Tympanostomy tubes prevent the development of experimentally induced purulent otitis media.

Cleavage of the soft palate will cause purulent otitis media bilaterally in 100% of experimental animals (the rat) within 2 weeks. In this model a tympanostomy tube was inserted unilaterally. At 2, 7, and 21 days after the surgery the middle ear status was mapped in the otomicroscope and microbiological samples collected from the middle ear cavities and the nasopharynx. All intact ears became infected and developed purulent otitis media. Most of the tubulated ears exhibited normal middle ear cavities and remained culture negative. The few ventilated ears which were infected, however, showed a lower bacterial count than the corresponding intact ear. Thus in this model the insertion of a tympanostomy tube prevents the purulent otitis media from occurring.