To investigate the causes of infected mastoid cavity after radical mastoidectomy in patients with otitis media, and to explore the key points in revisional radical mastoidectomy.

The clinical data of 35 patients with infected mastoid cavity after radical mastoidectomy for otitis media were retrospectively analyzed, including detailed medical history, imaging data, audiological data, surgical data, and postoperative recovery of the mastoid cavity and hearing.

Among the 35 patients with infected mastoid cavity after radical mastoidectomy, 34 (97.1%) underwent canal wall down mastoidectomy and tympanoplasty, and 30 (85.7%) underwent conchoplasty. During the operation, it was found that all patients had different degrees of incomplete mastoid profile and incomplete clearance of the lesions in the previous operation. There were 25 (71.4%) cases of cholesteatoma recurrence and 26 (74.3%) cases of high facial nerve ridge. The lesions were mainly located in the upper tympanum or the anterior tympanum space, in the posterior tympanum, around the base of the stapes, around the round window membrane or round window ridge, in the middle tympanum, in the tympanic antrum or the entrance, in the posterior air cells of facial nerve, and in the air cells around the labyrinth. After surgery, all the 35 patients had a dry mastoid cavity without recurrence.

The main reasons for infected mastoid cavity after radical mastoidectomy are: conchoplasty has not been performed in the previous operation, leading to a small ostium of the external auditory canal relative to the big mastoid cavity; some important anatomic areas are not exposed sufficiently for the purpose of avoiding surgical complications in the previous operation, leading to cholesteatoma residues in hidden areas. Canal wall down mastoidectomy is the first choice for revisional cases. The surgeon should profile the mastoid to form a saucer-shape cavity, thoroughly clean the lesions in hidden areas, and grind down the facial crest.