Outcomes of Bypass Surgery in Patients with Moyamoya Syndrome Secondary To Sickle Cell Disease: a Multicenter Study

Background: Moyamoya syndrome (MMS) associated with sickle cell disease (SCD) is a severe vasculopathy that significantly increases stroke risk. While cerebral revascularization is increasingly considered in this population, concerns about perioperative safety and long-term outcomes have limited its use in clinical practice. Methods: We conducted a multicenter, retrospective cohort study of 553 patients with MMS who underwent surgical revascularization across 13 centers. Patients were grouped by SCD status (SCD-MMS vs. moyamoya disease (MMD)). Primary outcomes included perioperative stroke, perioperative complications, and functional status at discharge. Secondary outcomes included length of stay, and follow-up stroke. Results: Of 553 patients, 32 (5.8%) had SCD. There were no significant differences in overall perioperative stroke (OR 1.05, 95% CI 0.19 to 5.54), symptomatic perioperative stroke (OR 0.94, 95% CI 0.09 to 8.94), perioperative complications (OR 1.66, 95% CI 0.47 to 5.86), or follow-up stroke (OR 0.88, 95% CI 0.17 to 4.55). Functional outcomes at discharge were similarly favorable in both groups (mRS 0–1: OR 0.84, 95% CI 0.29 to 2.40). SCD was associated with a longer hospital stay (beta 2.78 days, 95% CI 0.60 to 4.96). Conclusion: Surgical revascularization for MMS in patients with SCD does not confer additional procedural risk and yields outcomes comparable to those of patients without SCD. These findings support the role of bypass surgery as a viable treatment option in this high-risk population.