Burr Holes

What are burr holes?

Burr holes are small holes (the size of a dime) that a neurosurgeon makes in the skull. Burr holes can be used to 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 surrounds and help protect the brain. These meninges contain blood vessels that might bleed easily. The dura mater is the outermost of these meninges.

A head injury can cause one or more of the blood vessels on the surface of the brain or in the meninges to tear and bleed. A sudden tear might cause blood to build up very suddenly over a few hours. With a small tear, the blood might build up more slowly over weeks. 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. Because a subdural or epidural hematoma pushes on 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 long-term (chronic) 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, such as headache, changes in behavior, confusion, 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. But in many cases, burr holes are joined with a special saw to create a larger opening (craniotomy). Neurosurgeons may do a burr hole or a craniotomy procedure to ease pressure around the brain caused by:

A sudden (acute) subdural hematoma
An epidural hematoma
Certain kinds of brain cancer
Buildup of pus around the meninges
Hydrocephalus
Brain swelling (edema)
Certain kinds of bleeding from the brain itself

Talk with 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 more 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 get ready 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 CT scan or a MRI. This is done to get more information about the fluid around your brain.

Don't 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 or an illness.

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 IV (intravenous) line put in your arm or hand. You will receive 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 may or may not 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.
Each burr hole may be covered with a small metal plate.
The surgeon may 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. Don't do any activities that might cause a blow to the head. Don't 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. You might need repeat imaging, such as a brain CT or an MRI. Your medical team will watch your progress closely to see if you need a follow-up procedure to treat your condition.