Two decades of experience in surgical revascularization of Moyamoya disease

Abstract

Objective: Moyamoya disease (MMD) is a progressive steno-occlusive cerebral vasculopathy with a formidable natural history if not intervened. A paradigm shift with more direct bypasses were performed in the past 5 years at our center. Revascularization outcomes were studied and comparison was made between the indirect and direct revascularization groups. Methods: Retrospective review of all surgically treated MMD patients in a single neurosurgical unit from November 2000 to September 2020. Results: A consecutive series of 53 patients with a mean follow-up of 73.0 months were included. 70.9% of the 86 operated hemispheres involved direct bypasses . For the past 5 years, peri-operative (<1 week) stroke rate was 6.82% per operated hemisphere. There was no significant difference in peri-operative stroke (p=.278) or hyperperfusion syndrome (p=.099) between the evascularization groups. Delayed stroke occurred in 8% of indirect and 1.67% of direct groups (p=.144). 94% of those who presented with transient ischemic attacks and underwent bypass had complete resolution of symptoms, compared to 60% in the indirect group (p=.056). The bypass cohort had lower mean mRS at last follow-up (0.63 vs 0.96, p=.033). Improved cerebral perfusion with adequate cerebral reserve was reached in 84% and 50% of the direct and indirect groups respectively (p=.005). Patency of bypass grafts was 94.6% at mean follow-up time of 29.4 months. Conclusions: Direct bypass for treatment of MMD confers low peri-operative stroke and comparable incidence of hyperperfusion syndrome, with high rate of TIA symptom resolution, low stroke recurrence and superior angiographic outcomes. Long term graft patency rate is high.