Revision Cochlear Implant by mikeholy

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									Revision Cochlear Implant


         Dr Y Hui, Dr D Au

  Advances in Deafness Management
     Conference and Workshops
             9 Oct 2005
             Hong Kong
Experience from QMH
 1989 – 2005
 18 patients required surgery for revision
 Children (<12)      -9
 Teenager (13-19) - 4
 Adult (>20)          -5

 Time interval: 5m to 7yrs (mean 4 yrs)
Reason (n=18)
 Primary Device failure   15
 Electrode extrusion      1
 Infection                1
 Trauma                    1
Presentation
 Sudden deterioration in hearing
 Often preceded by periods of
 malfunction

 Audiologist called for immediate
 assessment.
ENT assessment
 Otoscopy
 Implant site
 Plain XR
Confirm the Dx
 Audiologist from the manufacturer to
 confirm the diagnosis
What are the issues
1.   Financial cost (currently a 10 year
     warranty)
2.   The need for another surgery
     (approach Avoidance conflict)
3.   Intervening period of deafness – affect
     work/school
4.   Will the new implant fail soon?
Approach
 Diagnosis convey to patient
 Revision Surgery ASAP or at a time
 convenient to patient.
Surgery
Audiologist from manufacturer

Old incision
New bone over the electrode &/or the
receiver
No new bone over the posterior
tympanotomy
No post-op complication
Infection with Staph
Epidermidis
Revision as a result of trauma
Revision as a result of trauma
Post-op mapping
 Easier to perform
 Prior experience with mapping
 Eager to make to sure the new implant
 is functioning well
 If this is an upgraded model, they want
 to find out the difference.
Discussion
 We tell the patient of such possibility
 before the operation
 Some patients anticipate this as an
 inevitable event in the future.
 See this as an opportunity to upgrade
Discussion
 Revision surgery may become more
 common
 Primary failure may reduce
 Voluntary decision to replace old model
 with a more advance one.
Results
                             250   500             1000       2000     4000   Hz
                        10
                        15
                        20
                        25
                        30
 Sound Pressure Level




                        35
                        40
                        45
                        50
                        55
                        60
                        65
                        70
                        75
                        80
                        85
                        90


                                         Initial      After revision
Speech Perception (9 Adult)
           Word Vowel Consonant Sentence Tone



Initial (%) 66.9   74.3   82.1    86.3   60.1



Post       63.4    78.6   78.7    84.2   64.3
Revision
(%)
Speech Perception (7 Children)
 No significant difference in Ling’s 7
 Sounds, vowel, consonant and
 sentences tests
Thank You

								
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