title: Alternative fixation of an active middle ear implant at the short incus process.
abstract: BACKGROUND
  Since 1996, the preferred approach for positioning the active middle-ear implant Vibrant Soundbridge© is a mastoidectomy and a posterior tympanotomy. With this device, placement of the floating mass transducer (FMT) on the long incus process is the standard method for treatment of mild-to-severe sensorineural hearing loss in the case of normal middle-ear anatomy. The aim of this study was to determine the vibrational effectiveness of FMT placement at the short incus process.
  
  
  METHODS
  An extended antrotomy and a posterior tympanotomy were performed in 5 fresh human temporal bones. As a control for normal middle-ear function, the tympanic membrane was stimulated acoustically and the vibration of the stapes footplate and the round-window (RW) membrane were (sequentially) measured by laser Doppler vibrometry. Vibration responses for coupling of an FMT to the long incus process (standard coupling) were compared to those for coupling to the short incus process.
  
  
  RESULTS
  Apart from narrow frequency bands near 3 and 9 kHz for the stapes footplate and RW membrane, respectively, the velocity responses presented no significant differences between standard coupling of the FMT and coupling to the short incus process.
  
  
  CONCLUSIONS
  Coupling the FMT to the short incus process may be a viable alternative in cases where the surgical approach is limited to an extended antrotomy. A reliable technique for attachment to the short incus process has yet to be developed.
authors.affiliation: Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany.
authors.forename: Sebastian P
authors.initials: SP
authors.lastname: Schraven
authors.forename: Ernst
authors.initials: E
authors.lastname: Dalhoff
authors.forename: Daniela
authors.initials: D
authors.lastname: Wildenstein
authors.forename: Rudolf
authors.initials: R
authors.lastname: Hagen
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Gummer
authors.forename: Robert
authors.initials: R
authors.lastname: Mlynski
mesh_terms: D000161:Acoustic Stimulation; D006319:Hearing Loss, Sensorineural / Q000601:surgery; D006801:Humans; D007188:Incus / Q000601:surgery*; D009998:Ossicular Prosthesis; D019933:Ossicular Replacement / Q000379:methods*; D013701:Temporal Bone / Q000601:surgery*; D014732:Vibration