A craniotomy is an operation that involves opening the skull to remove the brain tumour. The surgeon cuts a piece of the skull, which is later replaced, to reach the tumour. They use a powerful microscope and special instruments to remove all or as much as possible of the tumour without taking healthy tissue.

Sometimes they may use keyhole surgery to remove a tumour through a very small opening in the skull. They pass a thin flexible tube with special instruments attached to it through the opening and remove the tumour.

To reduce the risks of surgery some people have a craniotomy while they’re awake. It means the surgeon can check during surgery that your speech or movement isn’t being affected. This sounds frightening but you can talk to the doctors and nurses during it and most people cope well with it. You have a sedative to help to relax you and they numb the area of your scalp with local anaesthetic.

Before surgery your surgeon will explain what will happen and what to expect.

What happens during a craniotomy?

To remove the tumour, you will need an operation called a craniotomy. In a craniotomy, the neurosurgeon removes an area of bone from the skull to get to the brain tissue underneath.

They cut the scalp and a piece of the skull over the tumour. After removing part or all of the tumour, they replace the piece of skull and use stitches or staples to close the scalp.

You will usually have a general anaesthetic. Before the operation starts, they may shave an area of your hair off. You will be under anaesthetic at this point so won’t be aware of this. If you’re

worried about this, you can talk to your nurse or doctor before the operation.

The surgeon uses specialised instruments and a powerful microscope to look at the brain tissue. This means they can remove the tumour without taking healthy tissue.

Sometimes the surgeon uses keyhole surgery which is done through a small opening in the skull rather than a larger opening. They use an instrument called a neuroendoscope.

This is a thin, flexible tube with a camera on the end and an eyepiece to look through. The surgeon attaches special instruments to the neuroedoscope to remove the tumour.

They will explain if this is suitable in your situation. If it isn’t possible to remove the whole tumour, the surgeon will remove as much of it as they can. This is sometimes called a partial resection or debulking.

After the operation, all the tissue the surgeon removed is sent to a laboratory to be examined by a pathologist.

Having a craniotomy when you're awake

Some people have a craniotomy while they are awake. This may sound frightening but people usually cope well with it. The aim is to reduce the risks of surgery. Because you’re awake, the surgeon can do checks to make sure functions such as speech or movement aren’t being affected. If anything changes, they can stop operating. Your surgeon and nurse will explain what will happen so you know what to expect.

Before the operation, they will give you a sedative to help you relax. You will also have local anaesthetic injected into the area where they make the incision (cut) to make it numb. You can see and talk to the doctors and nurses during the operation.

Back to Surgery explained

When is surgery used?

Surgery can be used to remove all or part of the tumour or to give chemotherapy into the brain.


A biopsy consists in removing and examining a small piece of tissue. It’s used to identify the tumour’s type.


A shunt is a thin tube that drains extra fluid away from the brain to relieve raised intracranial pressure.

What happens before surgery?

To prepare for your operation, you’ll have some tests and may be given steroids. If you smoke, try to give up or cut down.

Who might I meet?

A team of specialists will plan your surgery. This will include a surgeon who specialises in your type of cancer.

What happens after surgery?

You'll be monitored closely after your operation. You may have a drip (infusion) giving you fluids for a short while.