2016 Volume 26 Issue 1 Pages 4-11
The Japan Adult Moyamoya (JAM) Trial was a unique randomized controlled trial demonstrating the effectiveness of direct bypass surgery for hemorrhagic moyamoya disease. Prespecified subgroup analysis of the trial results demonstrated that posterior dominant initial hemorrhage is a significant predictor of rebleeding and an effect modifier for surgery. Periventricular anastomoses, fragile collaterals formed by the lenticulostriate arteries, thalamic perforators, and choroidal arteries, might be a clue to the mechanism of high rebleeding risk related to posterior dominant hemorrhage. Angiographic analyses of the JAM Trial revealed that choroidal collaterals and the involvement of the posterior cerebral artery (PCA) were associated with posterior dominant hemorrhage. Accumulating additional knowledge to better understand the role of the choroidal artery and PCA might promote further progress in the surgical treatment for hemorrhagic moyamoya disease.
