Novel development in treatment for hemorrhagic moyamoya disease

Abstract

Natural outcome of hemorrhagic moyamoya disease is poor, and prevention of rebleeding is the most important clinical issue. The Japan Adult Moyamoya (JAM) Trial, a unique randomized controlled trial, demonstrated the effectiveness of direct bypass surgery against rebleeding. High rebleeding risk associated with the posterior hemorrhage group, revealed by prespecified analysis of the JAM Trial, is explained by the theory of fragile periventricular anastomoses typical of the disease. Among such collateral vessels, choroidal anastomosis is located most posteriorly and should receive attention as a strong predictor of rebleeding. On the other hand, it remains unproven whether choroidal anastomosis is a predictor of de novo bleeding in nonhemorrhagic patients, and further multicenter studies are needed to identify risk factors of de novo hemorrhage and determine the optimal treatment strategy for the nonhemorrhagic less-symptomatic patients.