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SURGICAL TREATMENT OF MENIERE\'S DISEASE: NON-DESTRUCTIVE AND DESTRUCTIVE SURGERY
When Meniere\'s disease is not controlled by a combination of medical measures, surgery may be necessary. Fortunately, this is required in only a small percentage of sufferers. Procedures are of two types:
- those that aim to alter the course of the disease and
- those that destroy the balance mechanism in order to gain control of the vertigo.
Non-destructive surgery
The endolymph fluid of the inner ear is thought to be absorbed or removed by an extension of the inner ear mechanism which sits in the mastoid bone (which forms part of the skull behind the ear). This structure in the mastoid is called the endolymphatic sac.
Operations on the endolymphatic sac may improve or alter its function and help control Meniere\'s disease. The sac is decompressed and the fluid may be shunted in to the mastoid. The blood supply and the biochemical function of the sac may be changed. These procedures are aimed at altering the course of the disease without any loss of function. Vertigo, tinnitus and pressure can be improved and hearing stabilized. Unfortunately, these operations are successful only in approximately half to two thirds of the patients on whom they are performed.
Destructive surgery
When vertigo is uncontrolled, destruction of the balance mechanism of the affected ear or disconnection of that mechanism from the brain may be necessary. This is generally after all other measures have been employed and have failed.
If there is still useful hearing in the ear, it is possible to cut the nerve that connects the balance mechanism to the brain and leave the hearing nerve intact. This is called vestibular nerve section or vestibular neurectomy, and requires an approach that spares the inner ear. This is usually achieved by operating behind the inner ear and even behind the mastoid.
When there is no useful hearing and surgical control of vertigo is necessary, an approach through the inner ear can be used. Partial destruction may be enough and chemical ablation with direct injection of drugs in to the inner ear can be useful.
Surgical destruction of the inner ear or labyrinthectomy can give very good control of the troublesome vertigo. The vestibular nerve can also be sectioned through the same approach, to give complete ablation of balance function in the affected ear and the best chance of control of vertigo.
*9/133/5*
GENERAL HEALTH
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