Cochlear implants are surgically implanted devices that provide a sense of sound to those who are profoundly deaf or severely hard of hearing. They consist of internal and external parts. The internal parts include a receiver and electrodes that are surgically placed inside the cochlea. The external parts include a microphone, speech processor, and transmitter. Sound is picked up by the microphone, processed by the speech processor, and transmitted to the internal receiver which sends electrical signals to the electrodes, bypassing damaged hair cells to stimulate the auditory nerve. Candidates undergo testing, surgery, activation and mapping sessions, and rehabilitation to learn to understand speech with their implant. Potential complications include infection, device failure or migration that may require reoperation.

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