Craniotomy and cancer

ALSO KNOWN AS: Brain surgery

DEFINITION: Craniotomy is a surgical procedure in which an incision is made into the skull to gain access to the brain.

Cancers treated: Brain cancers such as glioma, astrocytoma, medulloblastoma, and ependymoma

Why performed: Craniotomy is performed for cerebral artery aneurysm clipping, arteriovenous malformation repair, increased intracranial pressure control, hematoma drainage, ventricular shunting, and abscess or tumor excision.

Patient preparation: Before surgery, the patient undergoes a computed tomography (CT) scan or magnetic resonance imaging (MRI) of the brain to determine tumor location and size and to evaluate brain-tissue swelling. Other routine studies are performed to check for abnormalities and establish a baseline for postoperative comparison. These studies include a chest X-ray, an electrocardiogram (EKG), bleeding time, and blood tests to check kidney function, clotting times, white blood cell count, and electrolyte, hemoglobin, and oxygen levels. A blood sample is also drawn to check the patient’s blood type in case a transfusion is needed during surgery.

The patient must not eat or drink for at least eight hours before surgery. An intravenous (IV) catheter is inserted for fluids and medications. Depending on the tumor’s location, the patient may also receive a bolus dose of an antiseizure medication, such as phenytoin, to prevent seizure activity during and after surgery. An indwelling urinary catheter is also inserted so that urine output can be monitored closely during and after the procedure. Sequential compression devices are applied to the patient’s legs and worn during and after surgery to prevent blood clot formation.

Steps of the procedure: Immediately before the procedure, an arterial catheter is inserted into the patient’s wrist to monitor blood pressure continuously during surgery. This catheter also permits blood sampling so oxygen and electrolyte levels can be monitored. A central venous catheter may also be inserted to monitor the patient’s fluid status and administer IV fluids and medications during surgery.

After the patient is anesthetized, the neurosurgeon makes an incision into the skin, and the skin is retracted. Next, an incision is made into the muscle, and the muscle is retracted. Special tools are used first to make holes in the skull bone and then to cut through the bone to make a bone flap. The bone flap is then separated from the protective layer that surrounds the brain and removed. It is kept moist during the procedure. Next, the neurosurgeon exposes the brain tissue and removes the tumor, if possible. Depending on the tumor location, a ventricular drain may be inserted to prevent hydrocephalus and monitor intracranial pressure. If a ventricular drain is not needed, then an intracranial pressure monitor sensor may be inserted. After the tumor is excised, the neurosurgeon ties off bleeding vessels and then replaces the bone flap and secures it using plates and screws. Next, the neurosurgeon closes the incision and covers it with a sterile dressing. This procedure typically takes several hours.

After the procedure: The patient is transferred to the intensive care unit (ICU) and attached to a monitor that displays heart rhythm, blood pressure, oxygen saturation, central venous pressure, intracranial pressure, and cerebral perfusion pressure. These devices help the ICU nurses monitor the patient’s condition closely. The patient may have an endotracheal tube (breathing tube) connected to a mechanical ventilator to assist with breathing, or the patient may breathe independently with supplemental oxygen. A patient who is able to breathe without help from a ventilator will be encouraged to breathe deeply and use an incentive spirometer frequently to prevent pneumonia. The head of the patient’s bed is maintained at a prescribed elevation based on the tumor’s location. Every two hours, nurses may gently roll the patient to prevent the development of pressure ulcers and pneumonia. If the patient’s neurologic status becomes unstable, however, then the patient may be unable to tolerate turning.

Nurses closely monitor the patient’s vital signs and respiratory and neurologic status to detect signs of increased intracranial pressure. If such signs are detected, then nurses administer diuretics, such as furosemide and mannitol, to decrease brain swelling. The patient will also receive a corticosteroid, such as dexamethasone, to combat inflammation. Medications such as fentanyl will also be administered to control pain. If a ventricular drain was inserted during the procedure, then the nurses will maintain the drain as ordered and closely monitor the type and amount of drainage. Nurses also monitor urine output frequently. A sudden increase in urine output without diuretic use may signal diabetes insipidus, a complication of craniotomy.

During the immediate postoperative period, it is important to keep the patient’s environment calm and quiet to minimize anxiety and to avoid increasing intracranial pressure. A drug-induced coma is sometimes necessary to control intracranial pressure that is unresponsive to other therapy; the need is rare, however, following brain tumor resection.

When the patient’s condition is stabilized and ventricular drainage is minimal, the ventricular drain is removed, and the patient’s activity level is increased. The length of hospital stay varies by the tumor location, extent of surgery, and the patient’s rate of recovery. Depending on the tumor’s extent and location, physical therapy, chemotherapy, or radiation therapy may be needed after surgical recovery.

In the 2020s, craniotomy remained a fundamental course of treatment for brain cancers. They continued to be the primary method of tumor removal. Also, they allowed doctors to accurately diagnose the type and stage of a brain tumor, allowing for more efficient and effective treatment plans. Advances in surgical techniques have minimized the invasiveness of the procedure and allowed doctors to perform target tumor removals with less healthy brain tissue being affected. These advances have also allowed patients to remain awake during the procedure, allowing doctors to check brain function with the patient continuously. Laser interstitial thermal therapy (LiTT), in which tumors are destroyed with heat through a small incision in the skull, presents a minimally invasive alternative to previous craniotomy techniques. Combining craniotomies with targeted drug therapies and CAR-T Cell therapy, an infusion previously successful in treating blood cancers, has made craniotomies more effective. 

Risks: There are many risks associated with craniotomy, including increased intracranial pressure, surgical site infection, hydrocephalus, meningitis, intracerebral hemorrhage, air embolism, seizures, stroke, cranial nerve damage, syndrome of inappropriate antidiuretic hormone (SIADH), and diabetes insipidus.

Results: Pathologic examination of the brain tumor specimen reveals the type and stage of cancer. Craniomoties allow a patient’s medical team to make informed decisions about efficient and effective treatments. 

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