Conclusions: The facial nerve courses shown by preoperative CT imaging coincide with the surgical findings in most congenital aural atresia cases. CT scanning is critical in evaluation of a patient's candidacy for atresia surgery.
Objectives: To evaluate the diagnostic value of preoperative CT scanning of the facial nerve course in congenital aural atresia.
Subjects and methods: All inpatients (135 cases) with congenital aural atresia had routine preoperative CT examination. The facial nerve courses were observed in the operation and compared with the preoperative CT imaging.
Results: CT imaging showed that the mastoid portions of the facial nerves in 57% of cases (77/135) were located at the level of the round window, and 17% (23/135) were located at the levels of the oval window and the cochlea. Differential overlapping of the oval window by the facial nerve could also be shown in most of the cases. In the majority of cases (75%, 61/81) the tympanic portions of the facial nerve on CT imaging could be confirmed by surgical findings. In severe overlapping of the oval window or cases with anterior displacement, stapedectomy or tympanoplasty, respectively, could not be performed as usual.