surgically.
A balance has to be made between maintaining the airway during sleep and preserving pharyngeal structures that are important in swallowing.