Three clinical studies were performed to investigate the effects of
adenoidectomy on
otitis media with effusion (OME), especially with regard to eustachian tube (ET) disfunction and
sinusitis, which often accompanies OME. In the first study, the audiograms, tympanograms, and ET ventilatory functions of 78 adenoidectomized patients (121 ears) and 54 non-adenoidectomized patients (63 ears) were compared over 6 months. The audiograms and tympanograms of the adenoidectomized group showed significant improvement; however, no difference in passive tubal opening pressure was noted despite an improvement in positive pressure equalizing function observed in the adenoidectomized group at 6 months after the operation. In the second study, tubal passive resistance (PR) and the ratio of passive resistance to active resistance (PR/AR) were compared before and 1 month after
adenoidectomy using the forced response test (12 subjects, 12 ears). Neither PR nor PR/AR had significantly improved after the operation. In the third study,
sinusitis improvement in 45 adenoidectomized patients 6 months after the operation was evaluated in comparison with 33 non-adenoidectomized patients. This condition was found to have improved significantly in the adenoidectomized group. Overall,
adenoidectomy appeared effective in reducing the incidence of OME and
sinusitis, and in improving the active ventilatory function of the ET without causing changes in the tubal passage. It is conceivable that tubal active ventilatory function was improved due to a reduction of
inflammation and pollution around the nasopharynx by
adenoidectomy, and that the effect of adenoid mass on the ET is minimal.