Sensorineural hearing loss following chronic ear surgery.

The incidence and characteristics of postoperative sensorineural hearing loss were analyzed in 2,303 cases of chronic otitis and its sequelae, representing our total series from 1965 to 1980. Sensorineural hearing loss occurred in a total of 1.2% of cases: 0.5% became totally deaf, and 0.7% acquired a high tone loss, most often at 4 kHz only. The incidence was highest in congenital malformations, granulating otitis and cholesteatoma, mastoidectomy (especially canal-down), and during the period from 1965 to 1974. The most common causes of anacusis were removal of cholesteatoma from the semicircular canal and removal of the fistula membrane. Different types of severe high tone loss are described and, in addition, 19 patients with mild high tone loss are discussed.