Revascularization Surgery in Patients with Ischemic-Type Moyamoya Disease: Predictors for Postoperative Stroke and Long-Term Outcomes

Abstract

Recurrent stroke after surgical revascularization is still a big issue for moyamoya disease (MMD). This study aims to identify predictors for postoperative stroke and unfavorable outcome in ischemic-type MMD. We identified a consecutive series of patients with ischemic-type MMD who underwent revascularization between January 2005 and December 2012. Predictors for postoperative stroke and functional outcomes were assessed with logistic and Cox regression analysis. A total of 346 patients underwent 437 revascularization procedures and the mean follow-up period was 4.0 years. The incidence of perioperative stroke was 6.9%. Being adult at onset (odds ratio [OR], 5.033; 95% confidence interval [CI], 1.447-17.506; P= 0.011) and posterior cerebral artery (PCA) stenosis (OR, 3.364; 95% CI, 1.588-7.265; P= 0.002) before surgery were predictors of perioperative stroke. The annual subsequent stroke rate beyond 30 days after surgery was 1.2%. Subsequent stroke events tended to occur throughout the first 5 years after surgery in adults, whereas in children they mainly occurred within the first 2 years after surgery. Age at onset (OR, 1.025; 95% CI, 1.003-1.048; P=0.023), ischemic stroke or transient ischemic attack at presentation (OR, 2.703; 95% CI, 1.062-6.875; P= 0.037), and PCA involvement (OR, 2.664; 95% CI, 1.462-4.854; P= 0.001) were associated with higher risk of overall postoperative stroke. PCA involvement (OR, 2.62; 95% CI, 1.33-5.15; P=0.005), internal carotid artery supraclinoid segment occlusion (OR, 2.76; 95% CI, 1.27-6.03; P= 0.011), and older age at onset (OR, 1.03; 95% CI, 1.01-1.05; P= 0.033) were predictive of unfavorable outcome. Patients with ischemic-type MMD at an older age and more severe angiopathy might be at higher risk of recurrent stroke and unfavorable outcome after revascularization.