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Craniotomy

 

        

What is a craniotomy?

Craniotomies are named according to the area of skull (cranium) to be removed. After the surgeon repairs the problem, the bone flap is then replaced or covered with plates and screws. If the bone flap is not replaced, the procedure is called a craniotomy.

Burr Hole Craniotomies

Small dime-sized craniotomies are called burr holes; “keyhole” craniotomies are quarter-sized or larger. Stereotactic frames, image-guided computer systems, or endoscopes may be used to precisely place instruments through these small holes. Burr holes and keyholes are used for minimally invasive procedures to:

  • insert a shunt into the ventricle to drain cerebrospinal fluid (to treat hydrocephalus)
  • insert a deep brain stimulator (DBS)
  • insert an intracranial pressure (ICP) monitor
  • remove a sample of tissue cells (needle biopsy)
  • drain a blood clot (hematoma aspiration)
  • insert an endoscope to remove tumors

Complex Skull Base Craniotomies

Complex skull base craniotomies involve the removal of bone that supports the bottom of the brain where delicate cranial nerves, arteries, and veins exit the skull. Reconstruction of the skull base may require the additional expertise of head-and-neck, otologic, or plastic surgeons. Surgeons often use image-guidance systems and endoscopes to plan the access for difficult-to-reach lesions to:

  • remove deep tumors or AVMs; clip aneurysms
  • remove tumors that invade the body skull

While most skull openings are made as small as possible, large decompressive craniotomies are made to allow the brain to swell after a head trauma or stroke. The bone flap is frozen and replaced months after recovery (cranioplasty).

Awake craniotomies are performed when a lesion is close to critical speech areas. The patient is asleep for the bone opening and then awakened to help the surgeon map areas at risk. A probe is placed on the brain surface while you read or talk. Called brain mapping, this process identifies your unique brain areas for speech and helps the surgeon avoid and protect these functions.

How do I prepare for a craniotomy?

In the doctor’s office you will review the procedure with your neurosurgeon and have time to ask questions. Consent forms are signed and paperwork complete to inform the surgeon about your medical history (e.g., allergies, medicine, anesthesia reactions, previous surgeries). Several days before surgery, your primary care physician will conduct tests (e.g., electrocardiogram, chest x-ray, and blood work) to make sure that you are cleared for surgery.

It is important that you discontinue all non-steroidal anti-inflammatory medicines (Naproxen, Advil, etc.) and blood thinners (Coumadin, heparin, aspirin, Plavix, etc.), typically at least 1 week before surgery. Additionally stop smoking, chewing tobacco, and drinking alcohol 1 week before and 2 weeks after surgery as continuing these activities can lead to bleeding issues.

If image-guided surgery is planned, an MRI will be scheduled before surgery. Fiducials (small markers may be placed on your forehead and behind the ears. The markers help align the preoperative MRI to the image guidance system. The fiducials must stay in place and cannot be moved or removed prior to surgery to ensure the accuracy of the scan. 

What should I expect during a craniotomy?

You will be given general anesthesia while lying on the operating table. After you fall asleep, your head is placed in a 3-pin skull fixation device that attaches to the table and holds your head still during surgery. A brain-relaxing drug called mannitol may be given. 

If image-guidance is used, your head will be registered with the infrared cameras to correlate the “real patient” to the 3D computer model created from your MRI scans. The system functions as a GPS to help plan the craniotomy and locate the lesion. Instruments are detected by the cameras and displayed on the computer model.

The incision area of the scalp is prepped with an antiseptic. Skin incisions are usually made behind the hairline. A hair sparing technique is used, where only 1/4 -inch wide area along the proposed incision is shaved. Sometimes the entire incision area may be shaved.

Small burr holes are made in the skull with a drill. The burr holes allow entrance of a special saw called a craniotome. Similar to using a jigsaw, the surgeon cuts an outline of a bone window. The cut bone flap is lifted and removed to expose the protective covering of the brain called the dura. The bone flap is safely set aside and will be replaced at the end of the surgery.

After the problem has been removed or repaired, any retractors are removed, and the dura is closed with sutures. The bone flap is put back in its original position and secured to the skull with titanium plates and screws. The plates and screws remain permanently to support the area, and they sometimes can be felt under your skin. A drain may be placed under the skin for a couple of days to remove blood or fluid from the area. The muscles and skin are sutured back together. A soft adhesive dressing is placed over the incision.

What should I expect after a craniotomy?

After surgery, you are taken to the recovery room where vital signs are monitored as you awake from anesthesia. The breathing tube (ventilator) usually remains in place until you fully recovery from the anesthesia. Next, you are moved to the neuroscience intensive care unit (NSICU) for close monitoring. You are frequently asked to move your arms, fingers, toes, and legs. A nurse will check your pupils with a flashlight and ask questions. This might include asking your name, birthday, etc. You may experience nausea and headache after surgery. Medication can control these symptoms depending on the type of brain surgery, steroid medication (to control brain swelling) and anticonvulsant medication (to prevent seizures) may be given. When your condition stabilizes, you’ll be transferred to a regular room where you’ll begin to increase your activity level.

The length of the hospital stay varies, from only 2-3 days or 2 weeks depending on the surgery and any complications. When released from the hospital, you’ll be given discharge instructions.

What is recovery like?

After surgery, pain may be managed with narcotic medication. Fatigue is common after surgery. Gradually return to your normal activities. Gentle stretches for the neck may be advised. Walking is encouraged; start with short walks and gradually increase the distance. Wait to participate in other forms of exercise until discussed with your surgeon.

You may shower and get your incision or sutures wet. Use mild baby shampoo with no harsh fragrances. Be careful not to let the water directly hit your incision. Gently clean any old, dried blood from the incision area.

Inspect your incision daily and checking for signs of infection, such as swelling, redness, yellow or green discharge, warm to the touch. Minimal swelling around your incision is expected.

Call you provider immediately if you experience any of the following:

  • A temperature that exceeds 101.5° F
  • An incision that shows signs of infection, such as redness, swelling, pain, or drainage.
  • If you are taking an anticonvulsant, and notice drowsiness, balance problems, or rashes.
  • Decreased alertness, increased drowsiness, weakness of arms or legs, increased headaches, vomiting, or severe neck pain that prevents lowering your chin to your chest.

You will be given a follow-up appointment 10 to 14 days after surgery. The recovery time varies from 1 to 4 weeks depending on the underlying disease being treated and your general health. Full recovery may take up to 8 weeks. Walking is a good way to begin increasing your activity level. Do not overextend yourself, especially if you are continuing treatment with radiation or chemotherapy. Ask your surgeon when you can expect to return to work.

What are the risks of a craniotomy?

No surgery is without risks. General complications can include:

  • Blood clots
  • Infection
  • Bleeding 
  • Reactions to anesthesia

Specific complications related to the craniotomy may include stroke, seizures, swelling of the brain, nerve damage, and CSF leak.