title: Treatment of dissecting aneurysms of the PICA: anatomical considerations and clinical outcome.
abstract: OBJECTIVE
  Posterior inferior cerebellar artery (PICA) dissecting aneurysms require rapid and aggressive treatment by sacrificing the parent vessel of the aneurysm-bearing dissected vessel. We assessed the clinical consequences of PICA occlusion in view of the local vascular anatomy.
  
  
  METHODS
  We performed a retrospective search of our neurovascular database in the period 2007-2012. Patient characteristics, including clinical presentation, WFNS (World Federation of Neurosurgical Societies) grading and Glasgow Outcome Scale (GOS), were recorded. CT and CT angiographic findings as well as the detailed vascular anatomy including collateral circulation were assessed.
  
  
  RESULTS
  We identified 10 patients (5 male; mean age 50 years). Eight patients presented with WFNS grade I and II, one with grade IV and one with grade V. All patients were treated with parent vessel occlusion (PVO). An extradural PICA origin was seen in three patients. Collateral circulation was visible before PVO in two and after PVO in seven additional patients. Despite the presence of collaterals, mild cerebellar ischemia occurred in three patients, without development of a Wallenberg syndrome. Outcome was favorable in 9 patients (8 patients GOS 5, one patient GOS 4). One patient died due to the mass effect of the initial cerebellar hematoma.
  
  
  CONCLUSIONS
  PVO to treat PICA dissecting aneurysms was well tolerated with a 90% favorable outcome. Regional collateral circulation and vascular variations permitted relative safe vessel occlusion with only minor cerebellar symptoms in this small group of patients.
authors.affiliation: Department of Radiology, C1-210, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. Electronic address: r.vdberg@amc.uva.nl.
authors.forename: René
authors.initials: R
authors.lastname: van den Berg
authors.affiliation: Neurosurgical Center Amsterdam, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Tom C
authors.initials: TC
authors.lastname: Doorschodt
authors.affiliation: Department of Radiology, C1-210, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Marieke E S
authors.initials: ME
authors.lastname: Sprengers
authors.affiliation: Neurosurgical Center Amsterdam, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: W Peter
authors.initials: WP
authors.lastname: Vandertop
mesh_terms: D000328:Adult; D000784:Aortic Dissection / Q000000981:diagnostic imaging* / Q000628:therapy*; D002533:Cerebral Angiography / Q000379:methods; D004621:Embolization, Therapeutic / Q000379:methods; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy*; D014854:Lateral Medullary Syndrome / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
keywords: Anatomy; Clinical outcome; Dissecting aneurysm; Embolization; Parent vessel occlusion; Posterior inferior cerebellar artery