Brain and spinal tumours

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Surgery for brain and spinal cord cancer

Surgery is the primary treatment for brain and spinal cord cancer. Surgery is used to:

  • potentially cure the cancer by completely removing the tumour
  • remove as much of the tumour as possible (debulk) before using other therapies
  • remove a sample of the tumour to confirm the diagnosis of cancer (a biopsy)
  • relieve symptoms related to the tumour
  • insert a plastic tube (shunt) to drain cerebrospinal fluid (CSF) to relieve pressure on the brain
  • place a special dome-shaped device (Ommaya reservoir) to remove CSF or give chemotherapy

The type of surgical procedure depends mainly on the:

  • size of the tumour
  • location of the tumour
  • suspected tumour diagnosis
  • person’s age and neurological status

Side effects of surgery depend on the type of surgical procedure.

Evaluation before surgery

A person with a brain or spinal cord tumour is evaluated very carefully before surgery. The neurological examination looks for any changes to normal functions, such as reflexes, speech, hearing, vision, thinking, movement, feeling and body functions.

The location of the tumour is carefully mapped out before surgery with a series of computed tomography (CT) scans or magnetic resonance imaging (MRI) pictures. This will help the surgeon decide if the tumour can be removed by surgery.

Some areas of the brain and spinal cord are difficult to reach or have functions that are too important to be damaged by an attempt to surgically remove the tumour. Tumours that cannot be removed are called inoperable.

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A craniotomy is surgery that opens the skull to remove a brain tumour. The goal of surgery is to remove as much of the tumour as possible without destroying important brain tissue or affecting brain functions.

  • The person will be under general anesthesia or may be awake for at least part of the surgery.
    • The person will be awake if the doctor needs to assess brain function.
    • Assessing brain function is called mapping.
  • During the operation, the surgeon makes an incision in the scalp. A piece of the skull is removed to expose the area where the brain tumour is growing. This piece of skull is often called the bone flap.
  • The surgeon then makes an incision in the covering of the brain (dura mater) and pulls it apart slightly to identify and reach the tumour.
  • The surgeon removes as much of the tumour as possible.
    • A special ultrasound machine is sometimes used to break up the tumour and make it easier to remove.
    • The surgeon may also use a special operating microscope that helps to identify the edges of the tumour.
    • Image-guided surgery may be used for some brain tumours. Images are repeatedly taken with MRI or CT scan during the operation to show the location of the tumour and the surgeon’s instruments.
  • Once the surgeon has removed as much of the tumour as possible, the dura mater is tightly stitched together, the piece of skull is replaced with small screws and plates and the scalp is closed with stitches (sutures) or staples.
  • If the brain is very swollen after surgery, the piece of skull may be replaced later, when the swelling has gone down.
  • Healing usually takes several weeks.

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Brain mapping

Brain mapping is done during a craniotomy when a tumour is near areas of the brain that control speech or motor function. Mapping is done by a technique called intraoperative cortical stimulation. The technique involves stimulating the surface of the brain with a mild electrical current to determine the function of a particular part of the brain. The procedure is painless. It produces temporary speech disturbance or twitching in the part of the body that is controlled by the area of the brain being stimulated. This information is then “mapped” so that the surgeon can avoid these areas when removing the tumour.

Speech mapping

Speech mapping tracks the areas around the tumour that are responsible for speech and understanding speech. After a general anesthetic is given, the surgeon opens the skull and dura mater to expose the brain. The person is then woken up so that they can talk to the surgeon and follow any instructions given during the mapping. When the mapping is finished, the person is given a general anesthetic again and the surgeon continues the operation to remove the tumour.

Motor mapping

Motor mapping tracks the areas around the tumour that are responsible for movement and reflexes. The person may remain under general anesthetic if the surgeon does not need direct feedback from the person. The surgeon stimulates the areas around the tumour with an electrical current and watches for any movement of the body. As with speech mapping, the surgeon uses the mapped areas as a guide when removing the brain tumour.

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External ventricular drain

An external ventricular drain (EVD), also called ventriculostomy, is a thin tube inserted through the skin and skull into a ventricle (fluid-filled chamber in the brain). It allows cerebrospinal fluid (CSF) to drain from the brain into a collection system or bag outside the body. An EVD is sometimes placed before or during surgery to remove a brain tumour to relieve a buildup of CSF. The EVD cannot be left in place permanently. It is typically removed when it is no longer needed or it is replaced with a shunt.

