Craniotomy

Introduction

A craniotomy is one of the most common brain operations. The word means “cutting into the skull,” and that is what the procedure involves: the surgeon temporarily removes a piece of bone from the skull to reach the brain underneath. Once the surgery on the brain is finished, the bone is put back in place and the scalp is closed.

If you or a family member has been told that a craniotomy is needed, the reasons can feel frightening — a brain tumour, a bleed, an aneurysm, severe head injury, epilepsy, or another condition affecting the brain. The operation itself, however, is a well-established procedure that neurosurgeons perform every day. Modern imaging, microsurgical techniques, and intraoperative monitoring have made it far safer and more precise than it was a generation ago.

This article explains what a craniotomy is, why it is done, the different types and approaches your neurosurgeon may discuss with you, how to prepare, what happens during the operation, and what recovery typically looks like. It is written for patients who already have a diagnosis and are now planning the next phase of care, and for the family members supporting them.

What Is a Craniotomy?

A craniotomy is a planned surgical opening of the skull to give the neurosurgeon direct access to the brain, its coverings (the meninges), or the blood vessels around it. The piece of bone that is removed is called a bone flap. At the end of the operation, the bone flap is fixed back in place using small titanium plates and screws, or sometimes special biocompatible plates that hold the bone while it heals.

A related procedure, called a craniectomy, is the same opening of the skull but the bone is not replaced at the end — usually because the brain is swelling and needs room to expand. The bone may be replaced later in a separate operation called a cranioplasty. When you read about “decompressive surgery” for severe head injury or large strokes, it is usually a craniectomy.

Craniotomy is not a single operation but a category. The size, shape, and location of the bone flap depend entirely on what part of the brain needs to be reached and why. A small keyhole opening behind the ear is a craniotomy. A larger opening over the side of the head to remove a tumour is also a craniotomy. The principle is the same; the details differ.

Why Is a Craniotomy Performed?

Neurosurgeons perform craniotomies for many reasons. Some of the most common include:

• Brain tumours. Removing or sampling (biopsying) a tumour in the brain or its coverings, such as a glioma, meningioma, or metastasis from a cancer elsewhere in the body.
• Bleeding inside the skull. Evacuating a haemorrhage caused by trauma, a ruptured aneurysm, or a stroke. Examples include subdural haematoma, epidural haematoma, and intracerebral haemorrhage.
• Aneurysms. Placing a small metal clip across the neck of a brain aneurysm to prevent it from bleeding. (Many aneurysms today are treated through the blood vessels with coiling instead, but clipping through a craniotomy remains an option for certain aneurysms.)
• Arteriovenous malformations (AVMs) and other abnormal blood vessel tangles.
• Severe traumatic brain injury, particularly to remove blood clots or relieve dangerous pressure inside the skull.
• Epilepsy surgery, in selected patients whose seizures do not respond to medication and whose seizure focus can be identified and safely removed.
• Infections such as a brain abscess that needs to be drained.
• Hydrocephalus in some situations, although this is more often treated with a shunt or endoscopic procedure.
• Skull base lesions at the bottom of the brain, including some tumours of the pituitary region, acoustic neuromas, and meningiomas.
• Movement disorder surgery, including deep brain stimulation lead placement (a smaller craniotomy through a burr hole).

The decision to operate depends on the diagnosis, the location of the problem, your overall health, and what alternatives are available. For some conditions, surgery is clearly the best option; for others, it is one of several reasonable paths, and the choice rests on a careful conversation with your neurosurgical team.

Who Is a Candidate?

Whether a craniotomy is the right operation for a specific person depends on several factors that the surgical team weighs together:

• The diagnosis and its location. Some lesions are clearly reachable through a safe corridor in the brain; others sit in areas where surgery carries higher risk and may not be the first choice.
• Symptoms and how quickly they are changing. A rapidly worsening neurological problem — new weakness, difficulty speaking, drowsiness, repeated seizures — often pushes towards surgery more urgently.
• Overall health. Heart, lung, kidney, and clotting function all matter for a major operation under general anaesthesia. The anaesthetic team reviews these carefully.
• Age and frailty. Age alone rarely rules out surgery, but the physiological reserve to recover does matter.
• Goals of care. Especially in advanced cancer, the goal may be to relieve symptoms, obtain a tissue diagnosis, or extend good-quality time, rather than to cure. The plan should match the goal.

