Causes of failure of mastoidectomy for chronic otitis media.

The operative findings of 66 patients who underwent revision mastoid surgery for recurrent chronic otitis media were analyzed for the causes of failure of the primary procedures. Recurrent cholesteatoma was found in 41% of the canal wall down and 70% of the canal wall up procedures requiring revision. Additional causes of failure included granulation tissue in unexenterated cells, particularly in the tegmental cells (41% of all cases and 64% of cases without cholesteatoma) and cells of the sinodural angle (38% of all cases and 58% of cases without cholesteatoma). The need for thorough exenteration of cells, particularly the tegmental cells and cells of the sinodural angle, mastoid tip, and facial recess, and the importance of lowering the facial ridge in canal wall down procedures were stressed. Following these principles, the success rate in creating a dry ear in 48 patients who had undergone from one to three previous mastoid procedures was 85% (mean follow-up three years).