Brain aneurysm repair

There are two common methods used to repair an aneurysm:

• Clipping is done during an open craniotomy.
• Endovascular repair (surgery), most often using a coil or coiling and stenting (mesh tubes), is a less invasive and more common way to treat aneurysms.

During aneurysm clipping:

• You are given general anesthesia and a breathing tube.
• Your scalp, skull, and the coverings of the brain are opened.
• Your brain is gently retracted to reach the aneurysm.
• One or more metal clips are placed at the base (neck) of the aneurysm to prevent it from breaking open (bursting).

During endovascular repair (surgery) of an aneurysm:

• You may have general anesthesia and a breathing tube. Or, you may be given medicine to relax you, but not enough to put you to sleep.
• A catheter is guided through a small cut in your groin into and through the femoral artery and then guided through your arteries until it reaches the artery in your brain where the aneurysm is located.
• Contrast material is injected through the catheter. This allows the surgeon to view the arteries and the aneurysm on a monitor in the operating room.
• Thin metal wires are put into the aneurysm. They then coil into a mesh ball. For this reason, the procedure is also called coiling. Blood clots that form around this coil prevent the aneurysm from breaking open and bleeding. Sometimes stents (mesh tubes) are also put in to hold the coils in place and make sure the blood vessel stays open.
• During and right after the procedure, you may be given a blood thinner, such as heparin, clopidogrel, or aspirin. These medicines prevent dangerous blood clots from forming in the stent.

If an aneurysm in the brain breaks open (ruptures), it is an emergency that needs medical treatment in a hospital. Often a rupture is treated with surgery, especially endovascular surgery.

A person may have an unruptured aneurysm without any symptoms. This kind of aneurysm may be found when an MRI or CT scan of the brain is done for another reason.

Aneurysms that have never bled, especially if they are very small (less than 3 millimeters [mm] or 0.12 inch [in] at their largest point), do not need to be treated right away. These very small aneurysms are less likely to rupture.

Your surgeon will help you decide whether it is safer to have surgery to block off the aneurysm before it can break open or to monitor the aneurysm with repeated imaging until surgery becomes necessary. Some small aneurysms will never need surgery.

Risks of anesthesia and surgery in general are:

• Reactions to medicines
• Breathing problems
• Bleeding, blood clots, or infections

Risks of brain surgery are:

• Blood clot or bleeding in or around the brain
• Brain swelling
• Infection in the brain or parts around the brain, such as the skull or scalp
• Seizures
• Stroke

Surgery on any one area of the brain may cause problems that may be mild or severe. They may last a short while or they may not go away.

Signs of brain and nervous system (neurological) problems include:

• Behavior changes
• Confusion, memory problems
• Loss of balance or coordination
• Numbness
• Problems noticing things around you
• Speech problems
• Vision problems (from blindness to problems with side vision)
• Stroke-like symptoms such as muscle weakness or paralysis on one side of the body
  

You may need another surgery to further treat the aneurysm or to treat a complication.

This procedure is often done as an emergency.

If it is not an emergency, tell your surgeon or nurse if:

• You are or could be pregnant
• You are taking any medicines, including medicines, drugs, supplements, or herbs you bought without a prescription

Planning for your surgery:

• If you have diabetes, heart disease, or other medical conditions, your surgeon may ask you to see the provider who treats you for these conditions. 
• If you smoke, it's important to cut back or quit. Smoking can slow healing and increase the risk for blood clots. Ask your provider for help quitting smoking.
• If needed, prepare your home to make it easier to recover after surgery.
• Ask your surgeon if you need to arrange to have someone drive you home after your surgery.

During the week before your surgery:

• You may be asked to temporarily stop taking medicines that keep your blood from clotting. These medicines are called blood thinners. This includes over-the-counter medicines and supplements such as aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn), and vitamin E. Some other prescription medicines are also blood thinners.
• Ask your surgeon which medicines you should still take on the day of surgery.
• Let your surgeon know about any illness you may have before your surgery. This includes COVID-19, a cold, flu, fever, herpes outbreak, or other illness. If you do get sick, your surgery may need to be postponed.

On the day of surgery:

• Follow instructions about when to stop eating and drinking.
• Take the medicines your surgeon told you to take with a small sip of water.
• Arrive at the hospital on time.

A hospital stay for endovascular repair of an aneurysm may be as short as 1 to 2 days if there was no bleeding before surgery.

The hospital stay after craniotomy and aneurysm clipping is usually 4 to 6 days. If there is bleeding or other problems, such as narrowed blood vessels (vasospasm) in the brain or a buildup of fluid in the brain, the hospital stay can be 2 weeks, or longer.

You will probably have imaging tests of the blood vessels (angiogram) in the brain before you are sent home, and possibly once a year for a few years.

Follow instructions on caring for yourself at home.

Ask your surgeon if it will be safe for you to have imaging tests such as an angiogram, CT angiogram, or MRI scans of the head in the future.

After successful surgery for a bleeding aneurysm, it is uncommon for it to bleed again.

The outlook also depends on whether brain damage occurred from bleeding before, during, or after surgery.

Most of the time, surgery can prevent a brain aneurysm that has not caused symptoms from becoming larger and breaking open.

You may have more than one aneurysm or the aneurysm that was coiled might grow back. After coiling repair, you will need to be seen by your surgeon every year.

Aneurysm repair - cerebral; Cerebral aneurysm repair; Coiling; Saccular aneurysm repair; Berry aneurysm repair; Fusiform aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm

American Stroke Association website. What you should know about cerebral aneurysms. www.stroke.org/en/about-stroke/types-of-stroke/hemorrhagic-strokes-bleeds/what-you-should-know-about-cerebral-aneurysms#. Reviewed December 5, 2018. Accessed April 24, 2026.

Le Roux PD, Mack WJ, Winn HR. Surgical decision making for the treatment of intracranial aneurysms. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 427.

Levy ML, Levy DM, Manna B. Pediatric cerebral aneurysm. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. www.ncbi.nlm.nih.gov/books/NBK537085/. Updated August 8, 2023. Accessed April 24, 2026.

Macdonald RL. Perioperative management of subarachnoid hemorrhage. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 428.

National Institute of Neurological Disorders and Stroke website. Cerebral aneurysms. www.ninds.nih.gov/health-information/disorders/cerebral-aneurysms. Updated March 13, 2026. Accessed April 24, 2026.

Szeder V, Tateshima S, Jahan R, Saver JL, Duckwiler GR. Intracranial aneurysms and subarachnoid hemorrhage. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 67.

Updated by: Luc Jasmin, MD, Ph.D., FRCS (C), FACS, Department of Neuroscience, Guam Regional Medical City, Guam; Department of Surgery, Johnson City Medical Center, TN; Department of Maxillofacial Surgery at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.