People taking blood-thinning medications, with active infection, or with poorly controlled diabetes or blood pressure may need their condition optimised before surgery. The team will often coordinate with cardiology, anaesthesia, and other specialists in advance.

Alternatives to Craniotomy

Craniotomy is one of several ways to address problems in the brain. Depending on the underlying condition, alternatives may include:

• Endovascular (catheter-based) treatment. Many aneurysms and some AVMs are now treated by passing a thin catheter through a blood vessel in the groin or wrist up to the brain, and either placing coils, a stent, or a flow-diverter inside the abnormal vessel. For suitable aneurysms, this avoids opening the skull.
• Stereotactic radiosurgery. Focused beams of radiation delivered in a single session or a small number of sessions can treat certain brain tumours, metastases, and AVMs without an incision. Gamma Knife and CyberKnife are well-known forms.
• Endoscopic and transnasal surgery. Pituitary tumours and some skull-base lesions can be reached through the nose using an endoscope, avoiding a traditional craniotomy.
• Laser interstitial thermal therapy (LITT). A laser fibre placed through a small skull opening can heat and destroy certain tumours or seizure foci. Availability varies by centre.
• Burr-hole drainage. Some chronic subdural haematomas can be drained through one or two small holes in the skull, without lifting a full bone flap.
• Medical management alone. For some tumours that are slow-growing or in very high-risk locations, careful observation with serial imaging may be the safer course. For some bleeds, blood pressure control and time are enough.
• Chemotherapy and targeted therapy. For certain cancers and lymphomas of the brain, drug treatment plays a major or even primary role.

Whether any of these alternatives is suitable depends on the diagnosis, location, size, and your overall situation. Many centres take complex cases to a multidisciplinary meeting where neurosurgeons, neurologists, oncologists, radiation oncologists, and interventional neuroradiologists review the imaging together and agree on a recommendation.

Types and Surgical Approaches

The same word — craniotomy — covers many different operations. Your neurosurgeon will plan the approach based on where the problem is and what needs to be done.

Standard (open) craniotomy

The traditional approach. The surgeon makes a curved incision in the scalp, lifts a flap of bone using a high-speed drill, opens the dura (the tough membrane around the brain), performs the necessary work, closes the dura, replaces the bone flap, and closes the scalp. The size and position depend on the target — frontal, temporal, parietal, occipital, or at the base of the skull.

Keyhole and minimally invasive craniotomy

A smaller, carefully planned opening — sometimes only a few centimetres — used to reach a specific target through a natural corridor in the brain. The eyebrow approach (supraorbital), the retrosigmoid keyhole approach behind the ear, and small parasagittal openings are examples. Keyhole surgery is not always “better” than a standard approach; it is suitable when the lesion is well-positioned for it. Major neurosurgical societies emphasise that the approach should be chosen to fit the problem, not the other way around.

Awake craniotomy

For tumours or seizure foci near regions of the brain that control speech, movement, or other vital functions, the operation may be performed with the patient awake for part of it. The scalp and skull do not have pain sensors in the way the skin elsewhere does, so with local anaesthetic and careful sedation, this is well tolerated. While the patient is awake, the surgeon uses gentle electrical stimulation to map which areas of the brain control which functions, and avoids removing tissue that produces a change in speech, movement, or other tested abilities. Awake craniotomy is a specialised technique used by centres with the appropriate team and experience.

Stereotactic and image-guided craniotomy

Most modern craniotomies use some form of image guidance — a system that tracks the surgeon’s instruments in real time on the preoperative MRI or CT scan, similar to a GPS for the brain. This helps plan the safest entry point and corridor. In stereotactic biopsy, a small opening is used and a needle is precisely directed to a deep target to obtain a tissue sample.

