Revision Cochlear Implant

Dr Y Hui, Dr D Au

Advances in Deafness ManagementConference and Workshops

9 Oct 2005Hong 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.

Results1015202530354045505560657075808590

250 500 1000 2000 4000 Hz

So

un

d P

ress

ure

Le

vel

Initial After revision

Speech Perception (9 Adult)

Word Vowel

Consonant

Sentence

Tone

Initial (%)

66.9 74.3 82.1 86.3 60.1

Post Revision (%)

63.4 78.6 78.7 84.2 64.3

Speech Perception (7 Children) No significant difference in Ling’s 7

Sounds, vowel, consonant and sentences tests

Thank You