title: Perianeurysmal edema in giant intracranial aneurysms in relation to aneurysm location, size, and partial thrombosis.
abstract: OBJECTIVE
  The underlying mechanisms causing intracranial perianeurysmal edema (PAE) are still poorly understood. Since PAE is most frequently observed in giant intracranial aneurysms (GIAs), the authors designed a study to examine the occurrence of PAE in relation to the location, size, and partial thrombosis (PT) of GIAs along with the clinical impact of PAE.
  
  
  METHODS
  Magnetic resonance imaging data for patients with a diagnosis of unruptured GIA from the international multicenter Giant Intracranial Aneurysm Registry were retrospectively analyzed with regard to location and size of the GIA, PAE volume, and the presence of PT. The occurrence of PAE was correlated to clinical findings.
  
  
  RESULTS
  Imaging data for 69 GIAs were eligible for inclusion in this study. Perianeurysmal edema was observed in 33.3% of all cases, with the highest frequency in GIAs of the middle cerebral artery (MCA; 68.8%) and the lowest frequency in GIAs of the cavernous internal carotid artery (ICA; 0.0%). Independent predictors of PAE formation were GIA volume (OR 1.13, p = 0.02) and the occurrence of PT (OR 9.84, p = 0.04). Giant intracranial aneurysm location did not predict PAE occurrence. Giant aneurysms with PAE were larger than GIAs without PAE (p < 0.01), and GIA volume correlated with PAE volume (rs = 0.51, p = 0.01). Perianeurysmal edema had no influence on the modified Rankin Scale score (p = 0.30 or the occurrence of aphasia (p = 0.61) or hemiparesis (p = 0.82).
  
  
  CONCLUSIONS
  Perianeurysmal edema was associated with GIA size and the presence of PT. As no PAE was observed in cavernous ICA aneurysms, even though they exerted mass effect on the brain and also displayed PT, the dura mater may serve as a barrier protecting the brain from PAE formation.
authors.affiliation: Department of Neurosurgery, Charité-Universitaetsmedizin Berlin;
authors.forename: Julius
authors.initials: J
authors.lastname: Dengler
authors.affiliation: Department of Neurosurgery, Charité-Universitaetsmedizin Berlin;
authors.forename: Nicolai
authors.initials: N
authors.lastname: Maldaner
authors.affiliation: Service de Neurochirurgie, Faculté de Médecine de Genève and Hôpitaux Universitaire de Genève; and.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bijlenga
authors.affiliation: Department of Neurosurgery, University Hospital of Zurich, Switzerland.
authors.forename: Jan-Karl
authors.initials: JK
authors.lastname: Burkhardt
authors.affiliation: Department of Neurosurgery, Unfallkrankenhaus Berlin;
authors.forename: Alexander
authors.initials: A
authors.lastname: Graewe
authors.affiliation: Department of Neurosurgery, University of Greifswald;
authors.forename: Susanne
authors.initials: S
authors.lastname: Guhl
authors.affiliation: Department of Neurosurgery, Hannover Medical School, Hannover;
authors.forename: Bujung
authors.initials: B
authors.lastname: Hong
authors.affiliation: Department of Neurosurgery, BG Hospital Bergmannstrost, Halle;
authors.forename: Christian
authors.initials: C
authors.lastname: Hohaus
authors.affiliation: Department of Neurosurgery and Interventional Neuroradiology, Klinikum Deggendorf;
authors.forename: Adisa
authors.initials: A
authors.lastname: Kursumovic
authors.affiliation: Department of Neurosurgery, Georg-August-University Goettingen;
authors.forename: Dorothee
authors.initials: D
authors.lastname: Mielke
authors.affiliation: Department of Neurosurgery, University of Regensburg;
authors.forename: Karl-Michael
authors.initials: KM
authors.lastname: Schebesch
authors.affiliation: Department of Neurosurgery, Technical University of Munich;
authors.forename: Maria
authors.initials: M
authors.lastname: Wostrack
authors.affiliation: Zentrum fuer Neuroradiologie, Clinic Hirslanden, Zurich;
authors.forename: Daniel
authors.initials: D
authors.lastname: Rufenacht
authors.affiliation: Department of Neurosurgery, Charité-Universitaetsmedizin Berlin;
authors.forename: Peter
authors.initials: P
authors.lastname: Vajkoczy
authors.affiliation: Department of Neurosurgery, University Medical Center, Hamburg Eppendorf, Germany;
authors.forename: Nils Ole
authors.initials: NO
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D000368:Aged; D001929:Brain Edema / Q000150:complications* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013927:Thrombosis / Q000150:complications* / Q000473:pathology / Q000601:surgery
keywords: ACA = anterior cerebral artery; GIA = giant intracranial aneurysm; ICA = internal carotid artery; ICH = intracerebral hemorrhage; MCA = middle cerebral artery; PAE = perianeurysmal edema; PT = partial thrombosis; aneurysm volume; giant intracranial aneurysm; mRS = modified Rankin Scale; partially thrombosed aneurysm; perianeurysmal edema; vascular disorders