Burr hole surgery is a procedure in which one or more arachnoid openings and burr holes are made over both cerebral hemispheres or in the skull. These burr holes are very important to make as they facilitate the further operation because it is impossible to make a traditional incision with the scalpel in the skull due to the hardness of the skull, so these burr holes are made by using a saw. Making these burr holes requires special techniques and skills to avoid any injury to the brain. A burr hole surgery also helps in relieving the pressure in the brain due to the fluid build up, such as blood, which can cause compression of the brain tissues which can be very dangerous for the life of the patient.
When is a Burr Hole Surgery Required?
Meninges are the layer of thin tissues that surround the brain to protect it and they contain blood vessels. A head injury can tear these blood vessels which lead to continuous bleeding within the brain leading to accumulation of blood just below the “Dura Mater” or “Dura,” which is the outermost layer of the meninges resulting in the formation of subdural hematoma. The speed at which the blood accumulates depends on the severity of the injury that causes the “subdural hematoma”. It also can be caused by the use of anticoagulant medications, small repetitive injuries to the head, consumption of excessive alcohol and age factor.
Burr Hole Surgery is needed to relieve the pressure in the skull caused by such build up which causes compression on the brain. This subdural hematoma leads to various life-threatening symptoms which are treated by the burr hole surgery:
- It makes the veins fragile and easy to break, especially in the older adults.
- One-sided muscle weakness.
- Behaviour changes.
- Brain damage.
Other Reasons for Using Burr Hole Surgery are:
- To remove the accumulated pus around the meninges.
- To treat the different bleeds from the brain itself.
- To place some medical devices like shunts or chemotherapy wafers.
- For treating several types of brain cancer.
- Epidural hematoma.
- For removing any foreign object.
- To place a monitor inside the skull that reads the pressure.
- To remove any blood clot inside the skull.
- To make large incisions for other surgeries such as craniotomy.
If the blood accumulates above the Dura layer due to a tear in different blood vessels then it causes a “epidural hematoma.” Hematoma word simply means a collection of blood in a particular area which leads to swelling. For the larger hematomas or solid clots, other types of surgeries are used, such as craniotomy and craniectomy, where instead of making burr holes a large piece of bone from the skull is removed for the surgery. But that kind of surgeries have a higher rate of complications than a burr hole surgery and generally used in the case of chronic subdural hematomas.
Risks Associated with Burr Hole Surgery
Generally, all types of surgeries are performed as a last resort because they are associated with some level of risk and sometimes it often leads to permanent injury or even death. The level of risks and problems from surgeries depend on the patient’s age, general health and the cause for surgery. Risks and complications associated with the burr hole procedure are:
- Seizures or fits.
- Further bleeding.
- Chances of stroke.
- Skull flap or infection of the incision.
- Brain inflammation.
- Deep vein thrombosis that is the blood clot in a leg vein.
- No relief in the symptoms which can lead to further surgeries such as a craniotomy.
- Problems from anesthesia.
- Brain damage which can cause coordination problems, memory issues, and speech impairments.
Procedure: How is Burr Hole Surgery Performed?
Neurosurgeon is a physician who is specialized in brain and spine surgery and performs the burr hole surgery. The following steps are undertaken to perform a burr hole surgery.
- Firstly the area of the scalp is shaved clean of hairs prior to the burr hole surgery.
- All the vital signs of the patient, such as heart rate and blood pressure, will be carefully watched by the doctors for a successful burr hole surgery.
- Then the general anesthesia is given to the patient so the person feels relaxed and sleepy.
- The patient will be kept on a supine position with head neutral and flexed for good exposure of calvaria also known as skullcap and the skin flap will be marked for the dissection.
- The skin will be prepared by the infiltration in the saline solution to prevent an infection and to make the dissection easier.
- Then initial multiple triangular incisions will be made on the skin to pull it away from the surgery site and to expose the bone.
By using a high-speed air drill, burr holes will be made in the skull. The number of burr holes to be made on the skull depends on the requirement of the surgery or on the area of the brain to be exposed. So it can be only one burr hole surgery that is known as ventriculostomy or it can be multiple burr hole surgery. Multiple burr hole surgery is also known as craniotomy, there are 5 burr holes made on both sides of the frontal, the temporal and parietal region, at least 3cm apart from the midline to avoid any injury in the sagittal sinus or superior longitudinal sinus.
Then the dura, which is a thin film but tough and quite strong covering over the brain will be opened by using the surgical microscope and is moved aside for the rest of the burr hole procedure. Meningeal arteries must be preserved from the injury while opening the dura to avoid the undesirable life-threatening consequences.
After the completion of the burr hole procedure, the opened dura layer will be stitched back together or in some cases, the incision is left open and the periosteal flaps (outer covering of the bone) will be laid over the exposed brain through the already made burr holes and skin will be replaced back to its position by using stitches or staples and the skull will be covered in two layers.
A comprehensive head dressing is required postoperatively. Dressing and bandaging depend upon the nature of the injury.
Recovery Period After The Burr Hole Surgery
After the burr hole surgery, dressing is kept for about 5 days and there should be no leakage of cerebrospinal fluid (CSF) after the operation. The time required for recovery from burr hole surgery varies in all the cases, but a child shows faster recovery rate and starts doing well after 6 months of the burr hole procedure. Some patients show good response after the surgery and they start doing normal functions just after a few days of the procedure, so they get a discharge from the hospital in 1 to 2 weeks; but some patients remain unconscious after the burr hole procedure and they have to be treated in the ICU until they start performing the normal functions properly post burr hole surgery.
Pain at the site of burr hole surgery is generally seen after the operation. For this, over-the-counter painkillers are prescribed to relieve the pain post burr hole surgery. Taking care of the wounds and incisions is the most important thing to do after the burr hole operation to avoid any kind of infection in the brain; so antibiotics are given to the patient for a couple of days.
Patients should take regular post-operative appointments from their healthcare provider and should follow all the recommendations for best recovery.
- Kawaguchi, T., Fujita, S., Hosoda, K., Shose, Y., Hamano, S., Iwakura, M. and Tamaki, N., 1996. Multiple burr-hole operation for adult moyamoya disease. Journal of neurosurgery, 84(3), pp.468-476.
- Okano, A., Oya, S., Fujisawa, N., Tsuchiya, T., Indo, M., Nakamura, T., Chang, H.S. and Matsui, T., 2014. Analysis of risk factors for chronic subdural haematoma recurrence after burr hole surgery: optimal management of patients on antiplatelet therapy. British journal of neurosurgery, 28(2), pp.204-208.
- Matsushima Y, Inaba Y. Moyamoya disease in children and its surgical treatment: Introduction of a new surgical procedure and its follow-up angiograms. Childs Brain. 1984;11:155–70. [PubMed]