Skull Base Surgery

Procedures & Operations

The Skull Base is that area of the head which separates the brain above from the eyes, mouth, nose, and hearing associated structures below. The most common disorders involving the skull base are tumours. Such skull base tumours, involving the skull base, may be histologically ‘benign’ (e.g. meningiomas, acoustic neuromas, or pituitary adenomas) or cancers (e.g. arising in paranasal sinuses, ear canal, or salivary glands). All can have very serious consequences for an individual and require management from a multidisciplinary team, including ENT experts.

Not all tumours of the skull base require surgery but when surgery is required it is usually performed by a team comprising an ENT surgeon and a neurosurgeon. Sometimes other surgeons are also involved. This might include a plastic surgeon, maxillofacial surgeon or ophthalmic surgeon.
The type of surgery performed depends on the site, type and size of the tumour as well as the expertise of the team.

Broadly speaking procedures are divided according to whether the tumour is involving the front part of the skull base (anterior cranial fossa) or the middle part of the skull base (middle cranial fossa).

Anterior Cranial Fossa Operations

Endoscopic Sinus Surgery
This type of surgery is usually performed for the removal of tumours involving the nasal cavity. Sometimes tumours with limited involvement of the skull base can also be removed using this type of surgery.

The operation is performed using special telescopes (also called endoscopes) through the nostrils. This means there are no scars and the stay in hospital is usually short.

Craniofacial Resection
For larger tumours that have affected the anterior skull base, it is sometimes necessary to remove a larger portion of the bone around the skull base to ensure that the tumour is completely removed. This requires a cut either just above the eyebrows or in the hairline over the top of the head.

Middle Cranial Fossa Operations
There are three main operations performed to remove tumours involving the middle or back portion of the skull base.

Translabyrinthine Approach
This is the most commonly performed operation and is used mainly for the removal of acoustic neuromas. It requires removal of most of the bone around the ear and as a result the hearing is lost on this side. However, the majority of patients having this sort of surgery have poor hearing already. By removing the bone, the lining of the brain is exposed and can be opened with minimal brain retraction in order to enable removal of the tumour.

Retrosigmoid Approach
This approach can be used to remove tumours instead of the translabyrinthine approach. It involves cutting a bony window in the skull behind the ear. This technique is useful in patients with small to medium sized tumours and good hearing as it sometimes allows preservation of hearing.

Middle Fossa Approach
This approach involves cutting a window in the bone of the skull immediately above the ear. It can be used to remove small tumours in patients with good hearing as it sometimes allows preservation of hearing.