types,candidacy,surgical procedure,rehabilitation

1. Cochlear implant
DR.ROOHIA

2. Definition
• Cochlear implants are surgically placed
electrical device that receive sound and
transmit the resulting electrical signals to
electrodes implanted in the cochlea of the ear.
• The signals stimulate cochlea, allowing patient
to hear.
• It is also known as Bionic ear.

3. Parts of cochlear implant
• External
– Microphone
– Speech processor
– Transmitter
• Internal
– Receiver and stimulator
– An array of up to 22
electrodes

4. TYPES OF COCHLEAR IMPLANTS
– Advanced Bionics
– nucleus
– MED-EL

5. Advanced Bionics
• Clarion and Bionic Ear
– HiRes 90K internal
– Platinum Series Processor
– Auria BTE Processor

6. NUCLEUS
• Nucleus
– Contour and Contour
Advance internals
– SPrint processor
– ESPrit 3G BTE Processor

7. MED-EL
• Combi 40+ internal
• Tempo+ BTE processor
with 5 modular options
• CIS-PRO+ body
processor

8. Common Features of CI Sound
Processors
• Power Switch
– On-Off
• Battery
– Charge Meter
• Display
• Lights
• Program Control
– Selects Program or MAP loaded into the processor
• Individual programs may have differing parameters such as speech encoder
strategy, rate of stimulation, pulse width
• Individual programs have different electrical dynamic ranges for each electrode
which affect the perception of soft, average, and loud sounds

9. How does the cochlear implant works
Complications:

11. Cochlear Implant Surgery
• Operation lasts about three hours.(GA)
• Usually performed as outpatient
• Performed by Otolaryngologist

12. CANDIDACY PROFILE FOR COCHLEAR
IMPLANTS
• B/L severe to profound SNHL
• Little or no benefit from hearing aids
• No medical contrindication for surgey
• Realistic expectation
• Good family &social support towards
habilitation
• Adequate cognitive function to be able to use
the device.

13. Pre-implantation Process
• Medical Evaluation. ENT examines the outer,
middle and inner ear (otological examination)
• Physical examination
• Imagery Evaluation: x-ray, CT scans, MRI
• Audiological evaluation: Audiologist tests
hearing.
 PTA
 Speech discrimination
 Tympanometry
 OAE
 ABR
 Auditory steady state response(ASSR)
• Speech and Language Testing

15. SURGICAL TECHNIQUE
• Facial recess approach
• Pericanal techniques
eg;suprameatal approach

18. Step 1 - Flap marking and incision design

19. • After the skin/subcutaneous tissue flap has
been elevated, a separate anteriorly based
pericranial flap is then elevated
• The subcutaneous pericranial flap should be
2 to 3 cm in the cephalocaudal dimension
and at least 2 cm in length

20. Step 2 - Mastoidectomy and posterior tympanotomy

21. • The mastoidectomy cavity should not be
• saucerized. The edges should be left as acute
as possible.
• These edges will help retain the electrode
leads
• within the confines of the mastoid cavity

22. Step 3 - Cochlear implant receiver well drill out with
tie-down holes

23. • Using a mock-up of the transducer for sizing,
a well is drilled into the outer cortex of the
parietal bone to accept the transducer
magnet housing
• Small holes are drilled at the periphery of the
well to allow stay sutures to pass through.
• These suture will be used to secure down the
implant
• Stay sutures are then passed through the
holes

25. Step 4 - Cochleostomy
• Using the incus as a depth level, the facial
recess is then drilled out
• Through the facial recess, the round window
niche should be visualized
• Using a 1 mm diamond burr, a cochleostomy
is made just anterior to the round window
niche
• varies from 1.0 to 1.4 mm. The endosteum
may be opened with a 25-gauge spinal
needle, straight pick, or Beaver 59-10 cataract

27. Step 5 - Implant tie down and electrode
insertion
• The pocket for the receiver
stimulator is copiously
irrigated with dilute
bacitracin solution,
• any final hemostasis
necessary is undertaken.
Monopolar
electrocoagulation systems
are turned off and
unplugged.
• The transducer is then laid
into the well and secured
with the stay sutures

28. • Hyaluronic acid or 50%
glycerine may be used to
keep blood out of the
scala during electrode
insertion and to lubricate
the electrode
• The electrode array is
then inserted into the
cochleostomy and the
accompanying guidewire
is removed

29. • Small pieces of harvested periosteum are
packed in the cochleostomy around the
electrode array, sealing the hole
• Fibrin glue is then used to help secure the
electrode array in place
• The wound is then closed in layered fashion
and a standard mastoid dressing is applied

30. • Goals of Surgery:
• The surgical technique used for cochlear
implants aims to:
• Insert the electrode array without causing
damage to the scala tympani
• Place the implant package against the side of
the head so it is less prone to external trauma

