608368 Health Library | Health and Wellness | Wellmont Health System
  • Microvascular Occlusion


    Microvascular occlusion clamps off the artery leading to an aneurysm . This prevents bleeding and rupture. Sometimes a bypass procedure is done as well, rerouting blood vessels to healthy areas of the brain. A portion of the skull is removed (called a craniotomy ) and restored during this complex, open surgery.

    Reasons for Procedure

    Microvascular occlusion often treats a brain aneurysm that has ruptured and caused damage to the artery.
    Brain Aneurysm
    An aneurysm is a weakened blood vessel in the brain that collects blood. The bulging, blood-filled pocket can put pressure on parts of the brain, pressing on nearby nerves. This can cause symptoms or cause the blood vessel to rupture (hemorrhage).
    Copyright © Nucleus Medical Media, Inc.
    It will not fix damaged areas of the brain, but it can improve quality of life by stopping bleeding or preventing rupture.

    Possible Complications

    If you are having microvascular occlusion, your doctor will review a list of possible complications, which may include:
    • Weakness
    • Numbness or tingling
    • Speech disturbances
    • Visual changes
    • Confusion, memory loss
    • Seizures
    • Infection
    • Adverse reaction to anesthesia (eg, light-headedness, low blood pressure, wheezing)
    • Kidney damage
    • Blood clots ( stroke )
    • Ruptured aneurysm during surgery
    Factors that may increase the risk of complications include:
    Discuss these risks with your doctor before the surgery.

    What to Expect

    Prior to Procedure (Non-emergency Surgery)

    Your appointment before the surgery may include:
    • Physical exam, blood and imaging tests
    • Discussion of allergies
    • Discussion of medicines you are taking, including over-the-counter and herbal supplements
    • Discussion of recent illness or other conditions
    • Discussion of risks and benefits of treatment options
    • Imaging tests (ultrasound, CT , MRI ) may be done before the procedure. Bring paperwork and scans from these tests to the hospital as directed.
    • Arrange for a ride home.
    • No food or drink after midnight the night before the procedure.
    • Discuss your medicines with your doctor. You may be asked to stop taking certain medicines before your procedure. Common medicines to stop include aspirin , nonsteroidal anti-inflammatory drugs (NSAIDs), or blood thinners.
    You may meet the neurosurgeon performing the procedure.
    Women should let their doctor know if they are pregnant or planning to become pregnant.


    General anesthesia will be used. It will block any pain and keep you asleep. It is given through an IV (needle) in your hand or arm.

    Description of the Procedure

    The nurses and doctors will connect you to monitors to watch your blood pressure, heart rate, and pulse during the procedure. A catheter will be inserted to collect urine.
    An IV will be placed in your arm for sedation and anesthesia. The nurse will shave an area of your head.
    The doctor will perform a craniotomy, removing a small section of the skull to access the brain. X-rays and microscopic viewing will help the doctor find the artery leading to the aneurysm. The doctor will clamp off the artery. A bypass procedure (re-routing blood vessels toward healthy areas of the brain) may also be done.
    The section of skull is replaced and the scalp is stitched back into place.

    Immediately After Procedure

    When the procedure is done, the catheter and IV will be removed. You will need to lie still for 6-8 hours or more. You will stay in the ICU, often for a day. Your blood pressure and other vitals will be monitored closely. You may be given medicine for pain or other symptoms.

    How Long Will It Take?

    3-5 hours or more

    How Much Will It Hurt?

    You may feel a pinch when your IV is inserted. Anesthesia prevents pain during surgery. Pain or soreness after the procedure can be managed with pain medicine.

    Average Hospital Stay

    This complex procedure is done in a hospital setting. The usual length of stay is 4-6 days. Your doctor may choose to keep you longer if complications arise.

    Post-procedure Care

    At the Hospital
    • You will rest for several hours in the ICU.
    • Nurses will monitor your vital signs.
    At Home
    It will take at least 3-6 weeks to recover. When you return home, the following can help ensure a smooth recovery:
    • Rest often.
    • Keep your blood pressure under control.
    • Clean the incision site as directed. Use a soft wash cloth to gently wipe the incision area and keep it dry.
    • Ask your doctor about when it is safe to shower, bathe, or soak in water.
    • Take medicine as directed.
    • Do rehabilitative therapy as directed.
    • Be sure to follow your doctor’s instructions .

    Call Your Doctor

    After you leave the hospital, contact your doctor if any of the following occurs:
    • Changes in physical ability—balance, strength, or movement
    • Changes to mental status—level of consciousness, memory, thinking, or responsiveness
    • Weakness, numbness, tingling
    • Signs of infection, including fever and chills
    • Redness, swelling, increasing pain, a lot of bleeding, or any discharge from the incision site
    • Headache that does not go away
    • Changes in vision
    • Fainting
    • Pain that you cannot control with the medicines you have been given
    • Nausea and/or vomiting that you cannot control with the medicines you were given, or that continue for more than two days after leaving the hospital
    • Trouble controlling your bladder and/or bowels
    Call for medical help or go to the emergency room right away if any of the following occurs: 
    • Seizure
    • Shortness of breath or chest pain
    • Loss of consciousness
    If you think you have an emergency, call for medical help right away.


    The Brain Aneurysm Foundation http://www.bafound.org/

    Center for Vascular Surgery (INN) http://neuro.wehealny.org/endo/proc%5Fembolizations.asp

    National Institute of Neurological Disorders and Stroke http://www.ninds.nih.gov/


    Brain Injury Association of Alberta (BIAA) http://www.biaa.ca/

    Heart and Stroke Foundation Canada http://ww2.heartandstroke.ca/splash/

    Hotchkiss Brain Institute http://www.hbi.ucalgary.ca/


    American Association of Neurological Surgeons. Treatment options for cerebral aneurysms. American Association of Neurological Surgeons website. Available at: http://www.neurosurgerytoday.org/what/patient%5Fe/treatment.asp . Accessed June 3, 2010.

    The Aneurysm and AVM Foundation. Brain aneurysms. The Aneurysm and AVM Foundtion website. Available at: http://www.taafonline.org/ba%5Ftreatment.html#ba%5Fclipping . Accessed June 3, 2010.

    Cowen J, Ziewacz J, Dimick J, et al. Use of endovascular coil embolization and surgical clip occlusion for cerebral artery aneurysms. J Neurosurg . 2007;107:530-535. Available at: http://thejns.org/doi/pdf/10.3171/JNS-07/09/0530 . Accessed June 4, 2010.

    Mayo Clinic. Brain aneurysm. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/brain-aneurysm/ds00582 . Accessed June 3, 2010.

    National Institute of Neurological Disorders and Stroke. Cerebral aneurysm fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/cerebral%5Faneurysm/detail%5Fcerebral%5Faneurysm.htm . Accessed June 3, 2010.

    Neff D. Brain Aneurysm. EBSCO Patient Education Reference Center. Available at:  http://www.ebscohost.com/thisTopic.php?marketID=16&topicID=1034 . Published May 1, 2010. Accessed June 2, 2010.

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