Moyamoya surgical treatments

Several different surgeries can be used to treat Moyamoya disease. These surgeries create detours around the damaged blood vessels and restore blood flow to the brain. By improving the blood flow, we can help prevent ministrokes, strokes and bleeding.

The surgeries involve either direct or indirect bypass grafts. The direct bypass method, called an extracranial-tointracranial bypass, improves blood flow immediately. It is the preferred method, and it is the one that our surgeons use most frequently for Moyamoya disease.

When direct bypass is not an option, surgeons may perform one of three types of indirect bypass grafts. Indirect bypasses open new routes for blood flow, but they take three to six months to mature and to yield full results. Still, for patients who face higher risks with direct bypass and for those who may not have a suitable graft available, the indirect methods are good options.

Our surgeons have advanced skills in microsurgery. They have a high rate of success in all performing all types of cerebral bypass surgeries.

Direct Bypass Procedure


A direct bypass is illustrated. The scalp vessel known as the superficial temporal artery (STA) is redirected and sutured using fine sutures to a blood vessel on the surface of the brain. This immediately improves blood flow to the part of the brain that is chronically deprived of oxygen in Moyamoya patients.

Indirect Bypass Procedure


In certain patients, an “onlay” procedure where the superficial temporal artery (STA) is placed on the surface of the brain may be the best option for providing additional blood flow. New vessels sprout off the STA into the surrounding brain. Blood vessels also grow from the reflected dura into the brain in order to provide more oxygen. This process of new blood vessel growth usually matures about 6 months after surgery.

Moyamoya Surgery


The surgical exposure includes both the frontal and temporal lobes. The fissure between the two lobes carries the majority of the blood vessels that provide oxygen to this region of the brain. These arteries are exposed during surgery and the scalp artery known as the superficial temporal artery (STA) is exposed as well in order to prepare for the bypass procedure.