Medically reviewed by Eugenia Ayrian, MD, FASA, June 28, 2024.

Brain Surgery

Brain surgery is used to treat a variety of conditions, such as tumors, blood clots, aneurysms, epilepsy, and Parkinson’s disease. It is performed by a neurosurgeon and involves an anesthesiologist with extensive knowledge of the types of anesthesia, monitoring, and postoperative care required for these sensitive operations. In some cases, this anesthesiologist will be a neuroanesthesiologist who has received advanced clinical training in anesthesia for brain and spinal surgeries.

What are some types of brain surgery?

These are some of the most common operations involving the brain or areas around it. Some of the explanations below are derived from information obtained from the National Cancer Institute.

• Biopsy. A biopsy is a procedure to remove a small sample of abnormal tissue from the body to have it examined under a microscope by a pathologist. To perform this operation on or near the brain, the surgeon may cut the scalp and remove a piece of the skull bone to access the brain and remove a sample of brain tissue or a tumor. In a less invasive biopsy, the surgeon drills a small hole in the skull and inserts a thin, hollow needle to remove brain cells or a tumor sample.
• Craniotomy. A piece of the skull is removed to give doctors access to the brain to remove a brain tumor, abnormal tissue, blood, or blood clots; relieve pressure after an injury or stroke; repair a brain aneurysm or skull fracture; or treat other brain conditions. The piece of the skull is put back in place after surgery.
• Deep brain stimulation (DBS). A battery-operated medical device called an implantable pulse generator is implanted to deliver electrical stimulation to specific areas in the brain. DBS is most commonly used for Parkinson’s disease and other movement disorders, as well as for seizure disorders.
• Neuroendoscopy. This minimally invasive technique involves threading a thin tube called an endoscope through the mouth, nose, or small incisions in the skull to access or remove brain tissue. The endoscope has a light and camera on the end, and the surgery is performed with tools placed through the endoscope. Endoscopic transsphenoidal surgery (also called endoscopic pituitary surgery) is one type of neuroendoscopy. It involves threading the endoscope through the nose to remove brain tumors and lesions near the pituitary gland, just behind the bridge of the nose.
• Posterior fossa decompression. This surgery is performed to reduce pressure on the cerebellum and spinal cord. It is used to treat Chiari malformation and other conditions that compress the cerebellum and brain stem. The surgeon makes an incision at the back of the patient’s head to remove a small portion of the bone at the bottom of the skull. This removal creates more space for the cerebellum and brain stem and relieves pressure on the spinal cord.
• Thrombectomy. This procedure is most commonly used on patients with a blood clot in a brain artery, a cerebral aneurysm (a weakened and bulging area in an artery wall), or a ruptured aneurysm that causes bleeding into the brain. The surgeon guides surgical instruments such as a catheter or thin metal wires through a large blood vessel in the patient’s groin to reach the brain vessels, using contrast dye to identify the problematic blood vessel without opening up the skull. Then the surgeon uses a device such as a stent retriever or aspiration catheter to remove the clot. In certain cases, thrombectomy can significantly reduce the risk of neurological damage by quickly restoring normal blood flow.

Some brain cancer patients are treated with stereotactic surgery. This is not a surgery in the common understanding of the term, because no incision is involved. Stereotactic surgery is an external radiation treatment that uses special equipment to deliver a high dose of radiation that precisely targets tumors or other lesions. This targeting minimizes damage to surrounding healthy tissue.

What is the role of the anesthesiologist?

Anesthesiologists play a critical role before, during, and after the operation to help enable the best outcome and recovery. An anesthesiologist is a medical doctor who specializes in anesthesia, pain management, and critical care medicine.

• For nonemergency surgery, an anesthesiologist typically will meet with you several days before or the day of your surgery to explain the anesthesia care, risks, and side effects. The anesthesiologist will review your medical history and diagnostic tests, ask about prior reactions to anesthesia, and advise you on which of your medications you should stop or continue taking in the days leading up to the operation.
• The information gathered during this appointment will help the anesthesiologist choose medications that will provide safe and effective anesthesia while creating the least possible interference with the surgical procedure.
• Before surgery, the anesthesiologist will explain how your condition will be monitored during the operation (e.g., using EEGs, EKGs, catheters) and what is likely to happen afterward, such as whether you may need to spend time in the intensive care unit. The anesthesiologist will answer all your questions and ask you to sign the consent form for anesthesia.
• During the operation, the anesthesiologist will monitor all vital functions, as well as nerve and muscle responses. Your anesthesiologist will also work to maintain healthy brain blood flow, blood pressure, and oxygenation levels, in addition to providing pain control.
• After the procedure, the anesthesiologist may provide medications to address potential side effects of brain surgery, such as seizures or nausea. Anesthesiologists are also experts in pain management and can determine the best options for pain relief, as needed.

What type of anesthesia will be used for my surgery?

General anesthesia is frequently used and is especially important for high-precision tumor removal because you must remain absolutely still. Under general anesthesia, you will be unconscious throughout the operation.

Some surgeries are done under monitored anesthesia care or sedation. You receive medicines to relax you and block pain, but you remain either conscious or in an unconscious state from which the team can easily wake you when necessary during surgery. This allows for direct feedback from you, which can be extremely important. This is often referred to as “awake” surgery and is discussed in more detail below.

What is “awake” brain surgery?

Awake brain surgery is used for operations to treat epileptic seizures and Parkinson’s disease and for the removal of brain tumors near portions of the brain that can affect critical functions. Remaining conscious allows you to answer questions that can help the surgeon identify areas of the brain affecting functions like vision, movement, or speech. The surgeon uses that information to precisely target the treatment.

In awake brain surgery, you still receive sedation and pain relief medication from your anesthesiologist, who will monitor your blood pressure, heart rate, and oxygenation and always remain at your side. Additionally, your anesthesiologist may inject a local anesthetic into certain parts of your face and head to block pain during surgery, and your surgeon may administer more anesthetic in the area of the wound to numb your scalp.

You will not necessarily be fully aware or conscious during the entire procedure. The anesthesiologist can adjust levels of medication during surgery to wake you only at necessary times. Even then, you may not need to be brought to a state of full consciousness in which you can speak. Instead, you may be brought to a state in which you can respond by squeezing a hand or giving some other signal. Some patients do not even remember they were awake.

Preoperative discussions with your anesthesiologist can help reduce any anxiety you might feel about this type of surgery.

How do I manage pain during my recovery?

Anesthesiologists are also pain management specialists for conditions related to surgery. Before the operation, the anesthesiologist may ask about your pain tolerance to help gauge how best to manage any postoperative pain, guiding decisions such as the proper narcotics dosage and the feasibility of nonnarcotic pain relief medication. The anesthesiologist will consult with you after surgery and may adjust your treatment based on the level of pain you are experiencing.

The anesthesiologist will also consider factors such as a pain medication’s potential impact on oxygenation and breathing during your initial recovery or on your ability to interact promptly during the postoperative assessment of your neurological status. This weighing of benefits and risks is especially important for pain relief medication taken during the first 24 hours after any major neurosurgical procedure.

Anesthesiologists are the most highly skilled medical experts in anesthesia care, pain management, and critical care medicine. They have the education and training that, in some circumstances, can mean the difference between life and death.