Pathological study of otitis media with effusion after treatment with intranasal pulmonary surfactant.

ABSTRACT

OBJECTIVES/HYPOTHESIS: To evaluate the histopathological effect of intranasal pulmonary surfactant (PS) on the eustachian tube (ET) in guinea pigs with otitis media with effusion (OME). STUDY DESIGN: Randomized control trial. METHODS: Nonviable heat-killed Hemophilus influenzae solution was injected into the tympanum of guinea pigs by a trans-eardrum approach to establish OME. Guinea pigs were divided into four groups normal controls (group A), untreated OME (group B), saline-treated (group C), PS-treated (group D). The response threshold of the guinea pigs was measured by auditory brainstem response (ABR), and data were analyzed by one-way analysis of variance. The histopathological changes in the osseous, cartilaginous, and muscular portions of the ET were observed systematically by light microscopy. RESULTS: The ABR threshold in OME group B was raised significantly compared with normal group (A). The response in saline-treated group C was not statistically significantly different compared with OME group B. Seven days after intranasal dripping of pulmonary surfactant in PS-treated group D, the response threshold showed at statistically significant decrease compared with OME B and saline-treated C groups. In OME group B and saline-treated group C, mucosa showed swelling with goblet cell hyperplasia, and cilia were irregularly arranged. In PS-treated group D, there was slight mucosal swelling with fewer goblet cells, and cilia were regularly arranged, similar to the normal group A. CONCLUSIONS: The findings of the study indicate that intranasal pulmonary surfactant drops have protective and hyposecretory effects on the mucociliary system of the ET in guinea pigs suffering from OME.