Craniotomy

Definition
Purpose
Demographics
Description
Diagnosis/Preparation
Aftercare
Risks
Normal results
Morbidity and mortality rates
Alternatives

Definition

A craniotomy is a procedure to remove a lesion in the brain through an opening in the skull (cranium).

Purpose

A craniotomy is a type of brain surgery. It is the most commonly performed surgery for brain tumor removal. It also may be done to remove a blood clot (hematoma), to control hemorrhage from a weak, leaking blood vessel (cerebral aneurysm), to repair arterio-venous malformations (abnormal connections of blood vessels), to drain a brain abscess, to relieve pressure inside the skull, to perform a biopsy, or to inspect the brain.

Demographics

Because craniotomy is a procedure that is utilized for several conditions and diseases, statistical information for the procedure itself is not available. However, because craniotomy is most commonly performed to remove a brain tumor, statistics concerning this condition are given. Approximately 90% of primary brain cancers occur in adults, more commonly in males between 55 and 65 years of age. Tumors in children peak between the ages of three and 12. Brain tumors are presently the most common cancer in children (four out of 100,000).

Description

There are two methods commonly utilized by surgeons to open the skull. Either an incision is made at the nape of the neck around the bone at the back (occipital bone) or a curving incision is made in front of the ear that arches above the eye. The incision penetrates as far as the thin membrane covering the skull bone. During skin incision the surgeon must seal off many small blood vessels because the scalp has a rich blood supply.

The scalp tissue is then folded back to expose the bone. Using a high-speed drill, the surgeon drills a

KEY TERMS

Abscess— A localized collection of pus or infection that is walled off from the rest of the body.

Arteriogram— An x-ray study of an artery that has been injected with a contrast dye.

Arteriovenous malformation— Abnormal, direct connection between the arteries and veins. Arterio-venous malformations can range from very small to large.

Cerebral aneurysm— An abnormal, localized bulge in a blood vessel that is usually caused by a congenital weakness in the wall of the vessel.

Cranium— Skull; the bony framework that holds the brain.

Computed tomography (CT)— An imaging technique that produces three-dimensional pictures of organs and structures inside the body using a 360° x-ray beam.

Edema— An accumulation of watery fluid that causes swelling of the affected tissue.

Hematoma— An accumulation of blood, often clotted, in a body tissue or organ, usually caused by a break or tear in a blood vessel.

Hemorrhage— Very severe, massive bleeding that is difficult to control.

Magnetic resonance imaging (MRI)— An imaging technique that uses magnetic fields and radio waves to create detailed images of internal body organs and structures, including the brain.

pattern of holes through the cranium (skull) and uses a fine wire saw to connect the holes until a segment of bone (bone flap) can be removed. This gives the surgeon access to the inside of the skill and allows him to proceed with surgery inside the brain. After removal of the internal brain lesion or other procedure is completed, the bone is replaced and secured into position with soft wire. Membranes, muscle, and skin are sutured into position. If the lesion is an aneurysm, the affected artery is sealed at the leak. If there is a tumor, as much of it as possible is resected (removed). For arteriovenous malformations, the abnormality is clipped and the repair redirects the blood flow to normal vessels.

Diagnosis/Preparation

Since the lesion is in the brain, the surgeon uses imaging studies to definitively identify it. Neuroimaging is usually accomplished by the following:

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

The procedure is performed in a hospital with a neurosurgery department and an intensive care unit. The procedure is performed by a board certified neurosurgeon, who has completed two years of general surgery training and five years of neurosurgical training.

• CT (computed tomography, uses x-rays and injection of an intravenous dye to visualize the lesion)
• MRI (magnetic resonance imaging, uses magnetic fields and radio waves to visualize a lesion)
• arteriogram (an x-ray of blood vessels injected with a dye to visualize a tumor or cerebral aneurysm)

Before surgery the patient may be given medication to ease anxiety and to decrease the risk of seizures, swelling, and infection after surgery. Blood thinners (Coumadin, heparin, aspirin ) and nonsteroidal anti-inflammatory drugs (ibuprofen, Motrin, Advil, aspirin, Naprosyn, Daypro) have been correlated with an increase in blood clot formation after surgery. These medications must be discontinued at least seven days before the surgery to reverse any blood thinning effects. Additionally, the surgeon will order routine or special laboratory tests as needed. The patient should not eat or drink after midnight the day of the surgery. The patient’s scalp is shaved in the operating room just before the surgery begins.

