Japanese Adult Moyamoya trial suggest EC-IC bypass may prevent re-bleeds
Optimal management of many patients with adult-onset moyamoya disease who experience intracerebral hemorrhage (ICH) is unclear. The prospective Japanese Adult Moyamoya trial randomized patients with adult-onset moyamoya disease and history of ICH to bilateral extracranial–intracranial direct bypass or conservative care. Eighty patients were enrolled (42 surgical; 38 nonsurgical). Adverse events causing significant morbidity were observed in 6 surgical patients (14.3%) and 13 nonsurgical patients (34.2%). Rebleeding was observed in 5 surgical patients (11.9%) and 12 nonsurgical patients (31.6%). Although only marginal in statistical significance, the surgical group showed decreased adverse events and rebleeding episodes, suggesting a direct bypass benefit. Further studies are needed to confirm whether these findings apply to non-Japanese moyamoya patients, and to determine the potential benefits for overall functional outcome.