title: Extra-intracranial blood shunt mimicking aneurysm rupture: intracranial-pressure-controlled rabbit subarachnoid hemorrhage model.
abstract: BACKGROUND
  The achieved degree of delayed cerebral vasospasm (DCVS) in the rabbits most frequently applied cistern magna blood injection model is often mild. The aim of this study was to characterize and evaluate the feasibility of an experimental SAH technique that mimics pathophysiological mechanisms and triggers higher degrees of DCVS.
  
  
  METHODS
  SAH was induced by extracranial-intracranial (EC/IC) shunting of blood from the subclavian artery into the great cerebral cistern. Intracranial pressure (ICP), arterial blood pressure, heart rate, arterial blood gas analysis, and neurological status were monitored throughout the experiments. The magnitude of spasm was determined by comparison of pre-SAH (day 0) and post-SAH (day 3) angiograms and postmortem morphometric analysis of the basilar artery.
  
  
  RESULTS
  A total of 13 experiments (SAH, n=11; controls, n=2) were performed. Two animals died after initiation of the EC/IC blood shunt in respiratory arrest. In SAH animals, ICP (baseline: 12+/-1 [mean+/-SD]; peak: 51+/-4; steady-state level: 15+/-2 mm Hg) rose to diastolic blood pressure levels (56+/-3 mm Hg) within 98+/-20s, and fell to a steady state within 186+/-41 s. SAH-induced vasoconstriction of the basilar artery was 53.1+/-2.8% on day 3 compared to baseline (P<0.05) and histology confirmed marked vasoconstriction.
  
  
  CONCLUSIONS
  This novel technique of SAH induction closely mimics the pathophysiological sequelae of aneurysm rupture and triggers constant higher degrees of delayed cerebral vasospasm than previously described rabbit models. The severity of vasospasm attained offers a unique opportunity to evaluate future therapeutic treatment options.
authors.affiliation: Department of Intensive Care Medicine, Bern University Hospital and University of Bern, 3010 Bern, Switzerland. serge.marbacher@ksa.ch
authors.forename: Serge
authors.initials: S
authors.lastname: Marbacher
authors.forename: Camillo
authors.initials: C
authors.lastname: Sherif
authors.forename: Volker
authors.initials: V
authors.lastname: Neuschmelting
authors.forename: Janine-Ai
authors.initials: JA
authors.lastname: Schläppi
authors.forename: Jukka
authors.initials: J
authors.lastname: Takala
authors.forename: Stephan M
authors.initials: SM
authors.lastname: Jakob
authors.forename: Javier
authors.initials: J
authors.lastname: Fandino
mesh_terms: D000818:Animals; D002533:Cerebral Angiography / Q000379:methods; D002548:Cerebral Revascularization / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D005260:Female; D007091:Image Processing, Computer-Assisted / Q000379:methods; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D007427:Intracranial Pressure / Q000502:physiology*; D011817:Rabbits; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis / Q000503:physiopathology*; D013346:Subarachnoid Space / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D013348:Subclavian Artery / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D020301:Vasospasm, Intracranial / Q000209:etiology / Q000503:physiopathology*