31. • To secure both the electrode array and the
implant package to prevent migration after
surgery
• To implant all the internal components
without damaging the tympanic membrane,
ear canal, facial nerve, scalp or any other
surrounding tissue

32. COMPLICATIONS
• (1) Scalp Flap Problems – can include infection,
necrosis and thickness. Infections require
immediate treatment with antibiotics.. In this
case, thick flaps have to be carefully thinned by a
surgeon.
• (2) Otitis Media – is an infection of the middle
ear, administration of antibiotics and sometimes
pain reliever.
• (3) Meningitis –. This is a rare postoperative
complication but has the potential to be serious.
Cerebrospinal fluid (CSF) may leak and cause

33. • 4) Facial nerve paralysis – Electromyographic
monitoring of the facial during the surgery can
help reduce the possibility of paralysis.
• (5) Tinnitus –. Tinnitus may be the result of
further damage to existing hair cells.
• (6) Vertigo – or dizziness may be caused by
labyrinthitis, inflammation of the part of the
ear responsible for balance, and is a larger
issue for the elderly who have more difficulty
compensating.

34. • 7) Device migration – is a rare complication. If
the implant package is not secured it may create
shear forces that can break the electrode.
• (8) Device failure – can result from
manufacturing defects or from trauma. Delayed
device failure occurs in about 1.5% of implants
and need to be replaced.Tests during the
operation procedure can avoid implanting a
defective device.
• (9) Facial nerve stimulation – occurs when
stimulation to the electrode is conducted through
bone and also stimulates the facial nerve. This
type of complication is fixed by changing the

35. Activation and Initial Fitting
• An audiologist fits the patient with:
– A microphone (resembles
a BTE hearing aid)
– A speech processor (may be
housed with the microphone or
worn at chest-level)

36. Activation and Initial Fitting
• Audiologist runs standard check
of the speech processor
• Initial activation and programming
(mapping) of the implant
– Mapping- a set of parameters of electrode stimulation that gives the
patient maximum hearing
– Establishment of electrical dynamic range
– May occur over several appointments because the
patient will adjust to sound as s/he gains
experience with the implant

37. • How is mapping conducted?
• Using speech (subjective)
• Using tones/beeps/bursts
(subjective)
• Neural Response Telemetry (objective)
– Telemetry is the remote measurement of various electrical
parameters (in our case, through implant feedback)
– Neural Response Telemetry measures the response of the
auditory nerve to electrical stimulation via a cochlear implant
(The Hearing House).
– NRT takes about 5 minutes to complete

38. Follow-Up to Initial Fitting
• May include several visits over the span of weeks or months
• Why is this such a lengthy process?
– Each electrode in the cochlea is activated
– Each electrode must be programmed and adjusted into the
speech processor
– Can create programs for special listening situations
– The patient develops more skill from using the implant, thus
more adjustments must be made as skill improves
– Over time, less adjustments are necessary and the patient will
return to the CI center every 6 months or annually
– Appointment time can be spent on education and rehabilitation

39. Aural Rehabilitation
Teaches the patient how to use the CI and respond
to auditory input
– Listen to an array of auditory stimuli
– Improve speech (expressive and receptive)
– Use speech-reading

40. Complications:
• Early complications
• (1) Scalp Flap Problems
• (2) Meningitis
• (3) Facial nerve paralysis
• (4) Tinnitus
• (5) Vertigo
• (6) Device migration
• (7) Device failure
• (8) Facial nerve
stimulation
• Late complications
• 1)exposure of device
&extrusion
• 2)pain at the site of
implant
• 3)migration/displacement
of device
• 5)late device failure
• 6)otitis media

41. COCHLEAR IMPLANT FAILURE
• Hard Failures occur when the device fails to deliver any stimulation to the
cochlea
– Stimulator fails
– Speech processor fails to establish link with implanted system
– no auditory input to patient
• Soft Failures occur when the speech processor maintains a lock with the internal
system but fails to deliver proper stimulation
– Auditory symptoms - subjective decrease in performance, lack of sound perception, severe
tinnitus, sound hypersensitivity, atypical tinnitus (thumping, engine like noise, airplane sounds,
clicks, pops, sirens)
– Non auditory symptoms – pain, shocking sensations, vertigo, facial twitching
– Performance-related issues
• Medcal complications (asom/csom)
• Skin infection
• Device misplacement
• Electrode extrusion

42. Implant Failure Diagnosis
• Initial testing
– Patient’s history
– Recent changes in MAP (patient’s individualized fitting program)
– Reprogramming MAP if necessary
– Check external components - cables
• Impedance testing of electrode using clinical software
• EFI(Electrical field imaging)
• Link Test
– Integrity of linkage between the inside and outside of device
– Determine if there is sufficient energy to power device at all instances

43. THANK YOU