title: Association between posterior fossa arteriovenous malformations and prenidal aneurysm rupture: potential impact on management.
abstract: OBJECTIVE
  In patients with posterior fossa arteriovenous malformations (AVMs) who present with hemorrhage, feeding artery aneurysms are often the source of bleeding. The aim of this study was to evaluate the relative proportions of cases of infra- and supratentorial AVMs in which patients presented with prenidal aneurysm rupture. The management and outcome of 9 cases of posterior fossa AVMs associated with prenidal aneurysm rupture are presented.
  
  
  METHODS
  The authors retrospectively reviewed 233 consecutive AVM cases involving patients treated at their institution between April 2001 and August 2012. Patients with a prenidal aneurysm as the cause of the hemorrhage were identified. The frequencies of prenidal aneurysm-related ruptures were compared in cases of supra- and infratentorial AVMs. Management and clinical outcome (modified Rankin Scale [mRS] score) of patients with posterior fossa AVMs treated for ruptured prenidal aneurysms were recorded.
  
  
  RESULTS
  Of 233 AVMs, 25 (11%) were in the posterior fossa, and in 22 (88%) of these cases, the patients presented with hemorrhage, including 9 patients (41%) who presented with hemorrhage due to prenidal aneurysm rupture. Of 208 patients with supratentorial AVMs, 107 (51%) presented with hemorrhage, including 5 patients (4.7%) in whom the hemorrhage was associated with a prenidal aneurysm (p < 0.01). All 9 patients with posterior fossa AVMs and prenidal aneurysm rupture were treated with early embolization of the offending aneurysm. There was no early rebleeding or clinical complication related to this approach. At the end of follow-up (mean 46.8 months), 2 patients had an mRS score of 0, 1 had a score of 1, 3 had a score of 2, 2 patients were dead (mRS score of 6), and 1 patient was lost to follow-up.
  
  
  CONCLUSIONS
  Posterior fossa AVM hemorrhages are frequently associated with prenidal arterial aneurysms. Urgent endovascular treatment of the aneurysm was effective in this case series.
authors.affiliation: Department of Radiology, CHUM, Montréal, Québec, Canada.
authors.forename: Evgueni
authors.initials: E
authors.lastname: Kouznetsov
authors.forename: Alain
authors.initials: A
authors.lastname: Weill
authors.forename: Jimmy S
authors.initials: JS
authors.lastname: Ghostine
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Gentric
authors.forename: Jean
authors.initials: J
authors.lastname: Raymond
authors.forename: Daniel
authors.initials: D
authors.lastname: Roy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000150:complications* / Q000601:surgery*; D002648:Child; D003388:Cranial Fossa, Posterior / Q000473:pathology*; D019468:Disease Management; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000473:pathology / Q000601:surgery; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: AVM = arteriovenous malformation; PICA = posterior inferior cerebellar artery; arteriovenous malformation; cerebral AVM; embolization; mRS = modified Rankin Scale; posterior fossa AVM; prenidal aneurysm