Meta-analysis of the surgical outcomes of symptomatic moyamoya disease in adults

OBJECTIVE The purpose of this study was to evaluate treatment outcomes of future stroke prevention, perioperative complications, and angiographic revascularization in adults with symptomatic moyamoya disease (MMD) according to treatment modalities and surgical techniques. METHODS A systemic literature review was performed based on searches of the PubMed, Embase, and Cochrane Central databases. A fixed-effects model was used in cases of heterogeneity less than 50%. Publication bias was determined by Begg’s funnel plot, Egger’s test of the intercept, and the Begg and Mazumdar rank correlation test. RESULTS Eleven articles were included in the meta-analysis. Bypass surgery significantly decreased the future stroke events compared with conservative treatments in adult MMD (odds ratio [OR] 0.301, p < 0.001). Direct bypass showed better future stroke prevention than indirect bypass (OR 0.494, p = 0.028). There was no meaningful difference in perioperative complications between direct and indirect bypass (OR 0.665, p = 0.176). Direct bypass was associated with better angiographic outcomes than indirect bypass (OR 6.832, p < 0.001). CONCLUSIONS Bypass surgery can be effective in preventing future stoke events in adults with MMD. Direct bypass seems to provide better risk reduction with respect to stroke than indirect bypass in these patients.