title: The dynamic air bubble trap reduces cerebral microembolism during cardiopulmonary bypass.
abstract: OBJECTIVE
  Neuropsychologic disorders are common after coronary artery bypass operations. Air microbubbles are identified as a contributing factor. A dynamic bubble trap might reduce the number of gaseous microemboli.
  
  
  METHODS
  A total of 50 patients undergoing coronary artery bypass operation were recruited for this study. In 26 patients a dynamic bubble trap was placed between the arterial filter and the aortic cannula (group 1), and in 24 patients a placebo dynamic bubble trap was used (group 2). The number of high-intensity transient signals within the proximal middle cerebral artery was continuously measured on both sides during bypass, which was separated into 4 periods: phase 1, start of bypass until aortic clamping; phase 2, aortic clamping until rewarming; phase 3, rewarming until clamp removal; and phase 4, clamp removal until end of bypass. S100 beta values were measured before, immediately after, and 6 and 48 hours after the operation and before hospital discharge.
  
  
  RESULTS
  The bubble elimination rate during bypass was 77% in group 1 and 28% in group 2 (P <.0001). The number of high-intensity signals was lower in group 1 during phase 1 (5.8 +/- 7.3 vs 16 +/- 15.4, P <.05 vs group 2) and phase 2 (6.9 +/- 7.3 vs 24.2 +/- 27.3, P <.05 vs group 2) but not during phases 3 and 4. Serum S100 beta values were equally increased in both groups immediately after the operation. Group 2 patients had higher S100 beta values 6 hours after the operation and significantly higher S100 beta values 48 hours after the operation (0.06 +/- 0.14 vs 0.18 +/- 0.24, P =.0133 vs group 2). Age and S100 beta values were correlated in group 2 but not in group 1.
  
  
  CONCLUSIONS
  Gaseous microemboli can be removed with a dynamic bubble trap. Subclinical cerebral injury detectable by increases of S100 beta disappears earlier after surgical intervention.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Kerckhoff-Klinik, Bad Nauheim, Germany. markus.schoenburg@kerckhoff.med.uni-giessen.de
authors.forename: M
authors.initials: M
authors.lastname: Schoenburg
authors.forename: B
authors.initials: B
authors.lastname: Kraus
authors.forename: A
authors.initials: A
authors.lastname: Muehling
authors.forename: U
authors.initials: U
authors.lastname: Taborski
authors.forename: H
authors.initials: H
authors.lastname: Hofmann
authors.forename: G
authors.initials: G
authors.lastname: Erhardt
authors.forename: S
authors.initials: S
authors.lastname: Hein
authors.forename: M
authors.initials: M
authors.lastname: Roth
authors.forename: P R
authors.initials: PR
authors.lastname: Vogt
authors.forename: G F
authors.initials: GF
authors.lastname: Karliczek
authors.forename: W-P
authors.initials: WP
authors.lastname: Kloevekorn
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D004569:