Surgery is the preferred way to treat moyamoya. The goal of surgery is to go around the blockage and allow new blood vessels to develop to bring blood and oxygen to the brain.
The moyamoya blood vessels and the areas of the brain they affect are sensitive. They can be affected by changes in blood pressure, the amount of blood flow and the amount of carbon dioxide in the blood. Under anesthesia it can be hard to control all these factors, especially in children.
The Cedars-Sinai Neurovascular Center relies on the expertise of pediatric neurosurgical specialists to deal with the special needs of children undergoing neurovascular surgery. Children undergoing treatment for moyamoya need a different type of anesthesia for this surgery than is given for almost any other type of neurosurgical procedure.
With trained, experienced neurovascular surgeons, the risks of this surgery are generally low. The long-term outlook for children who have been treated for moyamoya is good.
Surgical Approaches for Moyamoya
Surgery for moyamoya uses the idea that a brain starved for blood and oxygen will reach out to grasp and develop new and more efficient means of bringing blood to the brain. The brain does this by bypassing the areas of blockage.
- Encephaloduroarteriosynangiosis (EDAS) procedure. This procedure requires freeing up, without severing, a scalp artery over a course of several inches and then making a small temporary opening in the skull directly beneath the artery. The artery is then sutured to the surface of the brain and the bone replaced.
- Encephalomyosynangiosis (EMS) operation. Here a muscle that on the temple and slightly on the forehead region of the skull, is freed from some attachments. A hole it then made in the skull under this muscle and it is then placed onto the surface of the brain.
- Superficial temporal artery-middle cerebral artery (STA-MCA), in which a scalp artery is directly sutured to a brain surface artery.
- Multiple small holes (burr holes) are placed in the skull to allow for growth of new vessels into the brain from the scalp.
Recovery from Surgery for Moyamoya
While symptoms may seem to improve almost immediately after surgery, it will usually takes six to 12 months before new vessels can develop sufficiently.
If a patient has had major bleeding into the tissues of the brain from moyamoya, the damage is usually permanent. Prompt treatment is important to prevent a permanent loss of function as much as possible.