Various drugs have been investigated in the treatment of moyamoya disease, all of which have proven ineffective to this point. Rather than medical therapy, Moyamoya surgery has become the treatment of choice for patients with moyamoya disease.
In adults, surgical revascularization that directly bypasses blocked arteries is the most common treatment, if feasible. Indirect revascularization procedures are more frequently used in children.
STA-MCA bypass surgery
Neurosurgeon Gregory Zipfel, MD, co-director of the Moyamoya Center at Washington University School of Medicine, performs the superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery in adult patients with moyamoya disease. After opening of the scalp, the STA is cut along its length. Care is taken to gently move the STA out of the operative field, and a portion of the skull is removed to expose the brain. The dura – the outermost membrane enveloping the brain – is opened in a way that preserves the main branches of the middle meningeal artery (MMA), which delivers blood to the meninges, or connective tissues that cover the brain. Once the MCA is identified, the arachnoid – the middle layer of membrane surrounding the brain – is opened and the MCA is positioned so that the bypass can be completed. The MCA is opened, and the STA is connected to it.
In contrast to indirect revascularization procedures, the direct STA-MCA bypass surgery provides an immediate increase to blood flow in the brain. Dr. Zipfel has performed hundreds of these direct bypass Moyamoya operations with relief of symptoms and excellent results for patients.
Indirect revascularization procedures Indirect revascularization procedures involve laying an artery or muscle on the surface of the brain. This can lead to blood vessel formation and increased blood flow to the brain over a longer period of time. Indirect procedures are performed in adults only when direct surgical bypass is not feasible and are more frequently used in children. Two of the most common indirect procedures are described.
In encephaloduroarteriosynangiosis (EDAS), one of the main scalp arteries, usually the STA, is laid directly on the surface of the brain. Over time (6-8 weeks), this may cause the growth of new arteries in the brain and provide more blood flow. Once an EDAS is performed, the STA cannot be used for a direct bypass procedure.
The encephalomyosynangiosis (EMS) involves taking the temporalis muscle, which is in the temple region of the forehead, opening the skull, and placing the muscle on the brain. Once again, over 6-8 weeks, this may result in the development of arteries and increased blood flow.
References: Suzuki J. Moyamoya Disease. Tokyo, Japan: Springer-Verlag; 1986.
Related Publication: Zipfel GJ, Fox DJ Jr, Rivet DJ. Moyamoya disease in adults: the role of cerebral revascularization. Skull Base. 2005 Feb;15(1):27-41.
WHAT TO EXPECT AFTER MOYAMOYA SURGERY
After Moyamoya surgery, patients are taken to the intensive care unit, where they usually spend about a day, and then are transferred to the hospital floor for about three days. Patients typically then go home and return to work or routine activity within 4-6 weeks.
Although Moyamoya operations are generally well tolerated, there may be some pain and tenderness in the scalp, where the incision was made, for about a week after surgery. Patients may also have headaches. Pain medication is provided to minimize the discomfort.
Your doctor and other specialists at the Moyamoya Center at Washington University will continue to follow you on an ongoing basis. Although your symptoms stop, the team wants to make sure your blood flow is improved and you are doing well after your Moyamoya operation.
For a referral to a Washington University neurologist or neurosurgeon at Barnes-Jewish Hospital, call [Dynamic_Phone_Number].