title: Effects of extracranial-intracranial bypass for patients with hemorrhagic moyamoya disease: results of the Japan Adult Moyamoya Trial.
abstract: OBJECTIVE
  About one half of those who develop adult-onset moyamoya disease experience intracranial hemorrhage. Despite the extremely high frequency of rebleeding attacks and poor prognosis, measures to prevent rebleeding have not been established. The purpose of this study is to determine whether extracranial-intracranial bypass can reduce incidence of rebleeding and improve patient prognosis.
  
  
  METHODS
  This study was a multicentered, prospective, randomized, controlled trial conducted by 22 institutes in Japan. Adult patients with moyamoya disease who had experienced intracranial hemorrhage within the preceding year were given either conservative care or bilateral extracranial-intracranial direct bypass and were observed for 5 years. Primary and secondary end points were defined as all adverse events and rebleeding attacks, respectively.
  
  
  RESULTS
  Eighty patients were enrolled (surgical, 42; nonsurgical, 38). Adverse events causing significant morbidity were observed in 6 patients in the surgical group (14.3%) and 13 patients in the nonsurgical group (34.2%). Kaplan-Meier survival analysis revealed significant differences between the 2 groups (3.2%/y versus 8.2%/y; P=0.048). The hazard ratio of the surgical group calculated by Cox regression analysis was 0.391 (95% confidence interval, 0.148-1.029). Rebleeding attacks were observed in 5 patients in the surgical group (11.9%) and 12 in the nonsurgical group (31.6%), significantly different in the Kaplan-Meier survival analysis (2.7%/y versus 7.6%/y; P=0.042). The hazard ratio of the surgical group was 0.355 (95% confidence interval, 0.125-1.009).
  
  
  CONCLUSIONS
  Although statistically marginal, Kaplan-Meier analysis revealed the significant difference between surgical and nonsurgical group, suggesting the preventive effect of direct bypass against rebleeding.
  
  
  BACKGROUND
  http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000166.
authors.affiliation: From the Department of Neurosurgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan (S.M., J.C.T.); Southern TOHOKU Research Institute for Neuroscience, Koriyama, Japan (T.Y.); National Cerebral and Cardiovascular Center, Suita, Japan (N.H.); Department of Cerebrovascular Disease and Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan (Y.O.); Departments of Public Health (I.T.) and Neurosurgery (T.T.), Tohoku University Graduate School of Medicine, Sendai, Japan; and Integrative Stroke Imaging Center, National Cerebral and Cardiovascular Center, Suita, Japan (J.N.).
authors.forename: Susumu
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hashimoto
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Okada
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuji
authors.forename: Teiji
authors.initials: T
authors.lastname: Tominaga
authors.forename: Jyoji
authors.initials: J
authors.lastname: Nakagawara
authors.forename: Jun C
authors.initials: JC
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D002543:Cerebral Hemorrhage / Q000209:etiology / Q000517:prevention & control*; D002548:Cerebral Revascularization / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000150:complications / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D055502:Secondary Prevention; D016896:Treatment Outcome
keywords: cerebral revascularization; hemorrhage; moyamoya disease