PERSISTENT OTITIS-MEDIA WITH EFFUSION - A NEW EXPERIMENTAL-MODEL

Objectives/Hypothesis: Numerous mechanical animal models for the creat ion of otitis media with effusion (OME) have been described since the 1920s, However, there are many problems associated with these models, including high infection rates, unreliability, and high resolution rat es. The aim of the current study was to create a suitable mechanical a nimal model that would produce a sterile and long-lasting effusion, St udy Design: A new technique using an external surgical approach on spe cific pathogen-free rats is described. Method: The eustachian tubes of 56 rats were obstructed in the mid portion along the skull base with gutta percha, Results: All animals developed an effusion within 1 week of the procedure. The resolution rate was 8%, with 80% maintaining st erile effusions for up to 1 year. Conclusions: This new procedure for an OME model has proved consistently reliable in creating a persistent and long-lasting effusion, It has a low infection rate and should ben efit future studies on the prolonged effects of OME on the tympanic me mbrane and middle ear.