title: Endovascular treatment of intracranial microarteriovenous malformations.
abstract: OBJECTIVE
  Microarteriovenous malformations (micro-AVMs) are an uncommon subgroup of brain AVMs defined by a nidus measuring < 1 cm in diameter. The clinical features, angiographic characteristics, and outcomes in patients with micro-AVMs who had been treated endovascularly after presenting with hemorrhage were reviewed to identify common features affecting prognosis.
  
  
  METHODS
  Between 1997 and 2006, 25 patients (12 females and 13 males) with 26 micro-AVMs were treated. Twenty-four patients presented with intracerebral hematoma and 1 with subarachnoid hemorrhage only. All patients underwent CT on admission, diagnostic cerebral angiography, and 1 session of endovascular treatment during the acute phase.
  
  
  RESULTS
  Procedure-related complications occurred in 3 patients (12%), which caused temporary hemiparesis in 1 (4%) and no clinical sequelae in 2 patients (8%). Complete nidus obliteration was achieved at the end of the embolization in 22 (84.6%) of 26 lesions. Two recurrences were evident on follow-up angiography 6 months postembolization, resulting in a complete obliteration rate of 77% (20 of 26 lesions) after a single treatment. Late angiography was performed in 12 patients, and no further recurrences were identified.
  
  
  CONCLUSIONS
  Immediate complete obliteration of a micro-AVM with a high permanent cure and low morbidity rates was accomplished using endovascular treatment. Early embolization after bleeding should be considered as an alternative to resection.
authors.affiliation: Department of Neurosurgery & Interventional Neuroradiology, Hygeia Hospital, Athens, Greece.
authors.forename: Alexander
authors.initials: A
authors.lastname: Andreou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Ioannidis
authors.forename: Shivendra
authors.initials: S
authors.lastname: Lalloo
authors.forename: Nasis
authors.initials: N
authors.lastname: Nickolaos
authors.forename: James V
authors.initials: JV
authors.lastname: Byrne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002404:Catheterization / Q000379:methods*; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006406:Hematoma / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D016896:Treatment Outcome; D055815:Young Adult