Mastoid condition and clinical course of cholesteatoma.

This study was carried out to establish which type of cholesteatoma is controllable by conservative treatment from the viewpoint of mastoid ventilation. We examined the area of the air cell system and airspace (aeration) in the mastoid cavity by computed tomography and eustachian tube (ET) function by inflation-deflation test in 20 ears (20 patients) with severe attic retraction for over 12 months (retraction pocket group), 16 ears (16 patients) with cholesteatoma which could be controlled only by conservative treatment for over 12 months (nonsurgical group) and 43 ears (43 patients) which required surgery within a year in spite of similar conservative treatment (surgical group). The size of the mastoid air cell system in the retraction pocket group, nonsurgical group and surgical group was 2.9 +/- 1.3, 1.9 +/- 0.7 and 1.5 +/- 0.9 cm(2) on average, respectively, with no significant difference between both cholesteatoma groups (nonsurgical and surgical group). While aeration was observed in the mastoid in 17 of 20 ears (85.%) in the retraction pocket group and in 12 of 16 ears (75.0%) in the nonsurgical group, aeration was present only in 9 of 43 ears (26.5%) in the surgical group, being significantly less in the surgical group than in the nonsurgical group and the retraction pocket group. In all ears in the retraction pocket and nonsurgical groups, and 19 of 30 ears in the surgical group, ET function was poor, there being no significant difference among the three groups. The present clinical observations suggest that progressiveness of cholesteatoma could be related to the ventilatory conditions in the mastoid rather than ET function, and that conservative treatment may be effective when ears with cholesteatoma have aeration in the mastoid.