Cochlear orientation and dimensions of the facial recess in cochlear implantation.
OBJECTIVE
To study the dimensions of the facial recess and the spatial relationship between the facial recess and the cochlea, using CT scanning in cochlear implantees.


METHODS
In 29 cochlear implantees, preoperative CT scans of the temporal bone were compared with findings done at surgery. The dimensions of the facial recess and the relationship between the facial recess and the cochlea were both measured on a viewing station and classified on printed films by 3 blinded and independent reviewers.


RESULTS
No significant relations could be found between either intuitive classification of facial recess width or electrode array insertion feasibility and the measurements with the viewing station. The 3 reviewers had large interobserver variability. In 5 cases, neither intuitive review of the CT scans nor viewing station measurements could predict any of the problems encountered during surgery.


CONCLUSIONS
Our findings show that intuitive review was not reliable in classifying facial recess width. Viewing station measurements, in classifying the spatial relation between the facial recess and the cochlear basal turn, need a more detailed review in terms of the relationship with the operation direction and the orientation of the basal turn of the cochlea. Advanced imaging techniques, specifically multislice CT, might improve the diagnostic capabilities.
Department of Otorhinolaryngology, University Medical Center Utrecht, Utrecht, The Netherlands. RBettman@knmg.nl
Robert H R
RH
Bettman
Alex M M F
AM
Appelman
Adriaan F
AF
van Olphen
Frans W
FW
Zonneveld
Egbert H
EH
Huizing
D002814:Chorda Tympani Nerve / Q000033:anatomy & histology; D003051:Cochlea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D019929:Cochlear Implantation / Q000379:methods / Q000592:standards; D005154:Facial Nerve / Q000033:anatomy & histology; D006801:Humans; D010046:Oval Window, Ear / Q000033:anatomy & histology; D012189:Retrospective Studies; D012405:Round Window, Ear / Q000033:anatomy & histology; D013701:Temporal Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods