Preparation for Surgery for Moyamoya Disease in Children

Indications for Procedure

• Transient ischemia: Reversible transient ischemic symptoms such as intermittent weakness, numbness, dysphasia, headache, seizure, involuntary movement are good indications for revascularization surgery.
• Hemorrhage: Recent reports from Japan Adult Moyamoya Trial support preventive effects of revascularization surgery on re-bleeding risk in adult Moyamoya Disease patients, especially those who suffered from posterior bleeding at the territory of choroidal or posterior cerebral artery (45). However, its value in children and for prevention of the first bleeding is unknown.
• Decreased vascular reserve: Decreased vascular reserve in the area of non-infarcted ischemic brain is a good indication for revascularization surgery and the postoperative outcome is excellent in such cases.
• No extensive infarction: Extensive cerebral infarction is not an indication for surgery. In this case, preservation of the contralateral cerebral hemisphere by revascularization surgery is utmost concern if it is ischemic (as is usual in Moyamoya Disease). Bilateral cerebral infarction may cause serious disturbances of cognition and emotion.
• Asymptomatic children: In cases of children diagnosed with moyamoya radiographically, but without clinical symptoms, surgery may still be indicated if there is evidence of significant hemodynamic impairment or ongoing progression of disease (39).

Pre-operative Orders

• Intravenous fluid: During the perioperative period, hypovolemia, anemia, and hypotension should be avoided. Consequently, adequate routes for infusion of fluid and blood should be instituted.
• Prophylactic anticonvulsant: When convulsion occurs during the perioperative period it may cause or aggravate infarction. Therefore, preventive anticonvulsant medication is recommended in some cases, particularly if the child had an antecedent history of seizure.

Anesthetic Considerations

• Attention to maintaining perfusion: Hyperventilation, hypoventilation, hypotension, hyperthermia, hypovolemia and anemia are avoided so perfusion of the brain is optimized.

Devices to be Implanted

• Bone flap fixation:  Desired devices for bone flap fixation are requested.

Ancillary/Specialized Equipment

• Surgical microscope
• Microdoppler: The microdoppler is used for mapping out the donor branch.
• Microdissection instruments: Surgical instruments may include an arachnoid blade, and bypass too