Effect of tympanostomy tubes on the pathogenesis of acute otitis media.

Intubation of the tympanic membrane as a treatment for acute otitis media is extremely controversial. This study was designed to determine the effect of tympanic membrane intubation in an experimental model for acute purulent otitis media. The right tympanic membrane of the chinchilla was intubated with Paparella Type I tympanostomy tubes. This procedure was followed in seven days by nasopharyngeal inoculation of Streptococcus pneumoniae and in an additional three days by nasopharyngeal inoculation of influenza A virus. Nasopharyngeal inoculation with these microorganisms results in acute purulent otitis media in 70 per cent of animals. The presence of the tympanostomy tubes did not reduce the incidence of clinical otitis media, nor did it reduce the pathologic changes within the middle ear space. The tympanostomy tubes did, however, significantly reduce the incidence and severity of pathologic changes in the subepithelial space of the middle ear mucosa.