If the tumour is blocking the flow of cerebrospinal fluid (CSF) around the brain, pressure can build up and cause symptoms. The surgeon can drain away the extra fluid by putting in a long, thin tube called a shunt.

The surgeon makes a small hole in the skull behind your ear and places one end of the tube (shunt) into the brain. They thread the tube under the skin to another part of the body. This is usually to a space in your tummy called the peritoneal space. The extra cerebrospinal fluid drains into this area and is re-absorbed by the body.

The tube has a valve that controls the amount of CSF that drains through it. It only allows fluid to drain away from the brain and not back towards it.

You cannot see the tube from outside of the body but you may be able to feel it under the skin behind your ear.

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.

Having your operation

A team of healthcare professionals will help you before and after surgery for a brain tumour.

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.