Unilaterally Symptomatic Moyamoya Disease in Children: Long-term Follow-up of 20 Patients

OBJECTIVE: In unilaterally symptomatic moyamoya disease in children, it remains controversial whether bypass surgery should be performed on the asymptomatic side along with on the symptomatic side. We aimed to verify the validity of our strategy of only performing bypass surgery on the symptomatic side. METHODS: Among 91 pediatric patients with moyamoya disease who underwent bypass surgery in our department between 1980 and 2004, 20 with unilateral ischemic symptoms who were followed for more than 60 months were analyzed in the present study. Initially, we only performed bypass surgery on the symptomatic side for all 20 patients. Among these 20 patients, five developed frequent transient ischemic attacks in the initially asymptomatic side and underwent a second bypass surgery on that side (Group A), eight developed sporadic transient ischemic attacks and were followed up without surgery (Group B), and seven did not experience any ischemic symptoms on the asymptomatic side (Group C). RESULTS: In total, 18 patients progressed well without cerebral infarctions after their last surgery, although some showed deterioration of angiographic stenosis and a transient decrease in the regional cerebral blood flow or cerebral perfusion reserve. One patient in Group A had an intraventricular hemorrhage 5 years after the second operation, and one in Group B had a minor stroke on the initially asymptomatic side. CONCLUSION: In unilaterally symptomatic moyamoya disease, bypass surgery for the asymptomatic side can be delayed until the development of ischemic symptoms, such as frequent transient ischemic attacks.