title: A true minimally invasive approach for cochlear implantation: high accuracy in cranial base navigation through flat-panel-based volume computed tomography.
abstract: 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.
authors.affiliation: Department of Otolaryngology, Medical University of Hannover, Hannover, Germany. Majdani.Omid@mh-hannover.de
authors.forename: Omid
authors.initials: O
authors.lastname: Majdani
authors.forename: Soenke H
authors.initials: SH
authors.lastname: Bartling
authors.forename: Martin
authors.initials: M
authors.lastname: Leinung
authors.forename: Timo
authors.initials: T
authors.lastname: Stöver
authors.forename: Minoo
authors.initials: M
authors.lastname: Lenarz
authors.forename: Christian
authors.initials: C
authors.lastname: Dullin
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
mesh_terms: 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