Surgery for Brain Tumors in Adults

Surgery is part of the treatment for most people with brain tumors or spinal cord tumors. Surgery may be done to:

• Get a biopsy sample to determine the type of tumor
• Remove the tumor (or as much of it as possible)
• Help prevent or treat symptoms or possible complications from the tumor

Before surgery, be sure you understand the goal of the surgery, as well as its possible benefits and risks.

Craniotomy to remove the tumor

Most often, the first step in brain or spinal cord tumor treatment is for the neurosurgeon to remove as much of the tumor as is safe without affecting normal brain function. This is known as a maximal safe resection. It is most often done with a craniotomy, a surgical opening made in the skull.

Surgery can also help relieve brain tumor symptoms caused by a buildup of pressure within the skull, such as headaches, nausea, vomiting, and blurred vision. Surgery may also make seizures easier to control with medicines.

Which types of brain tumors can be removed?

For some types of tumors, the surgeon may be able to remove all of it, but for other types this isn’t usually possible.

Surgery alone or combined with radiation therapy may control or cure many types of tumors, including:

• Some low-grade astrocytomas
• Ependymomas
• Craniopharyngiomas
• Gangliogliomas
• Meningiomas

Tumors that tend to spread widely into nearby brain or spinal cord tissue, such as higher-grade astrocytomas or glioblastomas, typically cannot be cured by surgery. But surgery is often done first to reduce the amount of tumor that needs to be treated by radiation and/or chemotherapy, which might help these treatments work better. This can often help a person live longer.

Surgery is not usually done to treat certain types of brain tumors, such as CNS lymphomas, although it may be used to get a biopsy sample for diagnosis.

Surgery to remove the tumor may not be a good option in some situations, such as when:

• The tumor is deep within the brain
• It's in a part of the brain that can’t be removed, such as the brain stem
• The person can’t have a major operation for other health reasons

How is a craniotomy done?

For a craniotomy, a surgical opening is made in the skull. You may be under general anesthesia (in a deep sleep) during the operation, or awake for at least part of the procedure (with the surgical area numbed) if brain function needs to be assessed during the operation. This is known as an awake craniotomy (see below).

Opening the skull

Part of the head might be shaved before surgery. The neurosurgeon then makes a cut in the scalp and folds back the skin. A special drill is used to remove a piece of the skull over the tumor.

Locating the tumor

The opening is typically large enough for the surgeon to insert several instruments and see the parts of the brain needed to operate safely. The surgeon may need to cut into the brain itself to reach the tumor.

The surgeon often operates while looking at the brain through a special microscope. MRI or CT scans can be done before surgery to map the area of tumors deep in the brain, or ultrasound can be used once the skull has been opened.

Avoiding vital parts of the brain

The surgeon can use different techniques to lower the risk of removing vital parts of the brain, such as:

• Functional MRI (fMRI) and diffusion tensor imaging (DTI): These imaging tests can be done before surgery to locate important parts of the brain and help the surgeon avoid them during the operation.
• Intraoperative cortical stimulation (cortical mapping): The surgeon electrically stimulates parts of the brain in and around the tumor during the operation and monitors the response. This can show whether these areas control an important function and should be avoided.
• Awake craniotomy: The person is gently awakened during the operation when the surgeon needs to work near areas that control essential functions like speech, movement, or vision. The surgeon will ask them to do simple tasks, like talking or moving a hand, to see which brain areas need to be avoided.
• Intraoperative MRI: The operation is done in a special room with an MRI scanner. MRIs can be done at different times during the operation to show the location of any remaining tumor. This may allow some brain tumors to be removed more safely and extensively.
• Fluorescence-guided surgery: For some types of tumors, such as glioblastomas, the person can be given a special fluorescent dye before surgery. The dye is taken up by the tumor, which then glows under the operating microscope’s fluorescent lighting. This can help the surgeon tell tumor from normal brain tissue.

Removing the tumor

The surgeon can remove the tumor in different ways depending on how hard or soft it is, and whether it has many or just a few blood vessels:

• Many tumors can be cut out with a scalpel or special scissors.
• Some tumors are soft and can be removed with suction devices.
• In other cases, a handheld ultrasonic aspirator can be placed into the tumor to break it up and suck it out.

Closing the skull

Once the surgery is complete, the piece of the skull bone is put back in place and fastened with metal screws and plates, wires, or special stitches. Usually, any metal pieces are made from titanium, which does not set off metal detectors and is safe for MRI machines.

Other surgical approaches

Depending on where the tumor is, other approaches might be used. For example, tumors lower in the brain or near the base of the skull can sometimes be reached through a smaller hole, such as above an eyebrow or even inside the nose. An endoscope (a thin tube with a tiny video camera on the end) might then be used to see the tumor during the operation.

