For brain and spinal cord tumors, surgery may be done for different reasons:
- To get a biopsy sample to determine the type of tumor
- To remove as much of the tumor as possible
- To help prevent or treat possible complications from the tumor
Before surgery, be sure you understand what the goal of the surgery is, as well as the potential benefits and risks.
Surgery to remove the tumor
In most cases, the first step in brain tumor treatment is an operation called a craniotomy to remove as much of the tumor as possible. Surgery alone or combined with radiation therapy may cure many tumors, including some low-grade astrocytomas, pleomorphic xanthoastrocytomas, dysembryoplastic neuroepithelial tumors, ependymomas, craniopharyngiomas, gangliogliomas, and meningiomas.
Children with infiltrating tumors (tumors that grow into surrounding areas), such as anaplastic astrocytomas or glioblastomas, cannot be cured by surgery alone. But surgery can reduce the amount of tumor that needs to be treated by radiation or chemotherapy, which might improve the results of these treatments.
Surgery may also improve some of the symptoms caused by brain tumors, particularly those caused by increased pressure within the skull. These can include headaches, nausea, vomiting, and blurred vision. Surgery may also make seizures easier to control with medicines.
Surgery may not be a good option in some cases, such as if the tumor is deep within the brain, or if it is in a part of the brain that can't be removed, such as the brain stem. If this is the case, other treatments may be used instead.
Craniotomy: A craniotomy is a surgical opening made in the skull. This is the most common surgery to remove a brain tumor. For this operation, the child may either be under general anesthesia (in a deep sleep) or may remain awake (with the surgical area numbed) if brain function needs to be assessed during the operation. Part of the head may need to be shaved.
The neurosurgeon makes an incision in the scalp and then uses a special type of drill to remove a piece of bone from the skull over the tumor. Many devices can help the surgeon see the tumor and surrounding brain tissue. The surgeon often operates while looking at the brain through a microscope. In some cases, imaging tests such as MRI, CT, or ultrasound can be used to help locate tumors buried deep in the brain.
Once the tumor is located, the surgeon removes as much as is safely possible. This can be done in several ways depending on how hard or soft the tumor is, and whether it contains many or just a few blood vessels. One way is to cut it out with a scalpel or special scissors. Some tumors are soft and can be removed with simple suction devices. In other cases, a probe attached to an ultrasonic generator may be placed into the tumor to break it up and liquefy it. A small vacuum device is then used to suck it out.
The surgeon is very careful to avoid damaging normal brain tissue as much as possible. The surgeon can often detect the function of brain areas in and around the tumor by electrically stimulating them and monitoring the response. This will show if these areas control an important function, helping the surgeon to avoid them. In some cases, the surgeon may use 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 can allow some brain tumors to be resected more safely and extensively. After removing the tumor, the surgeon replaces the bone and closes the incision.
After the operation, the child may have 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. The drains are usually removed after a few days. Recovery time in the hospital is usually 4 to 6 days, but this may vary according to the size and location of the tumor and whether other treatments are given.
Surgery to place a shunt or ventricular access catheter
If the tumor blocks the CSF flow it can cause increased pressure inside the skull. This can cause symptoms such as headaches, nausea, vomiting, and blurred vision, and may even permanently damage the brain.
To drain away excess CSF and lower the pressure, 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. 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 may be temporary or permanent. They may be placed before or after the surgery to remove the tumor.
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 inserted 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, remains 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. Symptoms of brain injury after surgery depend on the location of the lesion. Complications during surgery such as bleeding or reactions to anesthesia are rare, but they can happen.
Swelling in the brain is a major concern after surgery. Drugs called corticosteroids are typically given for several days after surgery to help lessen this risk.
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 necessary.
For more extensive information on surgery as a treatment for cancer, see our separate document, Surgery.
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