Skull base craniotomy

Approaches to the bottom of the skull, where the brain meets the face, ears, and spinal cord, require specialised techniques because important nerves and blood vessels are tightly packed in this region. These operations are often performed jointly by neurosurgeons and ENT (ear, nose, and throat) surgeons.

Decompressive craniectomy

When the brain is swelling dangerously after a severe injury or large stroke, the bone flap may be left out at the end of surgery to give the brain room to swell without being crushed. The skin is closed over the brain. Once the swelling has settled — usually weeks to months later — the bone (or a custom-made plate) is replaced in a separate operation called cranioplasty.

Preparing for a Craniotomy

Once a craniotomy is planned, several steps usually happen in the days or weeks before the operation.

Investigations

You can expect detailed imaging, usually an MRI of the brain with contrast, sometimes a CT scan, and sometimes specialised scans such as functional MRI (to map important areas of the brain), diffusion tensor imaging (to map white-matter tracts), or angiography (to map blood vessels). Blood tests, an ECG, and a chest X-ray are common. If a tumour is suspected, additional tests may look for cancer elsewhere in the body.

Anaesthesia review

An anaesthetist will meet you to review your health, medications, allergies, and previous experience with anaesthesia. They will explain how you will be put to sleep, what monitoring will be used, and how pain will be managed.

Medication adjustments

Blood thinners (such as warfarin, aspirin, clopidogrel, or newer oral anticoagulants) often need to be paused or replaced for a period before surgery to reduce bleeding risk. Diabetes medications, blood pressure medications, and steroids are adjusted according to the team’s protocol. Do not stop or change any medication on your own — always follow the team’s instructions.

Hair and skin

You will usually be asked to wash your hair the evening before or the morning of surgery. Modern practice in most centres is to shave only a narrow strip along the planned incision, or sometimes no hair at all, rather than shaving the whole head.

Fasting

You will be told when to stop eating and drinking before surgery — typically no solid food from the night before, and clear fluids only up to a few hours before, according to anaesthetic guidance.

Consent and questions

The surgeon will explain the operation, its risks, alternatives, and expected benefits, and ask you to sign a consent form. This is a good time to ask anything that is unclear — bring a family member if it helps, and write your questions down beforehand. Reasonable questions include: What is the goal of the operation? How much of the lesion do you expect to remove? What are the most likely complications in my case? What does recovery usually look like? Who will be in the operating room?

Practical preparation at home

Arrange help at home for the first few weeks. You will not be able to drive immediately after surgery, and lifting and bending will be limited. Prepare easy meals, organise medications, and identify who will accompany you to follow-up appointments.

What Happens During a Craniotomy

The exact steps depend on the operation, but the general sequence is similar.

In the operating room

You will be brought into the operating room and connected to monitors that track your heart rate, blood pressure, oxygen, and breathing. An intravenous line is placed for medications and fluids. For most craniotomies, general anaesthesia is used — you will be asleep, with a breathing tube placed once you are unconscious. For awake craniotomy, sedation and local anaesthesia are used, and the team will have already explained how the awake parts will feel.

Positioning

Your head is fixed in a clamp (often called a Mayfield head holder) using small pins that grip the skull. This keeps the head completely still during surgery and allows the navigation system to track precisely.

Skin and bone

The surgeon marks the planned incision, often using the image-guidance system. The hair along the incision is shaved if needed, the skin is cleaned with antiseptic, and sterile drapes are placed. The scalp incision is made, the muscle and tissue are moved aside, and small holes (burr holes) are drilled in the skull. A specialised cutting tool connects these holes to lift the bone flap as a single piece, which is set aside on the sterile trolley to be replaced later.

Opening the dura and operating on the brain

The dura is carefully opened to expose the brain. Using an operating microscope or, in some centres, an exoscope, and very fine instruments, the surgeon performs the planned work — removing a tumour, evacuating a clot, clipping an aneurysm, or whatever the operation requires. Modern operations often use neuronavigation, intraoperative neuromonitoring (which watches the function of nerves and brain pathways in real time), and sometimes intraoperative imaging or ultrasound.

