title: [Significance of computed tomography evaluation before revision stapes surgery].
abstract: BACKGROUND
  Stapedectomy and, more recently, stapedotomy have been widely accepted as the primary surgical techniques to improve conductive hearing in patients suffering from otosclerosis. Unsuccessful outcomes are infrequent, but revision surgery may become necessary. We have analyzed the value of computed tomography (CT) scanning following unsuccessful stapes surgery.
  
  
  METHODS
  In a total of 37 CT scans, the depth of insertion, angle between prosthesis and footplate, location of prosthesis within the oval niche, visibility of the prosthesis, dehiscence of the superior semicircular canal, and extent of otospongiotic foci were evaluated and compared with the audiometric results.
  
  
  RESULTS
  There was no significant correlation between CT parameters and audiologic results, except for patients with cochlear otosclerosis or lateral dislocation of the piston. One previously unknown dehiscence of the superior semicircular canal was diagnosed. Otospongiotic foci were seen in 13 ears (35%).
  
  
  CONCLUSIONS
  Displacements of the stapes piston and rare causes for an insufficient result, such as a dehiscence of the superior semicircular canal, can be diagnosed accurately by CT. However, correlation between the audiologic results and the findings on CT scans was possible in only a few cases. Nevertheless, CT scans provide additional information for surgical planning in revision stapes surgery and may become increasingly important to reduce unanticipated intraoperative risks; they may even guide the surgeon not to perform unnecessary revision surgeries.
authors.affiliation: Klinik für Hals-Nasen-Ohren-Heilkunde, Hals- und Gesichtschirurgie, Kantonsspital Luzern, Spitalstrasse, 6000, Luzern, Schweiz. christof.roeoesli@ksl.ch
authors.forename: C
authors.initials: C
authors.lastname: Röösli
authors.forename: A
authors.initials: A
authors.lastname: Hoffmann
authors.forename: T
authors.initials: T
authors.lastname: Treumann
authors.forename: T E
authors.initials: TE
authors.lastname: Linder
mesh_terms: D000328:Adult; D005260:Female; D034381:Hearing Loss / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D010040:Otosclerosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D011300:Preoperative Care / Q000379:methods; D013201:Stapes Surgery / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult