Surgery for Adult Brain and Spinal Cord Tumors

Surgery on brain and spinal cord tumors 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.

Surgery 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.

Surgery alone or combined with radiation therapy may control or cure many types of tumors, including some low-grade astrocytomas, ependymomas, craniopharyngiomas, gangliogliomas, and meningiomas.

Tumors that tend to spread widely into nearby brain or spinal cord tissue, such as anaplastic 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 or chemotherapy, which might help these treatments work better. This could help prolong the person’s life, even if all of the tumor can’t be removed.

Surgery can also be done to help relieve some of the symptoms caused by brain tumors, particularly those caused by a buildup of pressure within the skull. These can include headaches, nausea, vomiting, and blurred vision. Surgery may also make seizures easier to control with medicines.

Surgery to remove the tumor may not be a good option in some situations, such as if the tumor is deep within the brain, if it's in a part of the brain that can’t be removed, such as the brain stem, or if a person can’t have a major operation for other health reasons.

Surgery is not very effective against some types of brain tumors, such as lymphomas, although it may be used to get a biopsy sample for diagnosis.

Craniotomy

A craniotomy is a surgical opening made in the skull. This is the most common approach for surgery to treat brain tumors. The person may either be under general anesthesia (in a deep sleep) or may be awake for at least part of the procedure (with the surgical area numbed) if brain function needs to be assessed during the operation.

Part of the head might be shaved before surgery. The neurosurgeon first makes a cut in the scalp over the skull near the tumor, and folds back the skin. A special type of drill is used to remove the piece of the skull over 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 might use MRI or CT scans taken before the surgery (or may use ultrasound once the skull has been opened) to help locate the tumor and its edges.

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.

Many devices can help the surgeon see the tumor and surrounding brain tissue. The surgeon often operates while looking at the brain through a special microscope. MRI or CT scans can be done before surgery (or ultrasound can be used once the skull has been opened) to map the area of tumors deep in the brain. In some cases, the surgeon uses intraoperative imaging, in which MRI (or other) images are taken at different times during the operation to show the location of any remaining tumor. This may allow some brain tumors to be resected more safely and extensively.

As much of the tumor is removed as possible while trying not to affect brain functions. The surgeon can use different techniques to lower the risk of removing vital parts of the brain, such as:

• Intraoperative cortical stimulation (cortical mapping): In this approach, the surgeon electrically stimulates parts of the brain in and around the tumor during the operation and monitors the response. This can show if these areas control an important function (and therefore should be avoided).
• Functional MRI: This type of imaging test (described in Tests for Brain and Spinal Cord Tumors in Adults) can be done before surgery to locate a particular function of the brain. This information can be used to identify and preserve that region during the operation.
• Fluorescence-guided surgery: For some types of tumors, such as glioblastomas, the patient can be given a special fluorescent dye before surgery. The dye is taken up by the tumor, which then glows when the surgeon looks at it under fluorescent lighting from the operating microscope. This lets the surgeon better separate tumor from normal brain tissue.
• Newer techniques: Newer types of MRI, as well as newer surgical approaches, might be helpful in some situations. Some of these are described in What’s New in Adult Brain and Spinal Cord Tumor Research?

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 allows a person to get follow-up MRIs [and will not set off metal detectors].)

You might have small tube (called a drain) coming out of the incision that allows 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, the patient’s general health, and whether other treatments are given. Healing around the surgery site usually takes several weeks.

Surgery to help with CSF flow blockage

If a tumor blocks the flow of cerebrospinal fluid (CSF), it can increase pressure inside the skull (known as increased intracranial pressure, or ICP). This can cause symptoms like headaches, nausea, and drowsiness, and may even be life-threatening. Surgery to remove the tumor can often help with this, but there are also other ways to drain away excess CSF and lower the pressure if needed.

For example, the neurosurgeon may put in a silicone tube called a shunt (sometimes referred to as a ventriculoperitoneal or VP shunt). One end of the shunt is placed in a ventricle of the brain (an area filled with CSF) and the other end is placed in the abdomen or, less often, the heart (and would then be referred to as a ventriculoatrial shunt). The tube runs under the skin of the neck and chest. The flow of CSF is controlled by a valve placed along the tubing.

Shunts can be temporary or permanent. They can be placed before or after the surgery to remove the tumor. Placing a shunt normally takes about an hour. As with any operation, complications might develop, such as bleeding or infection. Strokes are possible as well. Sometimes shunts get clogged and need to be replaced. The hospital stay after shunt procedures is typically 1 to 3 days, depending on the reason it is placed and the patient’s general health.

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 floor 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.

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. It 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

Surgery may also be used to insert a ventricular access catheter, such as an Ommaya reservoir, to help deliver chemotherapy directly into the CSF. 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. After the operation, doctors and nurses can use a thin needle to give chemotherapy drugs through the reservoir or to remove CSF from the ventricle for testing.

Possible risks and side effects of 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 and for several days after surgery 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 Living as a Brain or Spinal Cord Tumor Survivor).