Acute mastoiditis after a combined approach tympanoplasty operation.

Four of 112 ears on which a combined approach tympanoplasty (CAT) operation was performed had acute mastoiditis six to 24 months after operation. All four patients were younger than 13 years. This represents 12.5% of acute mastoiditis cases after CAT operations in this age group, or 3.5% of the total group. On reoperation, all four ears expressed pus under pressure in the mastoid cavity. There was also fibrosis and granulation tissue blocking the attic inlet. It is probable that the cause of the acute mastoiditis may be related to this partial or total stenosis. Two of the patients were found to have an aerated, noninflamed tympanic cavity, and only in two was the acute mastoiditis associated with residual cholesteatoma.