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

To evaluate the histopathological effect of intranasal pulmonary surfactant (PS) on the eustachian tube (ET) in guinea pigs with otitis media with effusion (OME).

Randomized control trial.

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.

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.

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.