EDAS Procedure

What is EDAS?

Encephaloduroarteriosynangiosis (pronounced en-sef-uh-loh-dur-oh-ahr-teer-ee-oh-si-nan-jee-OH-sis), or EDAS, is a surgical procedure that can help restore blood flow to the brain. EDAS can be used to treat moyamoya disease, a rare disorder in which vessels carrying oxygen-rich blood to the brain narrow over time, potentially becoming blocked. Because blood can’t flow well through these vessels, the body compensates by creating a network of tiny, abnormal blood vessels at the base of the brain. However, the new blood vessels are fragile, leaving them susceptible to bulging or breaking open.

Moyamoya can have serious neurological consequences, such as strokes and “ministrokes” called transient ischemic attacks (TIAs). Patients may develop other symptoms as well, including headaches, seizures and involuntary movements.

The goal of the EDAS procedure is to improve blood flow to the brain by bypassing the blocked vessels, preventing strokes and related problems.

Where to get care

Find a doctor

Get a second opinion

Awards & recognition

Ranked among the nation's best in 11 specialties
One of the nation's best for neurology & neurosurgery

EDAS procedure

When the EDAS procedure is performed on a child, a pediatric neurosurgeon places a branch of the superficial temporal artery (a blood vessel that normally supplies the scalp) directly on the surface of the brain. The surgery requires making a small, temporary opening in the skull.

In the following months, the artery develops new branches (called collaterals) that will eventually deliver blood to the brain. This process is thought to take about three to four months.

This type of procedure is also called indirect revascularization.

Recovery from EDAS surgery

After EDAS surgery, children typically stay in the hospital for about three to five days. After discharge, patients return for an initial follow-up visit to check that their surgical recovery is going well. Later on, the care team will order certain imaging tests to evaluate blood flow in the brain.