Prospective blinded study of computed tomography in congenital aural atresia.

Objective: To report a preliminary descriptive study of new and refined anatomic considerations for computed tomography (CT) in congenital aural atresia (CAA).

Design/patients: Thirty-two temporal bone CT scans from 26 patients (6 bilateral cases) with CAA were graded in a prospective blinded manner with both Jahrsdoerfer's system and the new/refined anatomic considerations. In addition to Jahrsdoerfer's grading, new and refined considerations graded included the presence or absence of: (1) inferiorly displaced tegmen mastoideum, (2) malleus/incus complex directly lateral versus anterolateral to stapes, which may make surgical stapes access much more difficult, and (3) possible facial nerve obstruction of surgical access at two sites: oval window and middle ear.

Setting: Tertiary-care children's hospital.

Results: Inferiorly displaced tegmen mastoideum occurred in 5 ears (16%), the malleus/incus complex was directly lateral to the stapes in 12 ears (38%), the facial nerve possibly obstructed access to the oval window in 17 ears (53%), and it possibly obstructed access to the middle ear in 5 ears (16%).

Conclusion: New and refined anatomic/radiographic considerations for CT in CAA are reported for a series of temporal bones. The presence of these anatomic variants may influence the decision against atresiaplasty since these anatomic factors may possibly make atresiaplasty more difficult or impossible. Precise determination of atresiaplasty candidacy is important since Bone Anchored Hearing Aid is also a valuable option.