Usefulness of reconstructed 3D images for cochlear implantation in a case with a facial nerve anomaly

Facial nerve anomalies are a potential problem in patients with cochleovestibular malformations. A case of cochlear implant (CI) surgery in the presence of intra-temporalbone facial nerve bifurcation is presented. During the first surgery, the facial nerve bifurcation obscured the promontory and round window. It was difficult to perform cochleostomy because of the lack of landmarks of the basal turn of the cochlea, and the first surgical attempt at cochleostomy was abandoned. A repeat CT scan was performed after the first surgery with reconstructed 3D images of the temporal bone and the cochlea, and then the cochlea was successfully opened at revision surgery. Reconstructed 3D CT images were very useful to identify the site of cochleostomy in this case with such difficult temporal bone anatomy.