Stroke prevention by direct revascularization for patients with adult-onset moyamoya disease presenting with ischemia

OBJECTIVE Moyamoya disease (MMD) is a progressive disease that can cause recurrent stroke. The authors undertook this retrospective case-control study with a large sample size in an attempt to assess the efficacy of direct or combined revascularization surgery for ischemia in adults with MMD. METHODS The authors investigated cases involving patients with moyamoya disease presenting with ischemia who visited Seoul National University Bundang Hospital and Seoul National University Hospital between 2000 and 2014. Among 441 eligible patients, 301 underwent revascularization surgery and 140 were treated conservatively. Variables evaluated included age at diagnosis, sex, surgical record, Suzuki stage, and occurrence of stroke. Patients were stratified into 2 groups based on whether or not they had undergone revascularization surgery. Actuarial 1-, 5-, and 10-year stroke rates were calculated using the life table method. Risk factor analysis for 5-year stroke occurrence was conducted with multivariate regression. RESULTS Of the 441 patients, 301 had been surgically treated (revascularization group) and 140 had not (control group). The mean follow-up durations were 45 and 77 months, respectively. The actuarial 10-year cumulative incidence rate for any kind of stroke was significantly lower in the revascularization group (9.4%) than in the control group (19.6%) (p = 0.041); the relative risk reduction (RRR) was also superior (52.0%) in the revascularization group, and the number needed to treat was 10. The 10-year rate of ischemic stroke was greater (13.3%) in the control group than in the revascularization group (3.9%) (p = 0.019). The RRR for ischemic stroke in the revascularization group was 70.7%, and the number needed to treat was 11. However, the actuarial 1- and 5-year rates of ischemic stroke did not significantly differently between the groups. Overall, revascularization surgery was shown to be an independent protective factor, as revealed by multivariate analysis. CONCLUSIONS Direct or combined revascularization for patients with adult-onset moyamoya disease presenting with ischemia can prevent further stroke.