Brain, Nervous System and Mental Conditions

Moyamoya Treatment

The only treatment for moyamoya is surgery to bring new blood supply to the brain. Seattle Children’s has experts in revascularization, a surgery that lowers the risk of stroke.

Your child’s team at Seattle Children’s will recommend steps to help reduce stroke risk. These may include taking a low dose of aspirin to prevent small blood clots and avoiding medicines that constrict blood vessels.

Surgery for Moyamoya

There are two main surgeries to improve blood flow in children with moyamoya:

  • Indirect revascularization – Surgery that prompts new blood vessels to grow into the brain over time
  • Direct revascularization – Surgery that sends more blood into blood vessels already in the brain

For both surgery methods, the neurosurgeon uses the child’s superficial temporal artery (STA). Normally, this artery comes up from the neck and goes under the scalp on the side of the head.

  • With the indirect method, the neurosurgeon frees part of the STA from the scalp, places it inside the skull and attaches it to the surface the brain. Over time, new blood vessels grow and branch off the STA, bringing more blood down into the brain. This surgery is called pial synangiosis (pronounced PEE-ul sin-an-JOE-sis) or encephaloduroarteriosynangiosis.
  • With the direct method, the neurosurgeon connects the STA to another artery that is already inside the skull and already brings blood to the brain (middle cerebral artery). This surgery creates a detour; blood that would have gone to the scalp goes to the brain instead. This surgery is called superficial temporal artery–middle cerebral artery anastomosis, or STA-MCA anastomosis.

Whenever possible, we use the indirect method for two reasons:

  • We believe it is safer for children.
  • It doesn’t depend on good blood flow through the middle cerebral artery.

We tailor your child’s treatment to their exact needs. The neurosurgeon considers all aspects of your child’s anatomy and health, and then recommends the surgery that is best for your child.

Children who experience frequent transient ischemic attacks (TIAs) or strokes before surgery are at greater risk of having a stroke during surgery or in the 1 to 2 weeks following. Overall, this risk is low – only 4% for patients at Seattle Children’s who have pial synangiosis. To help reduce the risk, we usually wait 4 to 6 weeks after a stroke to do surgery.

Care after Surgery

Most children do very well after surgery. Your child will have pain medication to keep them comfortable. We will watch your child in the intensive care unit for 1 to 2 days until we are sure they are doing well. Then your child will move to a regular hospital room to stay for 2 to 3 days. Most children can go home 4 to 5 days after surgery.

Before your child goes home, your child’s team will explain any special care or precautions needed after surgery. Here are some typical things you can expect:

  • Most children can return to regular activities at home and school within 2 to 4 weeks after surgery.
  • Children should avoid strenuous activities for 3 months and then slowly increase their activity over the next few months.
  • To protect the brain and its arteries, children should wear a helmet during activities like biking, skateboarding or inline skating.
  • Until cleared by their doctor, children should avoid activities that involve head contact.

About 2 weeks after surgery, the neurosurgery team will see your child for a follow-up visit to check their healing and remove their stitches.

After pial synangiosis, the process of new arteries growing into the brain begins. This continues for at least a year. During this time, headaches or TIAs linked to moyamoya might occur, but should improve. We ask you to keep track of all symptoms your child has so we can talk about them at follow-up visits and provide any tests or treatments your child needs.

A neurosurgery nurse practitioner will see your child 2 weeks after surgery to make sure the incision is healing properly. A neurosurgeon and a neurologist will see most children for a follow-up visit in about 3 months. We tailor the follow-up schedule to your child’s needs. Your child will have an MRI (magnetic resonance imaging) scan and a cerebral angiogram to check how much blood flow has returned to the affected areas of the brain. Your child will then be followed by neurosurgery and neurology, with brain scans every year.

Although moyamoya surgery decreases the risk of stroke, children can still have strokes. Even after surgery, some arteries in your child’s brain will not be as large as normal. Also, some children who have moyamoya on only one side of their brain may develop it later on the other side and need surgery for that side as well.

More Ways to Reduce Stroke Risk

Your child’s doctor may recommend giving your child a low dose of aspirin each day to prevent blood clots that could block small arteries. Other steps that can help reduce your child’s risk of stroke:

  • Provide water and other fluids each day to keep their blood volume and blood pressure high enough for good blood flow.
  • Avoid medicines that constrict the blood vessels, such as medicines used to treat a migraine, unless recommended by a doctor who knows about moyamoya and your child’s health history.
  • Use caution with medicines that increase the risk of blood clots, such as birth control pills.
  • Protect the brain and its arteries with a helmet during activities like biking.
  • Avoid strenuous activity in the months right after surgery. If you have any questions about the right type or level of activity for your child, your child’s team is here to help.

The team will talk with you in detail about reducing the risk of stroke in your child.

Ongoing Care

Seattle Children’s provides long-term follow-up care to monitor your child’s health, prevent complications, manage symptoms or other health problems and give your child the best quality of life. Ongoing care will depend on your child’s needs. For example, children whose brains were damaged by reduced blood flow might benefit from a neuropsychological evaluation and rehabilitation services.

When your child becomes an adult, we make sure they continue to get the care they need by partnering with neurosurgeons at Harborview Medical Center who treat moyamoya.