BACKGROUND AND OBJECTIVES: Despite a substantial body of literature describing the efficacy of revascularization compared with conventional management of moyamoya disease (MMD), the impact of the timing of revascularization relative to stroke onset remains inadequately characterized. The aim of this review was to synthesize existing research to guide clinicians in the optimal timing of revascularization in symptomatic MMD. METHODS: A comprehensive literature review was performed to identify studies reporting on timing of revascularization. Studies were divided into revascularization within 3 months of stroke, between 3 and 6 months of stroke, or >
6 months from stroke event. RESULTS: A total of 3049 cases and 3151 treated cerebral hemispheres were included. There were 91 individuals (2.98%) in the 3 months to intervention cohort, 152 (4.92%) individuals in the 3 to 6 months to the intervention cohort, and 2806 (92.0%) individuals in the >
6 months to the intervention cohort. The average follow-up time was 43.8 ± 35.19 months. Clinical improvement was reported in 83.4% of cases overall. The 3-to-6-month poststroke preoperative interval has the highest frequency of clinical improvement (90.2%), followed by the >
6-month preoperative interval (83.4%). The preoperative interval of <
3 months had the lowest frequency of clinical improvement (76.5%). Comparison of average treatment effect in the treated demonstrated reduced frequency of improved clinical outcome (Mean difference: -22.6, SE: 9.15, CONCLUSION: The findings of this meta-analysis suggest that, in cases where it is clinically feasible to delay revascularization following an acute neurological event in patients with MMD, postponing intervention is warranted.