The ear consists of an outer, middle and inner part. Sound travels through the external ear canal in order to reach the ear drum and cause it to vibrate. This vibration is then transmitted through three small bones (ossicles) found in the middle ear. Those are called malleus, incus and stapes and form the ossicular chain. Sound then enters the inner ear where the nerve cells are. The inner ear is called the labyrinth, is snail shaped and contains fluid. The wave created in this fluid stimulates the inner ear nerve cells. Those produce nerve signals that are carried to the brain where they are interpreted as sound.
What is the mastoid bone?
The mastoid bone is the bony prominence that can be felt just behind the ear. It contains a number of air spaces the largest of which is called the antrum. It connects with the airspace in the middle ear. Therefore ear diseases in the middle ear can extend into the mastoid bone.
Why is mastoid surgery done?
Operations in the mastoid may be necessary when ear infection within the middle ear extends into the mastoid. Most commonly this is a pocket of skin growing from the outer ear into the middle ear, known as cholesteatoma. The pocket gets slowly larger, often over a period of many years, and causes gradual erosion of surrounding structures. As a result of this you can get erosion of the ossicles causing hearing loss, erosion of the labyrinth causing dizziness, erosion of the facial nerve causing facial nerve paralysis, or even erosion of the skull base causing serious brain infections.
The only effective way to get rid of this pocket of skin is surgery.
How is mastoid surgery done?
Usually a general anaesthetic is used. There are several ways of doing the operation, depending on the extent of the ear disease and the surgeon. They have various names such as atticotomy and mastoidectomy and take between one and three hours. It involves a cut either above the ear opening or behind the ear. The bone covering the infection (mastoid bone) is removed. The resultant bony defect is called a mastoid cavity which is sometimes closed up with bone, cartilage or muscle from around the ear. At the end of the operation antibiotic packing is placed in the ear while it heals.
Does it hurt?
The ear may ache a little but this can be controlled with simple painkillers.
How successful is the operation?
The chances of obtaining a dry, trouble free ear from this operation by experienced surgeons are over 80 percent. In some patients it is possible to improve the hearing as well by reconstructing the ossicles of the ear.
What are the possible complications?
Just like with any other operation there are some risks that you need to be aware of. These potential complications are nevertheless rare.
In a small number of patients the hearing may be further impaired due to damage to the inner ear or due to erosion of the disease in the middle ear.
Dizziness is common for a few hours following surgery. On rare occasions it can be prolonged.
Sometimes the patient may notice noise in the ear, in particular if the hearing loss worsens.
Weakness of the face:
The nerve that controls movement of the muscles in the face runs inside the ear. If this is damaged during the operation the face may become weak on the operated side. This is rare in experienced hands and the use of a facial nerve monitor helps.
What happens after the operation?
You will usually go home the day after the operation after the head bandage is removed. The sutures are removed 5-7 days after the operation. The packing in the ear is removed after 2 weeks. A small amount of discharge from the ear is expected and is of no concern.
The ear and the wound should remain dry for a few days after the operation to avoid possible infection.
You should take at least 2 weeks off work.