Using high resolution computed tomography to evaluate middle ear cleft aeration of postoperative cholesteatoma ears.

BACKGROUND: Middle ear cleft mucosa and mastoid air cells are important for middle ear cleft aeration. However, the postoperative cholesteatoma ears treated in traditional open or closed techniques are often complicated by an atelectatic condition. In order to preserve the healthy mastoid air cells and also eradicate the cholesteatoma completely, we treated cholesteatoma ears by "tailored mastoidectomy with cartilage obliteration of the open cavity." METHODS: We used high resolution computed tomography (HRCT) to evaluate middle ear cleft aeration of postoperative cholesteatoma ears. Statistical analysis were used to investigate the correlation between postoperative milddle ear cleft aeration and associated clinical factors such as middle ear mucosa condition found intraoperatively (intact or defective), stage of cholesteatoma, level of mastoid pneumatization, range of cartilage obliteration, and tympanoplasty type. RESULTS: Forty-four cholesteatoma ears of forty-three patients (aged 13 to 74 years) underwent tailored mastoidectomy with cartilage obliteration of the open cavity from 1988 to 1998. Aeration of the middle ear cleft was evaluated using HRCT performed in a mean of 6.77 years after surgery. There was no aeration in 10 ears (22.7%), aeration only in the tympanic cavity in 19 ears (43.2%), and aeration in both the tympanic and mastoid cavities in 15 ears (34.1%). There were 26 ears (59.1%) with intact and healthy mucosa and 18 ears (40.9%) with defective mucosa. The correlation between the mucosal condition and recovery of middle ear cleft aeration was significant (r = 0.6855, p < 0.001). Recovery of aeration was negatively correlated with the stage of cholesteatoma (r = -0.4951, p = 0.0156) and positively correlated with the level of postoperative mastoid pneumatization (r = 0.8036, p < 0.001). CONCLUSIONS: Preserving healthy middle ear cleft mucosa and uninvolved mastoid air cells during cholesteatoma surgery enables gas-exchange through the remaining mucosa and maintains the pressure buffering effect of the mastoid, both of which are important for recovery of middle ear cleft aeration. HRCT is useful for the postoperative evaluation of middle ear cleft aeration.