A craniotomy is a surgical procedure consisting in cutting part of the cranial cavity in order to create a small bone flap allowing access to the brain. Craniotomy is thus performed in various pathologies requiring direct access to the brain or decompression of the cerebral area.

A craniotomy, sometimes called a craniectomy, is a surgical procedure that involves cutting off the skull in order to remove a small part of it. This window, called the bone flap, provides access to the brain and / or releases intracranial pressure in the event of intracranial hypertension.

Depending on its indication, the craniotomy can be performed urgently or on a scheduled basis.

It takes place under general anesthesia, or in certain cases of tumors located on the cerebral areas of speech, under local anesthesia.

On the previously shaved and disinfected head, the neurosurgeon begins by peeling off part of the skin. He then proceeds to the craniotomy, which depending on the indications and the area of ​​the brain to be treated can be either bifrontal (so-called Kjellberg craniotomy, the flap is at the front of the skull, above the forehead) or fronto-temporo-parieto. occipital or hemispherical (or hemicraniectomy, the flap is on top of the skull). Using a specific instrument, he will cut a bone flap, the size of which is defined according to the indication for the intervention.

The surgeon then makes an incision in the membrane that covers the brain (dura), then separates it slightly, allowing him direct access to the brain.

Once the act of the intervention has been carried out (removal of a brain tumor, evacuation of a hematoma), the dura is stitched up, the bone flap is put back in place and fixed by means of small screws and plates, and the scalp incision closed with stitches or staples.

When the edema in the brain is very important, it may be necessary to do a so-called decompressive craniotomy in order to limit or fight against intracranial hypertension (HTIC). The bone flap is then not put back in place immediately. This so-called decompressive component will make it possible to increase the volume of the cranial box and thus lower intracranial pressure and improve cerebral perfusion (blood circulation). After regression of the edema, the flap is put back in place.

Craniotomy can be performed in different situations or pathologies requiring access to the brain, or to create an opening in order to release intracranial pressure. It can therefore be carried out:

• to surgically remove certain brain tumors. Thus, we have recourse to craniotomy for very large tumors of the pituitary gland that cannot be removed by transsphenoidal surgery;
• in some cases of ischemic stroke causing nonabsorbable edema of the brain (decompressive craniotomy);
• in certain cases of head trauma to surgically evacuate an acute extra-dural or sub-dural hematoma which may cause hemorrhage;
• in certain cases of head trauma resulting in intracranial hypertension refractory to medical treatment (decompressive craniotomy);
• to drain an abscess from the brain;
• to eliminate an arteriovenous malformation (AVM).

Operative suites

The patient is closely monitored, including a brain scan 24 hours after the operation.

Complete healing and solidification of the skull will be obtained after 6 weeks. The strength of the skull will be the same as before the surgery, but due to bone scarring, the skull may be slightly irregular.

The risks

Craniotomy is a heavy process, not without risks. Some of these risks are early:

• blood loss ;
• lesions of cerebral structures leading to cognitive or neurological disorders;
• a herniation of the brain through the craniectomy opening (in case of decompressive craniectomy);
• an infection.

Others are late:

• post-traumatic hydrocephalus due to impaired circulation of cerebrospinal fluid;
• a trepan syndrome (“sinking skin flap syndrome”) associating headaches, irritability, concentration and memory disorders, mood disorders, the appearance of a new neurological deficit

In some situations, such as a bone infection, the bone flap may not be able to be put back in place. A few months after the operation, we can then resort to a cranioplasty. This reconstructive surgery consists of placing a synthetic flap or a custom-made prosthesis to restore the skull to its initial shape.