Burr Hole Surgery

What Is a Burr Hole?

A burr hole is a hole that is surgically placed in the skull, also known as the cranium. Burr holes are placed to facilitate further surgery or maybe the only disruption in the skull, depending upon the nature of the issue. Quite simply, a burr hole is a small hole made in the skull with a surgical drill.

The burr hole, or often holes, is a necessary part of the vast majority of brain surgeries. Why? The skull is very hard, making a traditional incision with a scalpel impossible. A saw can be used to cut into the bone, but cutting the skull takes special skills and techniques to prevent injury to the brain. A burr hole makes it possible to make controlled cuts in the skull without risking penetrating trauma to the delicate brain tissues.

Think of the burr hole as the beginning of the incision to perform brain surgery, rather than the surgery itself. The burr hole makes it possible to "connect the dots" so surgeons can place multiple burr holes, then use a different tool to connect those holes and lift a section of the skull away. This leaves a window for the surgeon to work through.

Why Is a Burr Hole Used?

A burr hole is used when there is a problem with the brain that must be treated surgically. In order to access the brain tissue, the cranium (or skull) must be opened to allow access to the brain. In the majority of surgeries, placing a hole in the skull is the best way to treat the injury or illness.

There are many reasons why a surgeon would need to perform brain surgery that begins with a burr hole. Those reasons may include:

• To relieve pressure on the brain
• To begin a larger incision, such as a craniotomy
• To place a monitor that reads the pressure inside the skull
• To remove a blood clot
• To remove a tumor
• To treat seizures
• To remove a foreign object
• To place a medical device, such as a shunt or chemotherapy wafers

Risks of a Burr Hole Procedure

Burr hole placement has significant risks, in addition to the risks associated with all surgical procedures and anesthesia complications. As with any surgery, the risks of the procedure need to be weighed against the potential benefits. In some cases, the risk of permanent injury or even death may be the alternative to surgery, so that must be considered when deciding to have surgery.

In some cases—typically after a trauma or injuries to the brain—surgery may be performed as a last resort. In those cases, the risks of the procedure are very high, but not performing surgery may also result in death, so the decision is often a very difficult one.

The risks of surgery to place a burr hole include:

• Seizure
• Bleeding
• Stroke
• Infection of the incision or brain
• Bleeding of the brain
• Brain damage, including changes in the senses, memory problems, coordination difficulties, and speech impairments
• Swelling of the brain
• Coma

The Burr Hole Procedure

Burr hole surgery is performed by a neurosurgeon, a surgeon trained specifically in brain and spine surgery, known as the practice of neurosurgery.

To perform a burr hole procedure, the area of the scalp where it will be placed must be shaved clean of hair. Then the skin will be prepared with a special solution designed to eliminate germs on the surface of the skin. While the head may be shaved prior to surgery, the skin prep will be done in the operating room. This may be done either immediately before or after anesthesia is given, and is necessary to reduce the risk of infection. 

After the anesthesia provider has administered sedation, the patient will be intubated and placed on a ventilator, if they are not already receiving assistance with their breathing. This is done to protect the airway and to deliver oxygen during surgery. 

Within moments, the anesthesia will take effect, and the patient will be positioned for surgery. This is typically done in one of two ways: Either the head is supported on pillows or towels, or headpins may be used, which is a device that holds the head still in the position that is most suitable for surgery. A foley catheter is typically placed during this time, if not already in place prior to the procedure.

Once properly positioned, the initial incision is made in the scalp, so that the skin can be pulled away from the surgery site. A specialized air drill is then used to penetrate the skull. While the drill may seem like a standard drill, it is designed to stop drilling once the skull is penetrated, preventing injury to the brain.

Some brain surgeries, such as a ventriculostomy, require only one burr hole to perform the surgery. In other cases, an additional burr hole(s) may be placed, then the holes are connected using a special bone saw. This allows a section of the skull to be removed, a procedure is known as a craniotomy, which gives the surgeon more room to work on the brain.

Once the burr hole is completed, an additional incision must be made in the dura. The dura is the tough covering over the brain. While it appears to be a thin film, it is actually quite strong and must be moved aside.

The rest of the procedure is performed via the burr hole or the craniotomy. Once complete, the dura may be stitched together or the incision left open. The skin will be placed back into its normal position and stitches or staples used to close the incision.

Depending upon the nature of the surgery, the head may be wrapped with bandages or the area may be lightly covered with minimal dressings.

Recovery After Burr Hole Surgery

There is no standard recovery after the placement of a burr hole, as the reasons for the procedure vary widely. In severe cases, the patient may be unconscious and being treated in the ICU for days or even weeks after the procedure, while other patients may be awake and behaving normally shortly after emerging from anesthesia.

In most cases, the patient will recover in an ICU, such as a surgical ICU or neuro ICU, where they can be closely monitored by staff. This allows the patient to get constant attention from the nursing staff and for any signs of complications to be noted quickly.

Taking care of the incision will be of great importance, as an infection in the incision can easily reach the tissues of the brain. In most cases, antibiotics will be given to prevent an infection from occurring, even if there is no infection currently present.

The neurosurgeon performing the surgery will be your best source of information regarding what type of recovery should be expected. They will be able to take into account the patient's overall health, the seriousness of the injury that makes a burr hole necessary, as well as age, and other factors that play a role in the ability to make a full recovery.

A Word From Verywell

It is always serious when an individual needs a burr hole placed, whether it is for monitoring or to allow for more complicated surgery. You can almost always expect an intensive care stay to make constant monitoring possible, and the recovery may be a difficult one. Regardless of the reason for surgery, brain surgery is going to require significant recovery time for the patient when compared to more typical surgeries.