title: Impact of bubble size in a rat model of cerebral air microembolization.
abstract: BACKGROUND
  Cerebral air microembolization (CAM) is a frequent side effect of diagnostic or therapeutic interventions. Besides reduction of the amount of bubbles, filter systems in the clinical setting may also lead to a dispersion of large gas bubbles and therefore to an increase of the gas-liquid-endothelium interface. We evaluated the production and application of different strictly defined bubble diameters in a rat model of CAM and assessed functional outcome and infarct volumes in relation to the bubble diameter.
  
  
  METHODS
  Gas emboli of defined number and diameter were injected into the carotid artery of rats. Group I (n = 7) received 1800 air bubbles with a diameter of 45 μm, group II (n = 7) 40 bubbles of 160 μm, controls (n = 6) saline without gas bubbles; group I and II yielded the same total injection volume of air with 86 nl. Functional outcome was assessed at baseline, after 4 h and 24 h following cerebral MR imaging and infarct size calculation.
  
  
  RESULTS
  Computer-aided evaluation of bubble diameters showed high constancy (group I: 45.83 μm ± 2.79; group II: 159 μm ± 1.26). Animals in group I and II suffered cerebral ischemia and clinical deterioration without significant difference. Infarct sizes did not differ significantly between the two groups (p = 0.931 u-test).
  
  
  CONCLUSIONS
  We present further development of a new method, which allows reliable and controlled CAM with different bubble diameters, producing neurological deficits due to unilateral cerebral damage. Our findings could not display a strong dependency of stroke frequency and severity on bubble diameter.
authors.forename: Martin
authors.initials: M
authors.lastname: Juenemann
authors.forename: Mesut
authors.initials: M
authors.lastname: Yeniguen
authors.forename: Nadine
authors.initials: N
authors.lastname: Schleicher
authors.forename: Johannes
authors.initials: J
authors.lastname: Blumenstein
authors.forename: Max
authors.initials: M
authors.lastname: Nedelmann
authors.forename: Marlene
authors.initials: M
authors.lastname: Tschernatsch
authors.forename: Georg
authors.initials: G
authors.lastname: Bachmann
authors.forename: Manfred
authors.initials: M
authors.lastname: Kaps
authors.forename: Petr
authors.initials: P
authors.lastname: Urbanek
authors.forename: Markus
authors.initials: M
authors.lastname: Schoenburg
authors.affiliation: Department of Neurology, Justus-Liebig-University Giessen, Giessen, Germany. Tibo.Gerriets@neuro.med.uni-giessen.de.
authors.forename: Tibo
authors.initials: T
authors.lastname: Gerriets
mesh_terms: D000818:Animals; D002315:Cardiopulmonary Bypass; D002544:Cerebral Infarction / Q000209:etiology* / Q000473:pathology; D004195:Disease Models, Animal; D004618:Embolism, Air / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar