Ha EJ, Kim KH, Wang KC, et al. - In this longitudinal and cross-sectional analysis, the researchers assessed the long-term outcomes of indirect bypass surgery in a cohort of children with moyamoya disease in a single center. In total, 772 children received indirect bypass surgery; of these, 629 who were followed up for > 5 years were included. The investigators performed the cross-sectional analysis based on either Karnofsky Performance Scale or Lansky Play Performance Scale to determine overall clinical outcomes and factors linked to unfavorable outcomes. To analyze the longitudinal impact of surgery, the yearly risk of symptomatic infarction or hemorrhage on the operated hemisphere after indirect bypass surgery was calculated with a person-year method, and the event-free survival rate was assessed using the Kaplan-Meier method. In 95% of patients, the overall clinical outcome was favorable, and the annual risks of symptomatic infarction and hemorrhage on the operated hemispheres were 0.08% and 0.04%, respectively. Moreover, the 10-year event-free survival rates for symptomatic infarction and hemorrhage were 99.2% and 99.8%, respectively. Overall, indirect bypass surgery could offer adequate long-term improvement in overall clinical outcome and prevention of recurrent stroke in pediatric patients with moyamoya disease.