Aftercare

Craniotomy is a major surgical procedure performed under general anesthesia. Immediately after surgery, the patient’s pupil reactions are tested, mental status is assessed after anesthesia, and movement of the limbs (arms/legs) is evaluated. Shortly after surgery, breathing exercises are started to clear the lungs. Typically, after surgery patients are given medications to control pain, swelling, and seizures. Codeine may be prescribed to relive headache. Special leg stockings are used to prevent blood clot formation after surgery. Patients can usually get out of bed in about a day after surgery and usually are hospitalized for five to 14 days after surgery. The bandages on the skull are removed and replaced regularly. The sutures closing the scalp are removed by the surgeon, but the soft wires used to reattach the portion of the skull that was removed are permanent and require no further

QUESTIONS TO ASK THE DOCTOR

How is this procedure done? What kinds of tests and preparation are necessary before surgery? What risks are associated with the procedure? How often is normal brain tissue damaged during this type of surgery? What is the expected outcome of the surgery? What complications may result from this type of surgery? What is the recovery time? How many of these procedures have you done in the past year?

attention. Patients should keep the scalp dry until the sutures are removed. If required (depending on area of brain involved), occupational therapists and physical therapist assess, the patient’s status postoperatively and help the patient improve strength, daily living skills and capabilities, and speech. Full recovery may take up to two months, since it is common for patients to feel fatigued for up to eight weeks after surgery.

Risks

The surgeon will discuss potential risks associated with the procedure. Neurosurgical procedures may result in bleeding, blood clots, retention of fluid causing swelling (edema), or unintended injury to normal nerve tissues. Some patients may develop infections. Damage to normal brain tissue may cause damage to an area and subsequent loss of brain function. Loss of function in specific areas can cause memory impairment. Some other examples of potential damage that may result from this procedure include deafness, double vision, numbness, paralysis, blindness, or loss of the sense of smell.

Normal results

Normal results depend on the cause for surgery and the patient’s overall health status and age. If the operation was successful and uncomplicated recovery is quick, since there is a rich blood supply to the area. Recovery could take up to eight weeks, but patients are usually fully functioning in less time.

Morbidity and mortality rates

There is no information about the rates of diseases and death specifically related to craniotomy. The operation is performed as a neurosurgical intervention for several different diseases and conditions.

Alternatives

There are no alternative treatments if a neurosurgeon deems this procedure as necessary.

Resources

BOOKS

Connolly, E. Sanders, ed. Fundamentals of Operative Techniques in Neurosurgery. New York: Thieme Medical Publishers, 2002.

Greenberg, Mark S. Handbook of Neurosurgery. 5th ed. New York: Thieme Medical Publishers, 2000.

Miller, R. Anesthesia. 5th ed. Philadelphia, PA: Churchill Livingstone, 2000.

PERIODICALS

Gebel, J. M., and W. J. Powers. “Emergency Craniotomy for Intracerebral Hemorrhage: When Doesn’t It Help and Does It Ever Help?” Neurology 58 (May 14, 2002): 1325–1326.

Mamminen, P., and T. K. Tan. “Postoperative Nausea and Vomiting After Craniotomy for Tumor Surgery: A Comparison Between Awake Craniotomy and General Anesthesia.” Journal of Clinical Anesthesia 14 (June 2002): 279–283.

Osguthorpe, J. D., and S. Patel, eds. “Skull Base Tumor Surgery.” Otolaryngologic Clinics of North America 34 (December 2001).

Rabinstein, A. A., J. L. Atkinson, and E. F. M. Wijdicks. “Emergency Craniotomy in Patients Worsening Due to Expanded Cerebral Hematoma: To What Purpose?” Neurology 58 (May 14, 2002): 1367–1372.

ORGANIZATIONS

American Association of Neurological Surgeons. 5550 Meadowbrook Drive, Rolling Meadows, IL 60008. (888) 566-AANS (2267). Fax: (847) 378-0600. E-mail: [email protected]. http://www.neurosurgery.org/aans/index.asp.

Laith Farid Gulli, M.D., M.S.

Nicole Mallory, M.S., PA-C

Robert Ramirez, B.S.

Creatine kinase test seeCardiac marker tests