title: Cerebral arterial fenestrations: a common phenomenon in unexplained subarachnoid haemorrhage.
abstract: BACKGROUND
  Fenestrations of intracranial arteries are variants resulting from incomplete fusion of vessels during development with unknown clinical significance. They are best visualised with 3D rotational angiography (3DRA).
  
  
  OBJECTIVE
  In a prospective consecutive series of patients with suspected aneurysms, 3DRA was performed to identify not only the potential bleeding source but also to assess the frequency and location of any fenestrations of intracranial arteries.
  
  
  METHODS
  In 287 consecutive patients with possible intracranial aneurysms (accidental discovery or previous history of SAH), 3DRAs were prospectively performed, and the location of subarachnoid haemorrhage was assessed by CT.
  
  
  RESULTS
  Of 174 patients presenting with SAH, 153 had saccular aneurysms, and in 21 cases (12.1 %), no source of bleeding was found. In 20 of these 21 patients with "unexplained SAH" (95.2 %) an arterial fenestration was detected in the neighbourhood of the clot. The incidence of fenestration in the 153 aneurysmal SAH patients was 22.9 %, and it was 23.3 % in 266 patients with intracranial aneurysms (113 accidental and 153 ruptured).
  
  
  CONCLUSIONS
  Arterial fenestration was detected in 22.9 % of ruptured cerebral aneurysms, in contrast with 95.2 % in patients with unexplained SAH, the difference being statisctically significant (p < 0.01). Fenestration is a developmental defect, a structural wall weakness possibly making the vessel prone to rupture. Its incidence of nearly 100 % may suggest a connection with idiopathic SAH. The presented data indicate that arterial fenestrations are generally overlooked, and they can be considered as one of the candidates for the source of idiopathic SAH.
authors.affiliation: Department of Neurosurgery, University of Pécs, 2 Ret str, 7623, Pécs, Hungary.
authors.forename: Istvan
authors.initials: I
authors.lastname: Hudák
authors.forename: Gabor
authors.initials: G
authors.lastname: Lenzsér
authors.forename: Veronika
authors.initials: V
authors.lastname: Lunenkova
authors.forename: Tamás
authors.initials: T
authors.lastname: Dóczi
mesh_terms: D017542:Aneurysm, Ruptured / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000002:abnormalities*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D015994:Incidence; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D008297:Male; D011446:Prospective Studies; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy