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Articles and graphics courtesy of Medtronic Sofamor Danek, 2002.

Craniotomy

What is it?
Craniotomy is the surgical opening of the cranium, the bones of the skull. Crani- refers to the cranium, and -otomy means to cut into.

Why is it done?
A craniotomy is performed to treat various brain problems surgically, such as tumors, aneurysms, blood clots, head injuries, and abscesses. The operation described and illustrated in this website is craniotomy for cerebral hemisphere tumors - tumors that occur around or inside the cerebrum.
The goal of all brain tumor surgery is to take out as much of the tumor as can safely be removed with as little injury to the brain as possible. This may be especially complicated if the boundaries of the tumor cannot easily be identified.

What happens afterwards?
For malignant brain tumors, radiation therapy and/or chemotherapy after surgery may be recommended.

Successful recovery from craniotomy for brain tumor requires that the patient and his family approach the operation and recovery period with confidence based on a thorough understanding of the process. The surgeon has the training and expertise to remove all or part of the tumor, if its removal is possible; however, recovery may at times be limited by the extent of damage already caused by the tumor and by the brain's ability to heal.

If a neurologic deficit remains, a period of rehabilitation will be necessary to maximize improvement. This process requires that the patient and his family maintain a strong, positive attitude, set realistic goals for improvement, and work steadily to accomplish each goal.

The Operation

After a general anesthetic has been given, the patient is positioned according to the area of the brain that must be reached. Often a dehydrating agent, such as Mannitol, is given - again in an attempt to control brain swelling. The operation usually is performed with the patient lying on his or her back. The hair over the incision area is then clipped and shaved.

Incision

A curved incision is made in the scalp over the appropriate location. The scalp flap is then laid back to expose the skull.

Craniotomy

Next, small burr holes are drilled in the skull with a power drill.

A surgical saw is used to connect the holes and create a "window" in the skull through which surgery will take place. The removed bone piece is kept sterile for replacement at the end of the operation.

Exposure of the brain

When the dura is exposed, an ultrasound probe is used to confirm the location and depth of the underlying tumor and help the surgeon plan his approach. Then the dura is cut with a scalpel or scissors and is laid back to uncover the brain, as seen in.

Removal of the tumor
The tumor is carefully dissected from normal brain tissue with special microsurgical instruments. For an intracranial tumor, a small incision is made through the surface of the brain and into brain tissue until the tumor is reached. Ultrasound frequently is used to monitor the tumor's removal.

Specialized instruments may be used by the neurosurgeon to visualize, cut into, and remove the tumor, including a surgical microscope or special magnification glasses, a surgical laser that vaporizes the tumor (literally causing it to "go up in smoke"), and an ultrasonic tissue aspirator that breaks apart and suctions up the abnormal tissue. At this time the biopsy is sent to the laboratory for analysis.

Unlike elsewhere in the body, where some extra tissue around a tumor may be surgically removed "just to be sure," only tissue that can clearly be identified as abnormal may be removed from the brain-and even then only if its removal is possible without devastating consequences. With meningioma and metastatic tumors, usually easy to distinguish from healthy dura and brain tissue around them, the surgeon is more likely to be able to "get it all" than in the case of glioma, where the boundaries of the tumor are unclear and may be impossible to identify.

Replacement of bone
After the dura has been stitched closed, the piece of bone is replaced and sutured into place. An ICP monitoring device may then be implanted.

Incision closure
The operation is completed when the incision is closed in several layers. Unless dissolving suture material is used, the skin sutures (stitches or staples) will have to be removed after the incision has healed.