(BAHA AND MIDDLE EAR IMPLANT)

Implanted and Semi-implanted Hearing Aid

Bone Anchored Hearing Aids (BAHA)

What is BAHA?

BAHA is surgically implantable system for treatment of hearing loss that works through direct bone conduction.

BAHA consists of three parts: a titanium implant, an external abutment, and a sound processor.

The sound processor transmits sound vibrations through the external abutment to the titanium implant .

BAHA

Candidacy :

CHL and Mixed HLSingle sided deafness (profound unilateral

SNHL)

Indications:

Chronic otitis mediaAtresia/ Microtia

Acoustic neuroma Cholesteotoma

Menier’s diseaseOtosclerosis

External otisisTrauma

Sudden deafnessOtotoxic drug exposure

Contraindications for the surgery

Children can’t be implanted until 3 years oldComplication include inflammation and

infection of skin surrounding abutmentPresent of foreign object makes it more

difficult for body to fight infectionCrusting around site cause decreased

comfort and sound quality Overgrowth of skin over abutment site may

require surgical removal

BAHA Technology

Head-worn BAHA (most common): microphone, amplifier, and vibrator are contained within a single package.

Package snaps onto an abutment that is screwed into the titanium screw fixture. This direct connection to the skull is called Percutaneous coupling.

Body-worn BAHA: more powerful than head-worn. Only the transducer is mounted on the head. The microphone and amplifier are housed in a slim case worn on body.

BAHA maintenance (when NOT to wear your BAHA)

Remove BAHA before bedRemove BAHA in shower/rain

Remove BAHA during contact sportsRemove BAHA when getting a haircut

Remove BAHA when applying a hair gel or hair spray

BAHA maintenance (Daily BAHA cleaning routine)

Both the abutment and the surrounding skin must be thoroughly cleaned as a part of a daily hygiene routine

Wash the abutment area with warm water everyday

After area is clean, use a cotton swab or a soft cleaning brush to clean gently around and inside the abutment

The Advantages of BAHA

The BAHA transmits sound very directly as it is in direct contact with the bone. This results in improved sound quality for individual who have been shown to benefit from a bone conduction hearing aid.

As the bone conduction thresholds for these patients are better than the air conduction equivalents, less amplification is needed by the BAHA compared to a conventional air conduction hearing aid to overcome the hearing loss. This may then make sound more natural with less distortion thus benefiting speech discrimination.

 The comfort of the BAHA is a great improvement compared

to conventional aiding as there is nothing in the ear to aggravate ear infections or irritations, nor is there any pressure exerted on the skull causing discomfort and headaches.

 The sound is constant and does not vary depending upon either the

state of the ear as may occur with air conduction hearing aids in an infected ear, or the position/movement of the transducer with a conventional bone conduction hearing aid 

The sound processor is clipped onto the abutment making it feel weightless and therefore very comfortable to wear compared to bone conduction headbands.

 For individual who have problems with discharging ears there is no

ear mould. This keeps the ear clear and helps to prevent infection, humidity build up and skin irritation.

 As there is no headband, Cosmetically many people prefer the BAHA

to their bone conduction hearing aid. 

For individual with absent or malformed external ears conventional hearing aids can be very difficult to fit well.

  

The Disadvantages of BAHA

Surgery is involved and therefore risk factors for general anaesthetics need to be considered. Most individual will have a two-stage surgical procedure and therefore two general anaesthetics.

There is a risk of surgical complications, such as infection.

The abutment area needs to be kept clean, which requires a regular commitment from another person.

There is a risk that head trauma, e.g. a blow to the implant site (with or without the presence of the processor), may have more serious consequences than might occur with a conventional hearing aid and precautions need to be considered, such as head protection for sports.

The procedure may not be available locally

Middle Ear Implant

What is a Middle Ear Implant?

A middle ear implant is a medical prosthesis that is implanted in the middle ear and mechanically vibrates the middle ear structures.

Also known as Vibrant Sound Bridge (VSB)

Middle ear implant users  

Middle ear implants are primarily used by people who do not benefit from or are unable to use traditional hearing aids, such as:

People with an obstruction of the outer or middle ear

People who cannot wear hearing aids or ear moulds

People who are unable to benefit from sound amplification

Many people with sensorineural hearing loss can benefit from using middle ear implants .

Candidacy criteria & fitting range:

1-SensoriNeural Hearing Loss: AC Thresholds within shaded area .

Normal ME function. SRT at least 50% at 65dB SPL in a free-field using hearing aid. Stable hearing loss. Patient should be experienced with hearing aids.

2-CHL + Mixed Hearing Loss: BC Thresholds within shaded region.

Ear anatomy allows for positioning of the FMT. No active middle ear infection/ chronic fluid. Stable BC Thresholds

The most obvious difference between middle ear implants and other hearing aids is that no speaker is necessary .

-Unlike a hearing aid which only makes sounds louder, the VSB converts sounds from the environment into mechanical vibrations.

