Craniotomy

A craniotomy is a major brain surgery where a surgeon temporarily removes part of your skull to access and treat problems inside your brain, then carefully replaces the bone before closing the incision.

Table of contents

• What is a Craniotomy?
• Conditions Treated by Craniotomy
• Types of Craniotomy
• How to Prepare for a Craniotomy
• What Happens During a Craniotomy
• Recovery After Craniotomy
• Risks and Complications

What is a Craniotomy?

A craniotomy is a surgical procedure where a neurosurgeon (a doctor who specializes in brain and nervous system surgery) temporarily removes a piece of your skull to reach the brain^[1][2]. The removed piece of bone is called a bone flap^[3]. After performing the necessary brain surgery, the surgeon replaces the bone flap and attaches it to the surrounding skull using small titanium plates and screws^[2][6].

This procedure is different from a craniectomy, where the piece of skull is not immediately put back into place after surgery^[2]. In a craniectomy, you may need a follow-up surgery called a cranioplasty weeks or months later to replace the missing part of your skull^[3][6].

Craniotomy has a long history. Trephination (drilling holes in the skull) has been found to be performed by prehistoric people as early as 1783 for various purposes^[3]. Modern craniotomy techniques evolved significantly in the 19th century with advancements in antisepsis and general anesthesia^[3].

Conditions Treated by Craniotomy

A craniotomy is used to treat many different brain problems^[1][2]. The most common conditions include:

• Brain tumors (growths in the brain that may be cancerous or non-cancerous)
• Blood clots in the brain
• Aneurysms (bulging blood vessels in the brain that can burst)
• Arteriovenous malformations (abnormal tangles of blood vessels)
• Bleeding in the brain
• Brain swelling caused by injury or stroke
• Epilepsy (a condition that causes repeated seizures)
• Brain infections or abscesses (pockets of pus)
• Skull fractures
• Tears in the dura mater (the tough covering over the brain)

Craniotomy can also be used to implant medical devices such as stimulators to treat movement disorders like Parkinson’s disease, or to place devices to monitor brain activity^[2][6][7].

Types of Craniotomy

There are several types of craniotomy procedures. The names usually describe where on the skull the surgeon removes the bone^[1][2]:

• Frontal craniotomy: The surgeon removes part of the front of the skull near your hairline
• Bifrontal craniotomy: Part of the front of the skull behind the hairline is removed, often used to treat brain aneurysms
• Supraorbital craniotomy: This removes an area of skull just above the eye socket, sometimes called an eyebrow craniotomy because the incision is hidden in the eyebrow^[1]
• Pterional (frontotemporal) craniotomy: The surgeon removes part of the skull on the side of the head, behind the temple, in front of and above the ear^[1][2]
• Parietal craniotomy: The opening is made in the top-middle and upper back of the skull
• Temporal craniotomy: Part of the skull next to your eyes and in front of your ear is removed
• Retrosigmoid (keyhole) craniotomy: A small incision in the area of the skull behind the ear^[2]
• Suboccipital craniotomy: The base of the skull, above the neck^[2]
• Orbitozygomatic craniotomy: Part of the skull near the eye socket and cheek

A keyhole craniotomy is a minimally invasive approach where surgeons make openings about the size of a dime, using smaller incisions and specialized techniques^[7]. Sometimes pterional keyhole craniotomy is performed, which removes a smaller area than the standard pterional approach^[1].

Advanced imaging and computer technology may be used to guide the surgeon during the procedure. This is called stereotactic craniotomy or image-guided craniotomy, where scans create a three-dimensional picture of the brain that acts like a roadmap or GPS for the surgeon^[6][7].

How to Prepare for a Craniotomy

Before your craniotomy surgery, you will meet with your surgeon who will carefully plan the procedure^[2]. Your surgeon will order several tests to assess your health and the reason for your surgery. These tests also help the anesthesiologist (the doctor who gives you medication to prevent pain during surgery) determine how much anesthetic to give during your procedure^[2].

Common tests before craniotomy include^[2]:

• Physical examination
• Blood tests
• Imaging tests such as MRI (magnetic resonance imaging), CT scan (computed tomography scan), PET scan (positron emission tomography), or angiography (imaging of blood vessels)

Your surgeon will give you specific instructions on how to prepare, which may include^[2]:

• Arriving on the day of surgery without eating or drinking (on an empty stomach)
• Stopping any blood-thinning medications three to 10 days before surgery
• Taking antibiotics, anticonvulsant medications (medicines to prevent seizures), or corticosteroids (medicines to reduce swelling) before the day of surgery

Your surgeon will discuss the results of your tests, explain the procedure, describe possible side effects, and tell you what to expect after surgery and during your healing time^[2]. If you have any questions about the surgery, ask your surgeon before the day of your procedure.

What Happens During a Craniotomy

A craniotomy is performed under general anesthesia, which means you will be asleep and will not feel any pain during the surgery^[2][5]. The procedure typically takes about two and a half hours, though this can vary^[5].