Closing

Once the work is done and bleeding is controlled, the dura is closed with stitches, the bone flap is fixed back in place with small titanium plates and screws, and the scalp is closed in layers. A small drain may be left under the skin for a day or two. A dressing is applied.

Duration

The time in the operating room varies widely — from around two hours for a straightforward procedure to eight hours or more for a complex tumour or skull base operation. The actual time on the brain is usually shorter than the total operating room time, because positioning, anaesthesia, opening, and closing all take time.

Recovery and Healing

Recovery from a craniotomy happens in phases. How long each phase lasts depends on what was treated, how much of it could be addressed, your starting condition, and your overall health.

Immediately after surgery

You will wake up in the recovery area and then usually be transferred to a neurosurgical intensive care unit (ICU) or a high-dependency unit for the first 24 to 48 hours. Nurses and doctors will check your level of alertness, pupil reactions, strength, and speech at regular intervals — this is normal and important. A CT scan is often performed within the first day to check for bleeding or swelling.

It is common to have a headache, some nausea, a sore throat from the breathing tube, and tiredness. Pain is usually managed with paracetamol, mild opioids, and other medications; the team avoids drugs that interfere with the neurological examination. Many people are surprised at how manageable the pain is — the scalp is the most painful part, not the brain itself, which has no pain sensors.

The hospital stay

Most patients move from the ICU to a regular neurosurgical ward after one or two days and stay in hospital for a total of about three to seven days, though this varies. Drains and the urinary catheter are removed when appropriate. Physiotherapy often begins early to get you out of bed and walking. Stitches or staples in the scalp are usually removed about 7 to 14 days after surgery, depending on the closure technique.

The first weeks at home

Going home does not mean recovery is complete. Most people feel surprisingly tired for several weeks — the brain uses an enormous amount of energy to heal, and fatigue is one of the most common and underestimated symptoms. Short walks, regular sleep, and gradual increase in activity are typical recommendations.

You will be asked to avoid:

• Heavy lifting (often more than 5 kilograms) for several weeks
• Strenuous exercise, contact sports, and swimming until cleared
• Driving until the surgeon (and, in some cases, a doctor reviewing seizure risk) confirms it is safe
• Alcohol while taking certain medications
• Air travel for a period your team will specify, particularly after operations involving air inside the skull

The scalp wound usually heals well, but the area may feel numb, tingly, or oddly sensitive for months. A small lump or ridge over the bone plates is normal. Hair regrows over the incision in the weeks after surgery.

The longer recovery

By six weeks, many people feel substantially better, though fatigue may persist. By three months, most ordinary activities have been resumed. Full recovery — including return to demanding mental work, complex tasks, and high-level physical activity — can take six months to a year, and longer if the brain was already affected by the underlying condition.

If the operation was for a tumour, recovery often happens alongside further treatment such as radiotherapy or chemotherapy. If the operation was for epilepsy, the team will continue to adjust seizure medications over time. If the operation was for a bleed or stroke, neurorehabilitation — physiotherapy, occupational therapy, speech therapy — may continue for many months.

Rehabilitation

Many patients benefit from structured rehabilitation after a craniotomy, particularly when neurological symptoms (weakness, speech changes, balance problems, vision changes, swallowing difficulties, or thinking and memory changes) are present. Rehabilitation is usually multidisciplinary — physiotherapists, occupational therapists, speech and language therapists, neuropsychologists, and rehabilitation physicians working together. Goals are set in stages, and progress is reviewed regularly.

Risks and Complications

A craniotomy is major surgery on the brain, and although it is performed safely every day, every patient should understand the possible risks. Major neurosurgical societies group complications in the following categories:

General surgical risks

• Bleeding and the need for blood transfusion
• Infection of the wound, the bone, the meninges (meningitis), or the brain (cerebritis or abscess)
• Reactions to anaesthesia
• Blood clots in the legs (deep vein thrombosis) or lungs (pulmonary embolism)
• Pneumonia and other chest complications

Brain-specific risks

• New neurological deficits — weakness, numbness, speech difficulties, vision problems, or balance problems — depending on the area operated on. Some are temporary; some may be permanent.
• Seizures, either as a one-time event in the recovery period or as a longer-term issue, particularly after operations on the cortex. Anti-seizure medication is often given preventively for a period.
• Brain swelling in the days after surgery, which may require additional treatment.
• Cerebrospinal fluid (CSF) leak from the wound or, in skull base operations, through the nose or ear. This may need additional treatment.
• Hydrocephalus — build-up of fluid in the brain — which may require a drain or shunt.
• Stroke, if a blood vessel is injured or blocked during surgery.
• Cognitive changes — difficulties with memory, attention, problem-solving, or mood — that may improve over time but sometimes persist.

Wound and bone-related issues

• Slow wound healing, particularly in patients who have had previous radiotherapy or who take steroids
• Issues with the bone flap, including resorption (the bone slowly thinning over time) or, rarely, the need to remove and replace the bone flap if infection develops
• Persistent scalp numbness or sensitivity

The overall risk of major, permanent complications depends heavily on the reason for surgery, the location, and your starting condition. Operations for a small, well-positioned tumour in a non-eloquent area of the brain carry very different risks than emergency surgery for a large bleed in a critically ill patient. Your surgeon will be able to give you a personalised picture based on your imaging and your circumstances.

Life After a Craniotomy

Life after a craniotomy depends, more than anything, on the condition that led to the operation. For some people, the operation is curative — an aneurysm clipped, a benign tumour fully removed, a bleed evacuated — and life largely returns to what it was before. For others, the operation is one step in a longer journey of treatment and adjustment.

Returning to work

Many people return to work between six weeks and three months after surgery, with sedentary jobs returning sooner than physically demanding ones. A graded return — reduced hours initially, building back up — is often helpful. For roles involving heavy machinery, heights, or driving, clearance from the medical team is needed.

Driving

Driving is restricted after a craniotomy. The duration of the restriction depends on the reason for surgery, whether there have been seizures, and local regulations. Your team will tell you when it is safe and legal to resume driving.

Mood and emotion

It is common to feel emotional, anxious, or low in the weeks and months after brain surgery — both as a reaction to a frightening experience and because the brain itself may take time to settle. Talking openly with the team, family, and where helpful a counsellor or psychologist is part of recovery, not a sign of weakness.

Cognitive recovery

Many people notice that thinking, concentration, and memory feel slower than before for a while. This often improves over months. Neuropsychological assessment can help characterise any specific difficulties and guide rehabilitation.

Follow-up

You will have regular follow-up with the neurosurgical team, often with repeat MRI or CT scans. If the operation was for a tumour, follow-up may also involve oncology, radiation oncology, and pathology review of the tissue removed. If it was for vascular disease, follow-up imaging of the blood vessels may continue for years.

Helmet use and physical activity

Once the bone flap has healed in place (usually within a few months), the skull regains good strength. After a craniectomy where the bone is still missing, a protective helmet is often worn until cranioplasty. Returning to contact sports, martial arts, and similar activities should be discussed individually with the surgeon.

Craniotomy in Children

Children undergo craniotomies for many of the same reasons as adults — brain tumours, congenital malformations, epilepsy that does not respond to medication, traumatic injury, and vascular problems — but their care has important differences.

Paediatric neurosurgery is usually performed in centres with dedicated paediatric neurosurgical, anaesthetic, intensive care, and rehabilitation teams. The skull of a child is more flexible than an adult’s, and the brain is still developing, which influences both the surgical technique and the patterns of recovery. Children often recover function more fully than adults after the same operation, but they also need careful follow-up of growth, development, learning, and hormones, especially after operations near the base of the brain.

For parents, preparation includes age-appropriate explanation of what will happen, planning for time away from school, and arranging support for siblings. Hospitals with paediatric units usually have child life specialists or play therapists who help children understand and cope with the experience. School re-entry is planned with the rehabilitation team and the school, sometimes with individualised support for learning needs that emerge after surgery.

Outcomes for children depend strongly on the underlying diagnosis. For benign tumours and epilepsy surgery in well-selected patients, results can be excellent. For more serious conditions, ongoing multidisciplinary follow-up over many years is the norm.

When to Seek Urgent Care After Surgery

After you go home, certain symptoms should prompt you to contact the team or seek emergency care. These include:

• A severe or rapidly worsening headache that is different from your usual post-operative headache
• New weakness, numbness, difficulty speaking, confusion, or drowsiness
• A seizure
• Repeated vomiting
• High fever or shaking chills
• Redness, swelling, increasing pain, or discharge from the wound
• Clear fluid leaking from the wound, nose, or ear
• Sudden vision changes
• Swelling of the leg, calf pain, sudden chest pain, or shortness of breath

The team will give you specific numbers to call. When in doubt, it is safer to be checked than to wait.

Frequently Asked Questions

Will my whole head be shaved?

Usually no. Most modern centres shave only a narrow strip along the planned incision, and sometimes nothing at all. The exact practice varies by surgeon and operation.

Will I have a visible scar?

Most craniotomy incisions are placed behind the hairline where possible, so once the hair regrows the scar is largely hidden. Skull base and some emergency operations may have more visible scars.

How painful is the operation?

The brain itself does not feel pain. The scalp and muscles do, so most of the post-operative pain comes from the incision. Modern pain management usually keeps this well controlled with paracetamol, mild opioids, and other medications.

Will I feel the metal plates in my skull?

The titanium plates are very small and sit close to the bone. Most people do not feel them once healing is complete. They are designed to stay in place permanently and do not usually need to be removed.

Can I have an MRI scan after a craniotomy?

Yes. The titanium plates and screws used in modern craniotomies are MRI-compatible. Aneurysm clips made in recent decades are also generally MRI-safe, but the team always confirms the specific implant before scanning.

How soon can I fly?

This depends on the operation. Air in the skull after surgery can expand at altitude, so flying is usually avoided for a period that the team will specify — often several weeks. Always check before booking travel.

Will my hair grow back normally?

Hair usually regrows along the incision, although it may grow back finer or slightly differently for a while. A thin line of scar tissue along the incision is normal.

What is the difference between a craniotomy and a craniectomy?

In a craniotomy, the bone flap is replaced at the end of the operation. In a craniectomy, the bone is left out, usually to give the brain room to swell, and is replaced later in a separate procedure called cranioplasty.

Will I be able to think clearly again?

Many people notice slower thinking, more fatigue, and reduced concentration for weeks or months. For most, these improve substantially over time. Where difficulties persist, neuropsychological assessment and rehabilitation can help identify and work with the specific areas affected.

How do I choose where to have my craniotomy?

Reasonable things to look for include a neurosurgical team that regularly treats your specific condition, the presence of a multidisciplinary team (neuro-oncology, neuroradiology, neuro-anaesthesia, neuro-intensive care, and rehabilitation), modern imaging and intraoperative technology, and a clear explanation of the plan and the alternatives. Meeting the team and feeling that your questions are taken seriously matters too.

Conclusion

A craniotomy is a precise, well-established operation that allows surgeons to treat a wide range of conditions inside the skull. The specifics — the size of the opening, whether you are awake for part of it, what the surgeon does once the brain is exposed, and what recovery looks like — depend entirely on the reason for the operation.

For patients and families, the most useful preparation is to understand the goal of the surgery, the alternatives that were considered, the most likely risks in your situation, and what the first weeks and months after the operation will involve. Recovery takes time, and fatigue is often the most lasting symptom; rehabilitation, follow-up imaging, and ongoing support from the team are part of the journey rather than optional extras. With careful planning, modern technique, and a multidisciplinary team, most people come through a craniotomy and into the next phase of their care in better shape than they expected.