The pharyngeal end of eustachean tube is normally closed. It usually opens temporarily during swallowing and yawning during which time middle ear drainage and pressure equalisation takes place. Abnormalities involving this opening mechanism may lead to middle ear pathologies like otitis media with effusion.
Patulous eustachean tube is a difficult entity to treat. The phenomenon of autophony which is caused by this condition is a difficult entity to treat. Patients have been driven to sucide because of this problem.
Patulous eustachean tube can be identified by the presence of the following features:
Hearing of self breathing
Sonotubometry is used to identify this condition.
Causes of patulous eustachean tube:
1. Weight loss (chronic)
2. Wasting disorders
3. Chronic inflammation followed by tissue atrophy at the pharyngeal end of eustachean tube
Various surgical modalities have been attempted with very little success.
Role of nasal topical instillation of physiological saline:
Instillation of physiological saline has been proved to be beneficial in nearly 60% of these patients. This therapy can be continued till there is sufficient weight gain which could obviate the need for this medication. Instillation of saline in the pharyngeal end of eustachean tube may cause it to close. This effect should be considered to be purely temporarly till normal saline is present close to the pharyngeal end of eustachean tube. The same can be instilled again if symptoms recur. Physiological saline administration can be continued till there is spontaneous recovery which is also common. Simple weight gain can obviate the symptoms.