The general steps of a craniotomy include^[5][2]:

• Your head is positioned on a special headrest or may be clamped into place with a head pin fixing device to keep it still
• The hair on your scalp near the surgery site is shaved
• Your head is sterilized using iodine or alcohol to kill germs and reduce the risk of infection
• The surgeon makes an incision (cut) in your scalp
• Small holes called burr holes are drilled into the skull
• A special surgical saw called a craniotome is used to cut from one burr hole to the next, creating the removable bone flap^[5]
• The membrane covering the brain (dura mater) is opened
• The surgeon performs the necessary brain surgery, such as removing a tumor, repairing blood vessels, or removing a blood clot
• After the brain surgery is finished, the dura mater is closed
• The piece of skull is replaced and attached using titanium plates and screws, wire, or sutures
• A drain may be placed inside the brain to remove any excess blood from the surgery^[5]
• The muscle and skin are stitched up

In some cases, patients remain awake during parts of the surgery. This is done when the surgeon needs to test brain functions during the procedure. Patients may be asked to move their legs, recite the alphabet, or tell stories to make sure that brain functioning has not been affected^[11].

Recovery After Craniotomy

After your craniotomy, you can expect to be monitored closely by hospital staff, probably in the intensive care unit (ICU)^[5]. The breathing tube will remain in place until you have fully recovered from the anesthesia. Medical staff will watch your vital signs and neurological status and manage your pain^[5].

Most patients spend between three and seven days in the hospital, but specific recovery times vary^[2][11]. Some patients may need to go to a short-term rehabilitation center after leaving the hospital to help them learn to do tasks they need to do at home^[15].

Common experiences immediately after surgery:

• Headaches for a few days
• Feeling very tired or weak
• Numbness and shooting pains near the wound
• Swelling and bruising around the eyes
• Soreness at the incision sites
• Itching as the wound starts to heal

Pain medication is prescribed to relieve symptoms and help with healing^[11][15]. Medicines and ice packs can help with headaches, pain, swelling, and itching^[15].

Recovery timeline:

The initial recovery period, when you can manage basic activities at home, typically takes about one week^[16]. Full recovery, when you can return to all or most normal activities including work, driving, and physical exercise, can take one to two months^[2][16]. It is normal to feel very tired for several weeks after surgery^[15].

The stitches or staples holding your incisions together may dissolve on their own or will be removed in seven to 10 days^[15]. If your head was shaved, you may want to wear hats or scarves until your hair grows back^[15].

Recovery tips include^[15][18]:

• Rest when you feel tired and plan to take a nap every day
• Try to walk each day, gradually increasing the amount
• Bring your head up slowly after lying down to prevent headaches or dizziness
• Avoid heavy lifting until your doctor says it is okay
• Do not drive until your doctor approves
• Keep the surgery area clean and dry
• Take all prescribed medications as directed
• Attend all follow-up appointments
• Be patient with your recovery and avoid getting frustrated
• Get quality sleep to help your brain recover

Depending on the area of the brain that was involved in the surgery, some patients may require physical therapy to help with coordination, occupational therapy for daily activities, or speech therapy for communication skills^[5][2].

Recovery is highly individualized. In emergency cases, such as after head injury or brain hemorrhage, full recovery may take longer, sometimes over a year^[16]. Each person recovers at a different pace^[15].

Risks and Complications

As with any surgery, craniotomy carries risks. Brain surgery is complex and not without potential complications^[11]. Some risks are related to the specific location being operated on. For example, if the area of the brain that controls speech is operated on, then speech may be affected^[6][11].

General surgical risks include^[6]:

• Infection
• Bleeding
• Blood clots
• Infection of the lungs (pneumonia)
• Unstable blood pressure
• Risks of general anesthesia

Complications specific to brain surgery include^[6][4]:

• Brain swelling
• Seizures
• Muscle weakness
• Leakage of cerebrospinal fluid (the fluid that surrounds and cushions the brain)
• Surgery can damage healthy brain tissue, causing problems with walking, talking, or moving arms or legs
• Meningitis (infection of the membranes covering the brain), which occurs in about 0.8 to 1.5 percent of individuals undergoing craniotomy^[4]

Rare complications include:

• Memory problems
• Speech problems
• Paralysis
• Abnormal balance or coordination
• Coma

The risk for meningitis is independently associated with the use of steroids around the time of surgery and ventricular drainage (draining fluid from the brain)^[4]. At least 40 percent of patients undergoing craniotomy become susceptible to at least one infection^[4].

If left untreated, conditions requiring brain surgery can cause further damage to the brain. Pressure on the brain can be harmful as it forces the brain against the skull, causing damage and hampering the brain’s ability to function properly. This can lead to long-lasting brain damage or even death^[5].

The medical team vigilantly watches for any signs of complications in the days following the operation, which is critical for successful recovery^[5].