A true minimally invasive approach for cochlear implantation: high accuracy in cranial base navigation through flat-panel-based volume computed tomography.
OBJECTIVE
High-precision intraoperative navigation using high-resolution flat-panel volume computed tomography makes feasible the possibility of minimally invasive cochlear implant surgery, including cochleostomy. Conventional cochlear implant surgery is typically performed via mastoidectomy with facial recess to identify and avoid damage to vital anatomic landmarks. To accomplish this procedure via a minimally invasive approach--without performing mastoidectomy--in a precise fashion, image-guided technology is necessary. With such an approach, surgical time and expertise may be reduced, and hearing preservation may be improved.


METHODS
Flat-panel volume computed tomography was used to scan 4 human temporal bones. A drilling channel was planned preoperatively from the mastoid surface to the round window niche, providing a margin of safety to all functional important structures (e.g., facial nerve, chorda tympani, incus).


METHODS
Postoperatively, computed tomographic imaging and conventional surgical exploration of the drilled route to the cochlea were performed.


RESULTS
All 4 specimens showed a cochleostomy located at the scala tympani anterior inferior to the round window. The chorda tympani was damaged in 1 specimen--this was preoperatively planned as a narrow facial recess was encountered.


CONCLUSIONS
Using flat-panel volume computed tomography for image-guided surgical navigation, we were able to perform minimally invasive cochlear implant surgery defined as a narrow, single-channel mastoidotomy with cochleostomy. Although this finding is preliminary, it is technologically achievable.
Majdani
Omid
O
Department of Otolaryngology, Medical University of Hannover, Hannover, Germany. Majdani.Omid@mh-hannover.de
Bartling
Soenke H
SH
Leinung
Martin
M
Stöver
Timo
T
Lenarz
Minoo
M
Dullin
Christian
C
Lenarz
Thomas
T
D002138:Calibration; D019929:Cochlear Implantation / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008416:Mastoid / Q000000981:diagnostic imaging / Q000601:surgery; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D012016:Reference Values; D012886:Skull / Q000000981:diagnostic imaging* / Q000601:surgery; D013525:Surgical Instruments; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed