High-resolution computed tomography evaluation of congenital aural atresia - how useful is this?

To depict various temporal bone abnormalities on high-resolution computed tomography in congenital aural atresia patients, and correlate these findings with auditory function test results and microtia subgroup.

Forty patients (56 ears) with congenital malformation of the auricle and/or external auditory canal were evaluated. Auricles were graded according to Marx's classification, divided into subgroups of minor (grades I and II) and major (III and IV) microtia. Other associated anomalies of the external auditory canal, tympanic cavity, ossicular status, oval and round windows, facial nerve, and inner ear were evaluated.

Minor and major microtia were observed in 53.6 and 46.4 per cent of ears respectively. Mean hearing levels were 62.47 and 62.37 dB respectively (p = 0.98). The malleus was the most commonly dysplastic ossicle (73.3 vs 80.8 per cent of ears respectively, p = 0.53). Facial nerve (mastoid segment) abnormalities were associated (p = 0.04) with microtia subgroup (80 vs 100 per cent in minor vs major subgroups).

Microtia grade was not significantly associated with mean hearing levels or other ear malformations, except for external auditory canal and facial nerve (mastoid segment) anomalies. High-resolution computed tomography is essential in congenital aural atresia, before management strategy is decided.