Blast injury of the ear.

The course of middle ear injuries secondary to blast effect was evaluated in 147 soldier-patients (210 ears) during the years 1967-1986. All perforations were in the pars tensa of the tympanic membrane. Ossicular chain interruption (11 ears) was associated mainly with dislocation of the incudo-stapedial joint. Mixed-type hearing loss was most prevalent (37%). Spontaneous closure occurred in 155 ears (73.8%), most of them (65.5%) within a 3-month period. Seven ears (3.3%) developed simple chronic suppurative otitis media; in 10 (4.8%), an invasive cholesteatoma developed, and in 6 others (2.8%), epithelial pearls were encountered behind an intact eardrum. Thirty-two patients were treated by immediate patching of the perforated drum, with an 84% rate of spontaneous closure; no cholesteatoma developed among this group, emphasizing the need for immediate patching. Tympanoplasty is recommended 1 year following the injury, and a 4-year follow-up period for detection of late complications is also recommended.