What is a shunt for the brain?

A shunt is a hollow tube that is surgically inserted into the brain. It is used to drain cerebrospinal fluid from the brain and send it to other parts of the body. This can help relieve pressure in your skull, which might lessen symptoms like headaches, sickness, and blurred vision.

Headaches are a common symptom of brain tumours, often caused by a build-up of the cerebrospinal fluid (CSF) in the brain. CSF usually circulates within the skull, but a tumour can block this and cause a build-up, known as ‘hydrocephalus’. This causes the pressure inside the skull to rise, which can lead to headaches, blurred vision and sickness.

If this happens a neurosurgeon may recommend that they operate to insert a tube, called a ‘shunt’, into your skull to drain some of the excess fluid away. You may hear the term ‘ventricular catheter’, which is the name for the end of the shunt that goes into your brain.

The shunt has valves to make sure that it takes fluid in the correct direction, away from the brain and towards other parts of the body that can easily absorb it, such as the abdominal lining of the heart.

A shunt is not very visible from outside of the body, so other people will not know it is there unless you tell them. The shunt will normally run from behind your ear, or the top of your head at the front, to your abdomen or chest under the skin. There may be a lump behind your ear (where the valve is) and you can sometimes feel the shunt tubing beneath the skin on your neck, chest and abdomen. 

If a shunt is part of a child’s long-term treatment plan, it will usually be inserted in a way that allows for their growth. This means that they should not require new shunts as they grow.

What happens during shunt surgery?

Shunt surgery is carried out by a neurosurgeon and usually takes up to 2 hours. You will be put under general anaesthetic for this.

After the surgery, you might need to stay in hospital for a few days to recover. And, if you have non-dissolvable stitches or staples, you will likely have to go back to have those removed.

Variable shunts

The settings on some shunts can be changed. This is so the level of fluid drainage can be altered, if needed.

Make sure you know the settings, if you or your child has a variable/programmable shunt. This can be important if an MRI scan is needed, as the magnets in the scanner may cause the settings to change. Knowing the settings will help you check the correct settings have been reset following the scan.

Shunt alert cards/bracelets

You or your child may wish to wear a medical alert bracelet to inform others that they have a shunt, if they ever need to have a scan not related to their brain tumour. Medical bracelets are widely available in a range of different designs.

You can also get a shunt alert card for you or your child. This should always be carried around and will alert medical services of a shunt if necessary.

You can order a shunt alert card for free from Shine.

Endoscopic third ventriculostomy

Sometimes, inserting a shunt may not be the best way of treating excess fluid in the brain (hydrocephalus). An endoscopic third ventriculostomy (ETV) is a type of surgery, which avoids the need for a shunt. Like most types of brain surgery, an ETV is done while you are asleep. In this operation, your neurosurgeon will make a small hole in your skull, and use an endoscope (a long, thin tube with a light and camera at one end) to look inside the fluid filled chambers of your brain. Your surgeon will then make a hole through the wall of one of these chambers (the third ventricle). This will allow the trapped cerebrospinal fluid (CSF) to escape to the brain’s surface, where it will be reabsorbed. The endoscope will then be removed and the wound closed using stitches or staples.  

An ETV is not suitable for everyone, so speak to your medical team if you want to know whether this is appropriate for you.

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More information on neurosurgery

Neurosurgery (adults) – (pdf) –

Find out more about Neurosurgery for adults in the full fact sheet – including longer-term effects and information about when you can return to activities, such as sport or flying.

Neurosurgery (adults) – Clear print (pdf) –

Find out more about Neurosurgery for adults in the full fact sheet – including longer-term effects and information about when you can return to activities, such as sport or flying. Clear print version, designed to RNIB standards.

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