-The technology of the VSB bypasses the outer ear in order to directly stimulate middle ear structures for exceptional high frequency sound perception

Middle ear implant

Middle ear implant component

External Part :Amadé  (The Compact Audio Processor)With the Amadé audio processor, the Vibrant Soundbridge features outstanding signal processing technology. The audio processor is held directly over the implant by magnet, allowing it to be comfortably and discreetly worn beneath the hair.

Internal Part :VORP and FMT Implant.The implantable component of the Vibrant Soundbridge consists of the Vibrating Ossicular Prosthesis (VORP) and the Floating Mass Transducer (FMT). The signal sent by the audio processor is processed by the VORP and converted by the FMT into mechanical vibrations that are transmitted directly to the middle ear structures.

How Middle ear implant works:

Sounds are picked up by the microphone of the audioprocessor. The audio processor converts environmental sounds intoelectrical signals. The electrical signals are transmitted across the skin tothe implanted part. The implant relays the signal down to the FMT The FMT converts the signal into mechanical vibrationsthat directly stimulate a middle ear structure causing itto vibrate. These vibrations then conduct sound to the inner earwhere they are passed on to the brain and are perceivedas sound.

What are the outcomes of the Middle Ear Implant?

A middle ear implant does not restore normal hearing and requires time to acclimatize to the sound quality. The degree of benefit varies with each individual. Variables influencing the benefits each person will derive include factors such as age, degree and duration of hearing loss and integrity of the auditory system .

What is the patient management pathway?

The expected length of assessment from referral to the final consent appointment is typically 18 weeks, although the assessment may be extended for many reasons, including patient request or medical reasons. Following the assessment the patient will either be listed for surgery or discharged from the clinic. The results of tests will be explained as the assessment progresses. On completion of the assessment a team report will be sent to the referrer as well as the other professionals you have asked us to inform.

The initial meeting with Audiological Scientist who will:

Explain the assessment processTake a detailed case history.

Discuss the middle ear implant and issues surrounding implantation, expectations and potential outcomes.

Conduct some audiological testing

Initial Screening Appointment

If the patient is suitable to continue then s/he will undergo a full assessment:

Further Audiological Assessments Further clinic appointments will be issued to assess your

hearing, amplification needs, and functional aided hearing abilities. The number of appointments required will vary but will typically include the following.

Hearing Aid Fitting - to optimize your hearing aid settingAuditory Brainstem Response Test – an objective, non-

invasive hearing test Speech Perception tests

Pre-operative Questionnaires

Each patient’s management plan is discussed and reviewed at the monthly multi-disciplinary team meeting.

The meeting with the ENT surgeon will involve discussion regarding:

Medical historyDecisions made regarding further

assessments required.Magnetic Resonance Imaging (MRI) and

possibly Computer Tomography (CT) may be discussed and booked to check the integrity of the cochleae and hearing nerves .

Medical Assessment

The final appointment with the surgeon will involve discussion of:

Medical issues surrounding the middle ear implant surgery

Surgical risks and side effects (temporary taste disturbance, tinnitus, dizziness, balance impairment, infection, device failure, etc.)

Surgical consentOnce consent is signed the patient will be

offered an operation slot within 8 weeks. The device will then be activated about 8 weeks after surgery .

Final ENT Consultation

The Advantages of middle ear implant

There is less feedback and whistling with these devices, allowing greater amplification.

They do not block the ear canal so patients get less echoing of their own voice.

Because the ear canal is not blocked, it is less likely to become sweaty, moist and infected    .

It is claimed that sounds seem clearer and more natural than with a conventional hearing aid .

They are more comfortable, and of course the cosmetic appearance is also a factor.

The disadvantages of middle ear implant

The cost of implanting these devices is undoubtedly greater than the cost of a hearing aid.

MRI scanning of the head and neck is contra-indicated with the implant in situ.

There are always risks associated with surgery, including anaesthetic risks and specific risks associated with middle ear surgery.

There is concern about potential long term damage to the ossicles or hearing, as constant movement against the ossicles may cause erosion of the ossicles, and non-physiological stimulation may cause inner ear damage. These devices have only been used for the last 5 years so long term data is not available, but the information available so far suggests that this not a significant problem.

Thank you

Group2Alhanouf AlfadhlFarah AlthobianiHaifa Bin Omair

Hala AlotaibiMunera Alqahtani

Sara AlKhamis

References:

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ants:// . . / / / / /http www hearingloss org sites default files docs Dillo

_ _ .n Adunka saturday pdf:// . - . / - -http www hear it org Middle ear implants

:// . . / / / / /http www cochlear com wps wcm connect au ho:// . . / / - / /http www medel com in vibrant soundbridge me disco

/ - - -ver baha bone conductionimplants

:// . . / /http entdoctor org uk html _ .auditory implants htmlhttp://www.google.com.sa/url?

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