If the tumour is blocking the flow of cerebrospinal fluid (CSF) around the brain, pressure can build up inside the brain. The surgeon treats this by putting in a shunt to drain away the extra fluid.

They may also use a small device called an ommaya reservoir.

A shunt is a long, thin tube. It’s placed into the brain and threaded under the skin to another part of the body, usually the lining of the tummy (called the peritoneum). The extra fluid drains into this area and the body reabsorbs it. The shunt has valves in place so fluid can drain away from the brain but not back towards it. It can’t be seen from outside of the body and you won’t be able to feel it.

These treatments to relieve pressure are usually in clinical trials.

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.


The surgeon removes all or as much as possible of the brain tumour with an operation called a craniotomy.

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.