title: Revision surgery due to magnet dislocation in cochlear implant patients: an emerging complication.
abstract: OBJECTIVE
  To analyze the cause and effect of magnet dislocation in cochlear implant (CI) recipients requiring magnet revision surgery for treatment.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Case reports from 1,706 CI recipients consecutively implanted from January 2000 to December 2011 were reviewed. The number of cases requiring magnet revision surgery was assessed.
  
  
  RESULTS
  Revision surgery involving magnet removal or replacement was indicated in 1.23% (21/1,706), of all CI recipients. Magnet dislocation occurring during magnetic resonance tomography (MRI), at 1.5 Tesla (T), with the magnet in place and with the application of compression bandaging around the head, was the main cause for revision surgery in 47.62% (10/21) of the affected cases. All 10 cases were implanted with Cochlear Nucleus cochlear implants. These events occurred, despite adherence to current recommendations of the manufacturer.
  
  
  CONCLUSIONS
  The present study underlines that MRI examination is the main cause of magnet dislocation. The use of compressive bandaging when using 1.5-T MRI does not eliminate the risk of magnet dislocation. Additional cautionary measures are for required for conditional MRI. We recommend X-ray examination after MRI to determine magnet dislocation and avoid major complications in all cases reporting pain during or after MRI. Additional research regarding silicon magnet pocket design for added retention is needed. Effective communication of guidelines for precautionary measures during MRI examination in CI patients is mandatory for all clinicians involved. MRI in CI recipients should be indicated with caution.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Frederike
authors.initials: F
authors.lastname: Hassepass
authors.forename: Vanessa
authors.initials: V
authors.lastname: Stabenau
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Maier
authors.forename: Susan
authors.initials: S
authors.lastname: Arndt
authors.forename: Roland
authors.initials: R
authors.lastname: Laszig
authors.forename: Rainer
authors.initials: R
authors.lastname: Beck
authors.forename: Antje
authors.initials: A
authors.lastname: Aschendorff
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D003054:Cochlear Implants; D004868:Equipment Failure; D005260:Female; D006801:Humans; D059346:Magnets; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies