A craniotomy is a surgery in which a portion of the skull’s bone is removed to access the brain. The bone flap, which is a portion of the bone, is temporarily removed with the aid of specialised equipment. After the brain surgery, the bone flap is reinstalled. In cases where the bone area is not restored, the procedure is called craniectomy.
Importance of craniotomy
Craniotomy surgeries range in intricacy and size–burr holes are smaller craniotomies, while ‘keyhole’ craniotomies are slightly larger holes. Instruments can be precisely positioned through holes using image-guided computers or stereotactic frames. For minimally invasive operations, keyholes and burr holes are employed to: (1) Open the ventricle with a shunt to discharge cerebrospinal fluid to treat conditions like hydrocephalus, (2) Place a deep brain stimulator in, (3) Extract a sample of tissue cells from the monitor (needle biopsy) (4) Remove a blood clot or hematoma aspiration, and (5) Remove malignancies by inserting an endoscope.
Large craniotomy operations are performed to allow the brain to decompress, or enlarge following a head injury or stroke, even though most skull holes are kept as small as possible. Months after healing, the bone flap is replaced after being frozen, which is called cranioplasty.
Diagnosing brain tumour
Procedures used to diagnose brain disorders include:
- Magnetic Resonance Imaging (MRI): The MRI is a large cylindrical machine that produces a powerful magnetic field in conjunction with radio waves around the patient. The waves emit complex data to a computer that receives these signals, processes them, and then produces a 2D image of the body part or organ under examination. When studying organs or soft tissue, MRI may be elected instead of CT scans, as it is superior at distinguishing between normal and diseased soft tissue. There are various applications of MRI technology used for a range of evaluations like magnetic resonance angiography (MRA) magnetic resonance spectroscopy (MRS) and functional magnetic resonance imaging (fMRI) to check for various conditions like aneurisms, disorders, coma, multiple sclerosis and stroke.
- Cerebral arteriogram: Angiograms, which are also called arteriograms, are X-rays of the blood vessels. It is used to check for blood vessel alterations like: (a) Blood vessel ballooning (aneurysm) (b) Blockages and (c) Blood vessel Narrowing (stenosis). Your doctor places a catheter inside a large blood artery from the groin or arm and administers contrast dye to perform an arteriogram to help the doctor better view the blood vessels on the X-ray image. An arteriogram shows the arteries of the heart, brain, kidneys, legs, and other organs. Using a cerebral arteriogram, one can examine the blood arteries in the head, neck, and brain. After that, X-rays are taken to view the brain’s arteries, veins, capillaries, and blood flow.
- Computed tomography (CT) scan: Brain computed tomography uses unique X-ray measurements to produce images of the specific brain area. The scans can give additional information regarding brain architecture and tissues than ordinary head X-rays, hence providing more information regarding brain conditions or injuries. During the procedure, an X-ray beam goes around the head in a circle, providing for multiple views inside the skull. The scan is transmitted to a computer, which analyses the data and shows it on a monitor in a 2D format. CT scans can be performed with or without a chemical dye or “contrast” that enhances the visibility of the organ or tissue under study. Prior to contrast examinations, you may be required to fast for a period of time. Your doctor will inform you about this before the operation.
- Electroencephalogram (EEG): An EEG is a test that identifies abnormalities in your brain waves or electrical brain activity. Small metal discs with tiny wires are adhered to the scalp during the operation. The electrodes detect the minute electrical charges generated by brain cell activity. The amplified charges are displayed as a graph on a computer screen or as a recording that may be printed on paper. Your physician will then interpret the results. In addition to focusing on the fundamental waveform, he or she analyses transient energy surges and responses to stimuli, such as flashing lights.
- Positron emission tomography (PET) scan: PET combines nuclear medicine with biochemical analysis to help visualise the biochemical changes occurring in the system. The technology is different from other tests as it investigates the metabolism of a specific tissue or organ, evaluating the physiology or functionality, structure, and biochemical characteristics of the organ or tissue. Other nuclear medicine tests measure the concentration of radioactive material in a particular area of a body tissue to assess that tissue’s function. PET is used in patients with cancer, brain, or heart disorders. During the procedure, a small amount of a radioactive substance is used to help analyse the tissue being studied. As a result, PET may be able to identify the beginning of a disease process in an organ or tissue before other imaging procedures like CT scan or MRI can detect structural changes associated with the disease.
- X-ray of the skull: X-rays create images of the skull by using electromagnetic energy rays. It is performed for a variety of purposes, including the diagnosis of malignancies, an infection, to detect foreign objects in the body, and bone fractures. X-rays penetrate body tissues and is captured on treated plates like a camera film. It creates a ‘negative’ type of image. Different body parts allow differing quantities of X-ray beams to pass through during X-ray examination. Thus, the whiter the body part appears on film, like the bone, the more solid is the structure. X-rays are used to examine the areas of skull for injuries, tumours or other issues of the brain and skull.
Inquire with your neurosurgeon the location of the skin incision and the extent of the bone removal. The following are diverse types of craniotomy surgeries:
Extended bifrontal cranium: It is a common skull-base technique which targets malignancies towards the front of the cerebrum. The bone that defines the orbits and the forehead is removed during an extended bifrontal craniotomy by making an incision in the scalp behind the hairline. By temporarily removing this bone, surgeons can operate in the region just behind and between the eyes without needing to touch the brain. After the procedure, the bone is replaced. The type of bifrontal craniotomy is often reserved for tumours that are not amenable to excision by minimally invasive techniques due to their anatomy, potential pathology, or surgical objectives. Meningiomas, esthesioneuroblastomas, and malignant skull base tumours are among the tumour types that can be treated with the extended bifrontal craniotomy.
Supra-orbit Craniotomy: Supra-orbital ‘eyebrow’ craniotomy is a minimally invasive surgery that may be preferred over an open craniotomy for quicker healing with minimal scarring. Specialists may use supra-orbital craniotomy operation to remove brain tumours. Neurosurgeons perform this procedure by making a tiny incision within the brow to access tumours in the front area surrounding the pituitary gland, which is located further in the brain behind the nose and eyes. The method is employed in place of endonasal endoscopic surgery when the tumour is particularly large or close to the optic nerves or major arteries. Surgeons also elect the type of surgery to treat Rathke’s cleft cysts, skull base tumours, and some pituitary tumours.
Retrosignal or retrosigmoid craniotomy: It is a minimally invasive surgical method known as a ‘keyhole’ craniotomy or retro-sigmoid craniotomy to remove brain tumours. Through a little incision behind the ear and with access to the cerebellum and brainstem, this surgery allows for the excision of skull base tumours. This method may be used by neurosurgeons to access malignancies such as meningiomas, auditory neuromas (vestibular schwannomas), tumours of the skull base, and metastatic brain cancers. Benefits of ‘keyhole’ craniotomies include quicker recovery times, less scarring, and less post-operative pain compared to open craniotomies.
Occipital-zygomatic Craniotomy: In many instances, targeting challenging tumours and aneurysms traditionally involves a skull base procedure called an orbitozygomatic craniotomy. An incision is made behind the hairline in the scalp to perform an orbitozygomatic craniotomy, which entails removing the bone that defines the contour of the orbit and cheek. This procedure is typically done for lesions that are too complex to be removed by other less invasive methods. By temporarily removing this bone, doctors can access the brain’s most intricate regions while limiting serious brain injury. At the conclusion of operation, the bone is replaced. Conditions like meningiomas, pituitary tumours, and craniopharyngiomas can be treated with an orbitozygomatic craniotomy.
Translabyrinth craniotomy: During the procedure, the mastoid bone and some of the inner ear bones are removed after making an incision in the head below the ear–especially, the semi-circular canals containing balance receptors. Next, the surgeon locates the tumour and removes it, or as much of it as is possible without endangering the brain severely. The technique is frequently used for the excision of acoustic neuromas when there is no functional hearing or when hearing must be sacrificed. The semi-circular canals of the ear are removed during the translabyrinthine craniotomy to reach the tumour. The removal of the semi-circular canals results in total hearing loss. With the translabyrinthine craniotomy, hearing is lost, but there may be a lower chance of facial nerve damage.
Awake craniotomies: When a damaged area is close to vital speech regions, awake craniotomies are carried out. Following the bone opening, the patient is awakened to assist the surgeon in identifying regions of concern. While you read or speak, a probe is positioned on the surface of your brain. This procedure, known as brain mapping, helps the surgeon avoid and protect your speech skills by identifying the specific brain regions that are specific to you.
Frontotemporal (pteronial) craniotomy: A frontotemporal or pteronial craniotomy surgery entails the removal of a portion of the pterion. To gain access to various sections of the brain, your surgeon creates an incision behind your hairline.
Endoscopic craniotomy: Endoscopic craniotomy is a type of craniotomy, which entails making a tiny incision in the skull and inserting a lighted scope with a camera into the brain.
Aneurysm cutting: A surgical technique and a type of craniotomy. The technique may be elected in cases where the cerebral aneurysm is bulging, or there is a weak spot in the wall of a brain artery that causes an abnormal ballooning, which is known as an intracranial aneurysm or brain aneurysm. There is a chance that the aneurysm will rupture because of the weak spot in the artery wall. A metal clip positioned over the “neck” of the aneurysm separates it from the rest of the vascular system and prevents rupture by obstructing blood flow.
Craniectomy: A related technique, during which the specialist removes or replaces a part of the skull permanently during a subsequent operation once the swelling has subsided.
Preparation before the craniotomy operation
The doctor orders diagnostic assessments a few days prior to the surgery to help patients get ready for it. Diagnostics performed include chest X-rays, blood tests, electrocardiograms, and brain scans by CT, MRI, or PET. Patients are advised to not consume anti-inflammatory drugs and blood thinners for about a week before the surgery. To reduce stress and/or prevent procedure edoema, infection, or seizures following surgery, the specialists may prescribe meds to be taken before the craniotomy operation. Prior to surgery, the patient should refrain from chewing tobacco, smoking, and alcohol, as they may lead to complications and slow the healing process. Doctors advise fasting for at least a day prior to the surgery. The patient’s head is prepped and removed of hair around the surgery area. Just before the surgery, the surgeon administers general anaesthesia to sedate the patient. In contrast, general anaesthesia is administered when a patient is having an awake craniotomy–the patient will be awake for some of the surgery. The doctors may administer a local anaesthetic in the surgical area during stereotaxy.
During the procedure
A 3-pin skull fixation device is used to fix the patient’s head in position once the anaesthetic takes effect. The cerebrospinal fluid that is secreted in the brain and travels via the spinal column is then removed using a drain that is implanted in the lower back. During surgery, draining the spinal fluid helps release the brain from pressure. The surgeon makes an incision on the skin after the scalp has been cleaned with an antiseptic. The incision may be made above the ear and eye or around the occipital bone at the base of the skull. The scalp’s skin and tissues are pulled back revealing the skull. The skull is then punctured with tiny holes using a high-speed drill, and a flap is cut out through the holes using a bone saw. The brain tissues are exposed where the bone flap was removed, allowing the surgeon to commence surgery or conduct an evaluation. After the surgery, the bone flap is repositioned and secured with wires, screws, and plates. To remove fluid and blood from the surgical site, the surgeon may insert a drain under the skin. The drain can remain in place for a day or two. The muscles and skin are sewed back together, and the incision is covered with a bandage or dressing. It can take up to six hours to complete the process from administering the anaesthetic to the anaesthesia to wearing off after surgery.
After the procedure
The patient is shifted to the recovery area and closely monitored for vitals, which include temperature, blood pressure, heart rate, and breathing tubes, catheters, and a drip. After the patient awakens, they are subsequently moved to the ICU for additional neurological observation. To check for post-operative issues, the surgeons ask the patient to move their fingers, toes, hands, and legs. After a craniotomy, nausea and headaches are frequent side effects. Seizures and brain edoema after surgery can be controlled with medications. If everything goes according to plan, the patient is moved to a standard hospital room where, depending on the type of brain surgery and any complications, they may remain for up to two weeks. The patient is sent home with instructions to follow and is asked to schedule a visit with their doctor to have any stitches or staples removed in a week.
Craniotomy surgery cost in India
In India, craniotomy surgery might cost anything from Rs 3,25,000. The craniotomy surgery cost varies between hospitals in India. A craniotomy surgery in Ties I cities will be more expensive than outside the cities. If you are from outside the country, there will be additional craniotomy costs like lodging and local transportation in addition to the cost of craniotomy surgery. The patient stay in the hospital following surgery for seven days, followed by ten days in a hotel to allow for full recovery. Thus, the total cost of craniotomy in India can exceed Rs 5,00,000.