Regardless of the approach, as much of the tumor is removed as possible while trying not to affect brain function.

What to expect after surgery

You might have a small tube (called a drain) coming out of the incision to allow excess cerebrospinal fluid (CSF) to leave the skull. Other drains may be in place to allow blood that builds up after surgery to drain from under the scalp. These drains are usually removed after a few days.

An imaging test such as an MRI or CT scan is typically done 1 to 3 days after the operation to confirm how much of the tumor has been removed.

Recovery time in the hospital is usually 4 to 6 days, although this depends on the size and location of the tumor, your overall health, and whether other treatments are given. Healing around the surgery site usually takes several weeks.

Laser interstitial thermal therapy (LITT)

For some tumors that are hard to treat surgically, another option might be to insert a thin probe with a tiny laser on the end through a small hole in the skull and into the tumor. The probe is guided into place using MRI. The laser is then used to heat and destroy (ablate) the tumor while limiting damage to nearby healthy tissue.

This technique is still fairly new, so doctors are still learning about the best situations to use it.

Surgery to help lower pressure inside the skull

If a tumor blocks the flow of cerebrospinal fluid (CSF), it can increase pressure inside the skull. This increased intracranial pressure (ICP) can cause symptoms like headaches, nausea, and drowsiness, and may even be life-threatening.

Removing the tumor can often help with this, but there are also other ways to drain away excess CSF and lower the pressure if needed.

Shunt placement

To help relieve pressure caused by a buildup of CSF, the neurosurgeon may place a small silicone tube called a shunt. One end of the shunt is placed in a ventricle of the brain (a space filled with CSF). The tube is then tunneled under the skin of the neck and chest, with the other end draining into the abdomen (a ventriculoperitoneal shunt or VP shunt) or, less often, into the heart (a ventriculoatrial shunt or VA shunt). A one-way valve along the tubing helps control the flow of CSF.

Placing a shunt normally takes about an hour. This may be done either before or after surgery to remove the tumor.

As with any operation, complications might develop, such as bleeding or infection. Strokes are possible as well. The hospital stay after shunt procedures is typically 1 to 3 days, depending on the reason it is placed and the person’s general health.

Shunts can be temporary or permanent. Sometimes they can become clogged and need to be replaced.

Endoscopic third ventriculostomy (ETV)

Another option to treat increased pressure in the skull in some cases is an endoscopic third ventriculostomy (ETV). In this operation, an opening is made in the bottom of the third ventricle at the base of the brain to allow the CSF to flow again. This operation is done through a small hole in the front of the skull. An advantage of this approach is that it does not require a shunt. But there is also a chance that the opening made in the ventricle might close up again, which is more likely in people with brain tumors.

External ventricular drain (EVD)

If the pressure inside the head needs to be relieved for a short time, an external ventricular drain (EVD) might be put in place to allow the excess CSF to drain out. The drain is a small tube. One end is put into a ventricle, and the other end is attached to a collection bag outside the body. Along with collecting the excess CSF, the drain can also be used to measure the pressure inside the skull, as well as to look for tumor cells, blood, or signs of infection in the CSF.

The drain can be placed either during surgery or during a procedure at the patient's bedside.

An EVD can be put in place to relieve the pressure in the days before surgery, or to help drain the fluid that collects after an operation.

If the pressure inside the skull needs to be lowered for more than a few days, the doctor might need to change this to a VP shunt.

Surgery to put in a ventricular access catheter

If chemotherapy is needed, surgery may be done to insert an Ommaya reservoir or other ventricular access catheter under the scalp.

To place the reservoir, a small incision is made in the scalp, and a small hole is drilled in the skull. A flexible tube is then threaded through the hole until the open end of the tube is in a ventricle, where it reaches the CSF. The other end, which has a dome-shaped reservoir, stays just under the scalp.

Once it’s placed, a doctor or nurse can use a thin needle to give chemotherapy drugs through the reservoir or remove CSF from the ventricle for testing.

Possible risks and side effects of brain tumor surgery

Surgery on the brain or spinal cord is a serious operation, and surgeons are very careful to try to limit any problems either during or after surgery. Complications during or after any type of surgery can include bleeding, infections, or reactions to anesthesia, although these are not common.

A major concern after surgery is swelling in the brain. Drugs called corticosteroids are typically given before surgery and for several days after to help lessen this risk.

Seizures are also possible after brain surgery. Anti-seizure medicines can help lower this risk, although they might not prevent them completely.

One of the biggest concerns when removing brain tumors is the possible loss of brain function afterward, which is why doctors are very careful to remove only as much tissue as is safely possible. If problems do arise, it could be right after surgery, or it could be days or even weeks later, so close monitoring for any changes is very important. (See After Brain Tumor Treatment.)