Why is BAHA surgery carried out?

A BAHA, or Bone-anchored hearing aid, is a special sort of hearing aid in which sound is transmitted directly through the bone to the inner ear (cochlear), bypassing the ear canal, ear drum and bones of hearing (ossicles).

It tends to be used for patients who can't wear normal hearing aids because of problems with mastoid cavities, repeated infections, or ear canal scarring or narrowing.

BAHA's are also sometimes used to help people with complete hearing loss in one ear. In this situation they work by transmitting sound from the deaf side to the hearing side, using the bone of the skull to conduct the sound.

In order to wear a BAHA it is necessary to insert a small titanium screw (much like the sort now being used for tooth implants) into the bone just above and behind the ear. This screw becomes very firmly attached to the bone through a process called osseointegration. It is also sometimes necessary to thin down the skin around the screw to allow the BAHA to be fitted and removed properly.

There is a small post (abutment) which is permanently attached, but the hearing aid itself clips on and off.

Are there any alternatives to surgery?

All patients who are considering BAHA surgery will have a full assessment by one of our specialist audiologists. Any other hearing aid options that may be suitable for you will be discussed at this appointment.

How is the surgery performed?

The operation can be carried out under either a general (completely asleep) or local (with the area numbed) anaesthetic. Most of our patients prefer a general anaesthetic, as it can sometimes be uncomfortable staying still for the 30 -45 minutes  that the operation takes, and the drilling required to insert the screw can seem be very noisy.

The screw is inserted into the bone, attached to the post or "abutment" that the hearing aid fits on.

The abutment is permanently attached (although it can occaionally need changing).

Depending on various factors including the thickness of the scalp, it may rarely be necessary to thin down the skin around the abutment. However normally the abutment is long enough to stand clear of the scalp tissues and allow the BAHA to be attached easily.

The would is then closed with stitches and dressings and a "healing cap" (a small disc of plastic used to hold the dressings in place) are applied.

What can I expect after the surgery?

You may have a bandage around your head when you wake up. This is to reduce the chances of bleeding or extensive bruising. This will be removed after 6 hours and you will then be allowed home, on the same day as your surgery.

You will then have outpatient appointments 1,2 and 6 weeks after the operation. You will see one of our specialist nurses as well as one of the surgical team. At the first appointment you will have your dressings changed or removed.  Your stitches will be removed at the second appointment and the 6 week appointment is for a final check that all has healed.

The hearing aid will then be fitted three months after the operation, once the screw has had a chance to become properly attached to the bone.

What are the risks of the surgery?

All operations, however carefully and expertly they are carried out, have risks attached.

Whilst we always do our best to operate only when we think there is a good chance of the surgery being successful, there is always a chance that the hearing with the BAHA will not be as good as we had anticipated.

As with almost any operation there is a small risk of post-operative infection, bleeding or bruising.

You may well notice some numbness of the scalp around or above the BAHA, particularly if we have had to use a skin graft. This generally settles down with time, but may take a few months to settle completely. Occasionally there is some discomfort or pain associated with this numbness.

There is a small chance that the graft will not "take" properly, resulting in delayed healing.

The screw generally bonds very firmly with the bone, but there is a very small chance of this not happening properly and of the screw becoming loose or falling out. This is particularly a risk if the BAHA is knocked or banged in the first few weeks after the operation.

If we do have to thin the skin down with a graft there is a chance that with time the skin will thicken up again. Normally this isn't too much of a problem but occasionally it can cause problems with wearing the BAHA. If this happens it may be necessary to thin the skin back down, which is generally a fairly minor procedure that can be carried out under local anaesthetic (with the area numbed).