Surgery to remove blood that collects in the brain
BMJ Group Medical Reference
This information is for people who have a haemorrhagic stroke. It tells you about surgery to remove blood that collects in the brain, a treatment used for this type of stroke. It is based on the best and most up-to-date research.
Does it work?
It's hard to say whether surgery will do you any good. Some research suggests it may reduce your risk of dying or having to depend on someone else for your care after a stroke. But we need more evidence.
Doctors think that surgery is the right treatment for some people who've had a haemorrhagic stroke. So they do recommend it sometimes. But there's not much research looking at which groups of people can benefit most from surgery.
What is it?
When an artery in your brain bursts during a haemorrhagic stroke, a pool of blood collects in your brain. This blood then clots and becomes a solid mass. Doctors call this clotted blood a haematoma.
To learn more about the different types of strokes, see What is a stroke?
Bleeding in your brain (a haemorrhage) can cut off the blood supply to another part of your brain. It can also kill brain cells directly. The clot that forms (the haematoma) can also lead to brain damage. For this reason, doctors may decide to drain the blood if they think it will reduce damage to the brain. However, they are still not certain whether this is a good idea.
Surgery is used more often to treat a brain haemorrhage in some parts of the world than others. In Germany and Japan about half of all people with a haemorrhage in the top, front part of the brain have surgery. In other parts of the world only about 3 in 100 of those people are operated on. 
In this section we look at operations that are sometimes used to treat blood clots found in two different parts of the brain.
The names of the operations used to drain pools of blood are given below. Surgery to drain blood is sometimes called evacuation.Craniotomy
A craniotomy is a cut made into the skull (which is also known as the cranium). This is done after a CT scan (a type of x-ray), so that doctors can check where the blood clot is. The doctors then make a hole in the skull that allows them to get near the blood clot. This hole reduces the pressure inside the brain that would otherwise build up as the pool of blood got bigger. It also allows doctors to drain the blood from the brain.Endoscopy