title: Role of surgery in the management of brain arteriovenous malformations: prospective cohort study.
abstract: OBJECTIVE
  Management of brain arteriovenous malformation (bAVM) is controversial. We have analyzed the largest surgical bAVM cohort for outcome.
  
  
  METHODS
  Both operated and nonoperated cases were included for analysis. A total of 779 patients with bAVMs were consecutively enrolled between 1989 and 2014. Initial management recommendations were recorded before commencement of treatment. Surgical outcome was prospectively recorded and outcomes assigned at the last follow-up visit using modified Rankin Scale. First, a sensitivity analyses was performed to select a subset of the entire cohort for which the results of surgery could be generalized. Second, from this subset, variables were analyzed for risk of deficit or near miss (intraoperative hemorrhage requiring blood transfusion of ≥2.5 L, hemorrhage in resection bed requiring reoperation, and hemorrhage associated with either digital subtraction angiography or embolization).
  
  
  RESULTS
  A total of 7.7% of patients with Spetzler-Ponce classes A and B bAVM had an adverse outcome from surgery leading to a modified Rankin Scale >1. Sensitivity analyses that demonstrated outcome results were not subject to selection bias for Spetzler-Ponce classes A and B bAVMs. Risk factors for adverse outcomes from surgery for these bAVMs include size, presence of deep venous drainage, and eloquent location. Preoperative embolization did not affect the risk of perioperative hemorrhage.
  
  
  CONCLUSIONS
  Most of the ruptured and unruptured low and middle-grade bAVMs (Spetzler-Ponce A and B) can be surgically treated with a low risk of permanent morbidity and a high likelihood of preventing future hemorrhage. Our results do not apply to Spetzler-Ponce C bAVMs.
authors.affiliation: From the Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia (M.K., N.A., M.K.M.); Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland (M.K.); and Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland (D.B.).
authors.forename: Miikka
authors.initials: M
authors.lastname: Korja
authors.affiliation: From the Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia (M.K., N.A., M.K.M.); Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland (M.K.); and Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland (D.B.).
authors.forename: David
authors.initials: D
authors.lastname: Bervini
authors.affiliation: From the Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia (M.K., N.A., M.K.M.); Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland (M.K.); and Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland (D.B.).
authors.forename: Nazih
authors.initials: N
authors.lastname: Assaad
authors.affiliation: From the Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia (M.K., N.A., M.K.M.); Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland (M.K.); and Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland (D.B.). michael.morgan@mq.edu.au.
authors.forename: Michael Kerin
authors.initials: MK
authors.lastname: Morgan
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: arteriovenous malformations; brain; cohort studies; neurosurgery; risk factors; treatment outcome