Microvascular Occlusion

Pronounced: my-CROW-vas-q-lar oh-CLUE-shun


Microvascular occlusion, also known as endovascular coil embolization, uses a metal coil to fill the aneurysm. This prevents bleeding and rupture. It may also be used if the aneurysm has already ruptured.

Reasons for Procedure    TOP

Endovascular coil embolization prevents a brain aneurysm from causing more damage. It will not fix damaged areas of the brain, but it can improve quality of life by stopping bleeding.

Brain Aneurysm

GN00002_brain aneurysm.jpg
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.

Possible Complications    TOP

Problems may occur from the procedure. Your doctor will review potential problems, like:

  • Head ache
  • Weakness
  • Numbness or tingling
  • Speech disturbances
  • Visual changes
  • Confusion, memory loss
  • Infection
  • Adverse reaction to anesthesia
  • Kidney damage
  • Blood clots
  • 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    TOP

Prior to Procedure (Non-emergency Surgery)

Your appointment before the surgery may include:

  • Physical exam and blood tests
  • Imaging tests—ultrasound, CT scan, MRI scan, or angiogram
  • Discussion of allergies
  • Discussion of medications 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

Before your procedure:

  • Arrange for a ride home.
  • Avoid food or drink after midnight the night before the procedure.
  • Discuss your medications with your doctor. You may be asked to stop taking certain medications before your procedure.

Women should let their doctor know if they are pregnant or planning to become pregnant.


Local anesthesia is usually be used. It will block any pain. You may be given medications to relax you

Description of the Procedure    TOP

You will be connected to monitors to watch your blood pressure, heart rate, and pulse during the procedure.

An IV will be placed in your arm for sedation and anesthesia.

An incision is made in the groin/inner thigh and a thin, hollow tube or sheath is inserted into the artery wall. A catheter is put in and guided by a wire through the artery and up towards the brain. Computer-aided X-rays will direct the catheter to the aneurysm and a dye is put in to define the aneurysm. A smaller catheter with a platinum coils are advanced to the aneurysm. The coils are used to fill and block the aneurysm.

The catheter is removed and the incision is closed.

Immediately After Procedure    TOP

When the procedure is done, 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 will be given medication for pain or other symptoms.

How Long Will It Take?    TOP

1-2 hours or more

How Much Will It Hurt?    TOP

Anesthesia will prevent pain during surgery. Pain and discomfort after the procedure can be managed with medications.

Average Hospital Stay    TOP

This complex procedure is done in a hospital setting. The usual length of stay is 1-2 days. Your doctor may choose to keep you longer if complications arise.

Post-procedure Care    TOP

At the Hospital

  • You will rest for several hours in the ICU.
  • Nurses will monitor your vital signs.

During your stay, the hospital staff will take steps to reduce your chance of infection, such as:

  • Washing their hands
  • Wearing gloves or masks
  • Keeping your incisions covered.

There are also steps you can take to reduce your chance of infection, such as:

  • Washing your hands often and reminding your healthcare providers to do the same
  • Reminding your healthcare providers to wear gloves or masks
  • Not allowing others to touch your incision

At Home

When you get home, you may have to adjust your activity level while you recover. This may take 3-6 weeks. Home care may include:

  • Resting when you need to
  • Caring for the wound
  • Physical or rehabilitative therapy

Call Your Doctor    TOP

Contact your doctor if your recovery is not progressing as expected or you develop complications such as:

  • Any changes in physical ability, such as balance, strength, or movement
  • Any changes to mental status, such as consciousness, memory, or thinking
  • Weakness, numbness, tingling
  • Signs of infection including fever and chills
  • Redness, swelling, increasing pain, bleeding, or discharge from the incision site
  • Headache
  • Changes in vision
  • Fainting
  • Pain that cannot be controlled with the medications you've been given
  • Persistent nausea or vomiting
  • Trouble controlling your bladder and/or bowels
  • Pain, swelling, or cramping in your legs

Call for emergency medical services 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
National Institute of Neurological Disorders and Stroke


Brain Injury Association of Canada
Heart and Stroke Foundation Canada


Cerebral aneurysm. American Association of Neurological Surgeons website. Available at:
...(Click grey area to select URL)
Updated March 2015. Accessed May 10, 2016.
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.
Subarachnoid hemorrhage.EBSCO DynaMed website. Available at:
...(Click grey area to select URL)
Updated December 31, 2015. Accessed May 10, 2016.
Treatment of brain aneurysms. The Aneurysm and AVM Foundation website. Available at:
...(Click grey area to select URL)
Accessed May 10, 2016.
Williams LN, Brown RD Jr. Management of unruptured aneurysms. Neurol Clin Pract. 2013;3(2):99-108.
Last reviewed June 2016 by Michael Woods, MD
Last Updated: 5/29/2014

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