Inner ear anomalies in children with isolated unilateral congenital aural atresia.

OBJECTIVES/HYPOTHESIS: We aim to define the frequencies of anomalies of the inner ear, oval window, and round window ipsilateral to isolated non-syndromic unilateral aural atresia.

METHODS AND MATERIALS: Retrospective case series. We reviewed high resolution computed tomography scans of the temporal bones of 70 children with isolated non-syndromic unilateral congenital aural atresia. Scans were reviewed according to the Jahrsdoerfer criteria and further evaluated for anomalies of the vestibule, semi-circular canals, cochlea, internal auditory canal and vestibulocochlear nerve.

RESULTS: Inner ear dysplasia was seen in two of 70 atretic ears: one with a dysmorphic lateral semicircular canal and another with a large vestibule assimilating the lateral semicircular canal. Abnormalities of the oval window and round window ipsilateral to the atresia were identified in 21% (15) and 7% (5), respectively, of the atretic ears. Oval window and round window abnormalities were associated with disproportionately lower Jahrsdoerfer scores compared to aural atresia patients without these abnormalities (P < 0.001 and P = 0.04, respectively).

CONCLUSION: Compared to studies that included syndromic or bilateral atresia cases, we found inner ear and oval window abnormalities less common in children with isolated non-syndromic unilateral aural atresia. However, round window anomalies seem to occur at about the same frequency.