What are burr holes?

Burr holes are small holes that a neurosurgeon makes in the skull. Burr holes are used to help relieve pressure on the brain when fluid, such as blood, builds up and starts to compress brain tissue.

A layer of thin tissues called meninges surround and help protect the brain. These meninges contain blood vessels that carry blood to and from the brain. The dura is the outermost of these meninges.

A head injury can cause one or more of these blood vessels to tear and bleed. A sudden tear might cause blood to build up very suddenly. With a small tear, the blood might build up more slowly. Blood might start to build up just below the dura mater. This causes something called a subdural hematoma. Tears in different blood vessels may cause blood to build up just above the dura layer, causing an epidural hematoma. A hematoma is when blood collects in an area and causes swelling.

This buildup of blood is dangerous. As the blood builds, it pushes up against the skull and has nowhere to go. If the blood starts to compress the brain, it can lead to symptoms or even death if not treated.

Why might I need burr holes?

One of the most common reasons burr holes are needed is for a subdural hematoma. This is when blood slowly builds up under the dura layer after a mild head injury. The veins here are fragile and easy to break, especially in older adults. This can lead to symptoms like headache, changes in behavior, seizures, and one-sided muscle weakness. If the blood continues to build, it may cause coma and brain damage. 

There are other reasons why you might need a burr hole procedure. Neurosurgeons may perform a burr hole procedure to relieve pressure around the brain due to:

• A sudden (acute) subdural hematoma
• An ongoing (chronic) subdural hematoma
• An epidural hematoma
• Certain kinds of brain cancer
• Buildup of pus around the meninges
• Hydrocephalus
• Certain kinds of bleeds from the brain itself (rare)

In cases of large hematomas or solid clots, your healthcare provider may advise another procedure to remove the material around the brain. For example, a surgeon may remove a larger piece of bone from the skull to treat the brain, and then put the piece of skull back in place to heal. This is called a craniotomy. Or, the surgeon may not put the bone back in place. This is called a craniectomy.

These types of surgery may have a higher rate of complications than a burr hole procedure. They may be needed if you have chronic subdural hematomas. Talk to your healthcare provider about what makes sense for you.

What are the risks of a burr hole procedure?

All surgery has risks. The risks of a burr hole procedure include:

• Bleeding
• Infection
• Blood clots
• Brain injury
• Heart attack or stroke
• Problems with anesthesia
• No relief from symptoms and need for a surgery such as a craniotomy

Your own risks may vary according to your age, your general health, and the reason for your procedure. Talk with your healthcare provider to find out what risks may apply to you.

How do I prepare for a burr hole procedure?

In some cases, a burr hole procedure happens as an emergency treatment. If the procedure is planned, talk with the healthcare provider about what you should do to prepare.

Tell your healthcare provider about all the medicines you take. This includes over-the-counter medicines such as aspirin. You may need to stop taking some medicines ahead of time, such as blood thinners. If you smoke, you’ll need to stop before your surgery. Smoking can delay healing. Talk with your healthcare provider if you need help to stop smoking.

You may need some tests before the procedure, such as a computed tomography (CT) scan. This is done to get more information about the fluid around your brain.

Do not eat or drink after midnight the night before your procedure. Tell your healthcare provider about any recent changes in your health, such as a fever.

What happens during a burr hole procedure?

A burr hole procedure is most often done by a neurosurgeon who works with a team of specialized nurses. In some cases, a healthcare provider other than a neurosurgeon might need to perform the procedure. This may be the case if you have a medical emergency. The details of the procedure may vary from person to person, but a typical procedure goes like this:

• Just before the procedure, you’ll have an intravenous (IV) line put in your arm or hand. You will receive a medicine through the IV to make you relaxed and sleepy. Or, you will receive a medicine to make you sleep fully (general anesthesia).
• During the procedure, your healthcare provider will carefully watch your vital signs, such as heart rate and blood pressure.
• Hair will be trimmed in the area of the scalp.
• Numbing medicine is injected into the scalp.
• An incision is made in the scalp.
• Using a special drill, a surgeon drills one or two small holes in the skull to expose the dura.
• The surgeon then opens the dura and drains any excess fluid to reduce pressure within the skull.
• The surgeon may then place a temporary drain to continue to drain the fluid. Or the dura and scalp will be closed right away.

What happens after a burr hole procedure?

After your procedure, your healthcare provider will carefully watch your vital signs. You may need to stay in the hospital for a few days as you recover. Your original symptoms may go away quickly from the lowered pressure on your brain. 

You may have some pain at the site of your scalp incision. Over-the-counter pain medicines are often enough to treat it. 

You should be able to drink and eat normally after the surgery. You can resume most of your activities as soon you are able. Avoid any activities that might cause a blow to the head. Do not drive again until your healthcare provider says it is OK. Your healthcare provider may give you more instructions about caring for your wound or about your medicines.

Let your healthcare provider know right away about symptoms such as:

• Seizure
• Muscle weakness
• Confusion
• Fever or stiff neck
• Swelling, redness, or opening of your scalp incision

Make sure to go to all your follow-up appointments. You may need to have a drain or stitches removed. Your medical team will watch your progress closely, to see if you need a follow-up procedure to treat your condition.

Next steps

Before you agree to the test or the procedure make sure you know:

• The name of the test or procedure
• The reason you are having the test or procedure
• What results to expect and what they mean
• The risks and benefits of the test or procedure
• What the possible side effects or complications are
• When and where you are to have the test or procedure
• Who will do the test or procedure and what that person’s qualifications are
• What would happen if you did not have the test or procedure
• Any alternative tests or procedures to think about
• When and how will you get the results
• Who to call after the test or procedure if you have questions or problems
• How much will you have to pay for the test or procedure