Histopathology of tubotympanum of children with otitis media treated with ventilation tubes.

We studied histopathologically the middle ear (ME) and eustachian tube (ET) in 12 temporal bones from eight children who had had otitis media with effusion that had been treated with ventilation tubes (VTs) for 3 weeks to 11 months. In the ME, 1) only a minimal amount of effusion was seen in most of the ears treated for 3 months or longer, 2) the severity of submucosal inflammation almost paralleled the amount of effusion, 3) the amount of granulation tissue on the tympanic membrane at the site of VT insertion also seemed to parallel the degree of ME inflammation, and 4) epidermal ingrowth was seen in both of the two ears treated with VTs for 10 and 11 months. Pathologic findings in the ET were generally more severe than those in the ME, but tended to decrease with longer VT therapy. In two ears with VTs obstructed by inflammatory granulomatous tissue, the entire ME cavity was filled with effusion, and dense effusion plugged the bony portion of the ET. The results of this study indicate that 3 to 11 months of treatment with a VT is effective for reversing the ME effusion and for reducing inflammation in the ME. Some inflammation may be left in the ET, however, even with 11 months of VT therapy, and epithelial ingrowth should be watched for when VT therapy lasts 10 months or longer. Despite the fact that most of our temporal bones were from infants and children who had a variety of systemic diseases or disorders and in whom their terminal event might have contributed to our findings, we consider these temporal bones to be informative.