title: Grading system for the selection of patients with congenital aural atresia for active middle ear implants.
abstract: BACKGROUND
  Active middle ear implants (aMEI) are being increasingly used for hearing restoration in congenital aural atresia. The existing gradings used for CT findings do not meet the requirements for these implants. Some items are expendable, whereas other important imaging factors are missing. We aimed to create a new grading system that could describe the extent of the malformation and predict the viability and challenges of implanting an aMEI.
  
  
  METHODS
  One hundred three malformed ears were evaluated using HRCT of the temporal bone. The qualitative items middle ear and mastoid pneumatization, oval window, stapes, round window, tegmen mastoideum displacement and facial nerve displacement were included. An anterior- and posterior round window corridor, oval window and stapes corridor were quantified and novelly included. They describe the size of the surgical field and the sight towards the windows.
  
  
  RESULTS
  The ears were graded on a 16-point scale (16-13 easy, 12-9 moderate, 8-5 difficult, 4-0 high risk). The strength of agreement between the calculated score and the performed implantations was good. The comparison of the new 16-point scale with the Jahrsdoerfer score showed that both were able to conclusively detect the high-risk group; however, the new 16-point scale was able to further determine which malformed ears were favorable for aMEI, which the Jahrsdoerfer score could not do.
  
  
  CONCLUSIONS
  The Active Middle Ear Implant Score for aural atresia (aMEI score) allows more precise risk stratification and decision making regarding the implantation. The use of operative corridors seems to have significantly better prognostic accuracy than the Jahrsdoerfer score.
authors.affiliation: Department of Otorhinolaryngology and Facial Plastic Operations, University Hospital Schleswig-Holstein, Ratzeburger Allee 160, 23538 Lübeck, Germany. henning.frenzel@uksh.de
authors.forename: Henning
authors.initials: H
authors.lastname: Frenzel
authors.forename: Georg
authors.initials: G
authors.lastname: Sprinzl
authors.forename: Gerlig
authors.initials: G
authors.lastname: Widmann
authors.forename: Dirk
authors.initials: D
authors.lastname: Petersen
authors.forename: Barbara
authors.initials: B
authors.lastname: Wollenberg
authors.forename: Christian
authors.initials: C
authors.lastname: Mohr
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D000013:Congenital Abnormalities / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery*; D004423:Ear / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009998:Ossicular Prosthesis / Q000706:statistics & numerical data*; D018579:Patient Selection; D015995:Prevalence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D055815:Young Adult