One of the widely used recent treatments for secretory otitis media is to insert the -ventilating tube into the middle ear cavity. The purpose of using the ventilating tube is to make the pathology of the middle ear reversible by ventilating the middle ear cavity and -draining the effusion of the middle ear, and also to regain normal physiology of the middle ear by recovering the Eustachian tube function during the treatment.
However, it is rarely studied pathologically that whether the middle ear mucosa undergoes a reversible change and how it recovers when ventilation tubes are used.
Auther induced an experimental secretory otitis media by obstructing the Eustachian tube in rabbits and then ventilating tubes were inserted in the middle ear in several different -stages. The character of the effusion and the mucosal findings of the middle ear were -observed by a light microscope. Ultrastructural findings were also studied using electron microscope.
The results obtained were as followings:
1. In case that intubation was made immediately after Eustachian tube obstruction, middle ear effusions were not found comparing with other cases that intubation was late after Eustachian tube obstruction.
2. The mucoid effusion induced by Eustachian tube obstruction showed a tendency to change into serous effusion after 14 days intubation.
3. In case that intubation was in 7 days after Eustachian tube obstruction, findings of mucosa such as increased number of goblet cell and inflammatory reaction tend to be decreased, comparing with other cases that intubation was made; after 14 days.
4. After intubation, the nonciliated or secretory epithelium of the hypotympanic bulla of
the transitional zone of the middle ear mucosa was replaced with ciliated celIF..
5. After intubation, the secretory cells, i.e., light granulated cells were markedly decreased´ and dark granulated cells were rarely observed comparing with cases without intubation.
6. In all cases of intubation, bacteria was isolated in middle ear effusion.
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