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Shunt placement

A shunt may be needed if the brain tumour is blocking the flow of cerebrospinal fluid (CSF) and causing extra fluid to build up in the brain (hydrocephalus). A shunt is a narrow, soft, flexible piece of tubing. It has a valve system that regulates the pressure of the CSF and prevents fluid from flowing back into the ventricles. Many shunts have reservoirs that may be used to remove CSF samples.

During surgery, the shunt is placed in a ventricle of the brain (an area filled with CSF). It leads from the ventricle to the scalp. From there, it runs under the skin, down the neck and into the abdominal cavity (not the stomach). The CSF that drains into the abdominal cavity is reabsorbed into the bloodstream.

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Endoscopic third ventriculostomy

An endoscopic third ventriculostomy (ETV) is a procedure in which the surgeon creates an opening and places a tube in the third ventricle to allow CSF fluid to flow around an obstruction. The surgeon uses an endoscope to navigate within the ventricle and create an internal bypass. ETV is sometimes used to treat a buildup of extra fluid in the brain (hydrocephalus). It can also be used to biopsy or remove tumours within the ventricles of the brain.

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Ommaya reservoir placement

An Ommaya reservoir is a small, dome-shaped device with a short tube (catheter) attached to it. The surgeon inserts the reservoir under the scalp and the catheter is threaded into a ventricle or cyst in the brain.

The reservoir may be used to:

  • remove extra CSF (to relieve pressure)
  • get samples of CSF
  • inject drugs, such as chemotherapy, into the CSF
    • The drugs then circulate in the CSF throughout the brain and spinal cord.
  • inject chemotherapy drugs directly into a tumour

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Laminectomy is surgery to open a bone of the spine (vertebra), which covers the spinal cord, to remove a spinal tumour.

  • During the operation, the surgeon makes an incision in the area of the spine over the tumour and removes the vertebra.
    • The approach is sometimes changed to access the tumour, which may involve:
      • removing a rib attached to a vertebrae
      • accessing the spinal cord through the chest or from behind the abdomen
  • The surgeon may need to make an incision in the covering of the spinal cord (dura mater) to reach the tumour.
  • The surgeon removes as much of the tumour as possible.
    • A microsurgical laser may be used to help remove some types of tumours.
    • An ultrasonic aspirator system, which produces high-frequency sound waves and suction, may be used to break up and remove the tumour.
    • Ultrasound may be done during surgery to accurately show the tumour margins and confirm that enough bone has been removed to reach the tumour.
  • Once the surgeon has removed as much of the tumour as possible, the dura mater (if opened) is tightly stitched together so the CSF cannot leak out. The muscles along the spine are also sewn back together.
  • Adjuvant therapy is started at least 3–4 weeks after surgery to give the wound time to heal properly.

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En bloc resection

En bloc resection is a technique in which the surgeon tries to remove the tumour in a single piece. The location of the tumour and how far it extends into surrounding tissues determine the amount of tumour that is removed. En bloc resection is used to remove some spinal cord tumours.

  • Marginal en bloc resection removes only the tumour (the surgeon tries not to remove any of the surrounding tissues).
  • Wide en bloc resection removes the tumour along with a layer of healthy tissue around the tumour.

During marginal or wide en bloc vertebral body resection, the entire vertebral body (the solid, central part of the vertebra) is removed. This technique is called a total en bloc spondylectomy (TES). A TES is performed through either a combined anterior-posterior approach (through both the back and the abdomen) or a posterior-only approach (through the back). In the posterior-only approach, the person is placed in a frame and in a prone position (lying face down). During the procedure:

  • All tissues (including soft tissue, muscle, ligaments and blood vessels) attached to the vertebra and rib around the tumour are carefully cut apart.
  • After all the tissues are separated, the vertebral body is detached and removed in one piece along with the entire tumour.
  • Once the tumour is removed, the surgeon reconstructs the vertebra to stabilize the spine.

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Stabilization of the spine

When part or all of a vertebra is removed, the spine is weakened (spinal instability). The spine must be reinforced (stabilized) so it can function properly.

If the vertebrae above and below the removed section are intact, the surgeon can stabilize the spine using fixation devices. These are special pins, plates, rods, hooks or distractible cages (implants that replace a vertebra). The surgeon attaches the fixation device to the bones above and below where the vertebra was removed.

If there is no stable bone that can be used to attach the fixation devices, people with spinal instability will remain in bed until a special brace is made and fitted for them.

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See a list of questions to ask your doctor about surgery.


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