title: Management Outcome of Brainstem Arteriovenous Malformations: The Role of Radiosurgery.
abstract: BACKGROUND
  Management decisions for brainstem arteriovenous malformations (AVMs) are complicated by balancing the risks of treatment and natural progression to hemorrhage. The present study seeks to compare radiosurgery and conservative management outcomes in brainstem AVMs.
  
  
  METHODS
  We performed a retrospective review of patients with brainstem AVM seen at our institution from 1990 to 2013. Patients missing baseline information or those lost to follow-up were excluded. Clinical and angiographic characteristics and subsequent hemorrhagic risk were evaluated according to brainstem AVM location and treatment modality.
  
  
  RESULTS
  We identified 30 patients with brainstem AVM with complete data. Mean age was 41.6 ± 20.3 years, and 53.3% (n = 16) were male. Sixteen (53.3%) presented with hemorrhage. Twelve patients (40.0%) were conservatively managed, and 18 were treated. Sixteen (88.9%) of the treated patients underwent radiosurgery, 1 (5.6%) underwent surgery, and 1 (5.6%) underwent embolization only. Average follow-up period was 4.7 ± 5.7 years, and 5 patients (16.7%) experienced recurrent hemorrhage, 3 of whom were in the radiosurgery group and 2 in the conservative group, giving an annual recurrent hemorrhage risk of 3.7% and 4.8%, respectively. Lesion obliteration was achieved in 8 patients (26.7%). Baseline clinical and angiographic factors were similar between the radiosurgery and conservative group. Obliteration was achieved in 43.8% of those treated with radiosurgery (P = 0.008). Despite similar baseline modified Rankin Scale scores, more patients had improvement of modified Rankin Scale score at last follow-up in the radiosurgery group (P = 0.004). Recurrent hemorrhage during follow-up was similar between the 2 groups (P = 0.887).
  
  
  CONCLUSIONS
  Our results suggest that when patients with brainstem AVM are selected cautiously, radiosurgery may achieve obliteration and symptom relief without increasing subsequent hemorrhage risk.
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Wuyang
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Porras
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Tomas
authors.initials: T
authors.lastname: Garzon-Muvdi
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Risheng
authors.initials: R
authors.lastname: Xu
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Caplan
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Alice L
authors.initials: AL
authors.lastname: Hung
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Braileanu
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Rong
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Geoffrey P
authors.initials: GP
authors.lastname: Colby
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Coon
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Tamargo
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. Electronic address: jhuang24@jhmi.edu.
authors.forename: Judy
authors.initials: J
authors.lastname: Huang
mesh_terms: D000328:Adult; D001933:Brain Stem / Q000098:blood supply*; D015331:Cohort Studies; D000072700:Conservative Treatment; D016208:Databases, Factual; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000628:therapy*; D020300:Intracranial Hemorrhages / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D016634:Radiosurgery / Q000379:methods*; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: Arteriovenous malformation; Brainstem; Functional Outcome; Radiosurgery