title: [Intracochlear electrode position: evaluation after deep insertion using cone beam computed tomography].
abstract: BACKGROUND
  Due to the increasing number of cochlear implantations (CI), postoperative radiological verification of the electrode position, e.g., with respect to quality control, plays a central role. The aim of this study was to evaluate the intracochlear position of deep inserted electrodes by cone beam computed tomography (CBCT).
  
  
  METHODS
  CBCT data sets (Accu-I-tomo, Morita, Kyoto, Japan) of 22 patients (28 ears operated between 2008 and 2011) were retrospectively analyzed. All patients underwent a CI (round window approach) with deep insertion of the electrode (Flex soft or standard electrode from MedEl©). CBCT data were analyzed for intracochlear position of the electrode (scala vestibuli, scala tympani, malposition between the scalae) and the certainty of this evaluation.
  
  
  RESULTS
  All ears could be evaluated with the status certain or relatively certain in the basal turn of the cochlea. Thereby, the electrode array was inserted into the scala tympani in 93% (n = 26). Primary insertion into the scala vestibuli and the scala media was observed in 3.5% of the ears, respectively. In the apical part of the cochlea, only 32% (n = 9 ears) could be evaluated with relative certainty. The remaining 68% of cases could not be evaluated. Of the 32% interpretable cases in the apical part of the cochlea, 25% (n = 7) were inserted into the scala tympani, 3.5% (n = 1) into the scala vestibuli, and 3.5% (n = 1) were malpositioned between the scalae.
  
  
  CONCLUSIONS
  The exact evaluation of the intracochlear position of the electrode by CBCT is only possible in the basal turn of the cochlea. In deep insertion, determination of the position in the medial and apical parts of the cochlea by CBCT is still not possible. Furthermore, the round window approach allows reliable implantation into the scala tympani.
authors: Univ.-Klinik für HNO-Heilkunde, Kopf- und Halschirurgie, UKGM, Marburg, Deutschland. gueldner@staff.uni-marburg.de
authors: C
authors: C
authors: Güldner
authors: R
authors: R
authors: Weiss
authors: B
authors: B
authors: Eivazi
authors: S
authors: S
authors: Bien
authors: J A
authors: JA
authors: Werner
authors: I
authors: I
authors: Diogo
mesh_terms: D003051:Cochlea / Q000000981:diagnostic imaging* / Q000601:surgery*; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome