Evolution of middle ear changes after permanent eustachian tube blockage

OBJECTIVE: To develop a valid animal model for otitis media with effusion (OME). DESIGN: Forty specific pathogen-free Wistar rats underwent a procedure based on the permanent obstruction of pharyngeal eustachian tube by means of electrocoagulation without any manipulation. SETTING: Ear Research Group, Department of Otorhinolaryngology, Puerta de Hierro Hospital, Universidad Autonoma de Madrid, Madrid, Spain. MAIN OUTCOME MEASURES: The assessment of OME by otoscopy and tympanometry. The rats were humanely killed at 15 and 90 days, and temporal bones were obtained and processed for histopathologic study. RESULTS: The histopathologic study of the temporal bones demonstrated the occurrence of chronic effusion and mucosal changes owing to mucoperiosteal enlargement. CONCLUSIONS: Comparison with other experimental models was made. Our animal model was consistent and reproducible and resembled human OME.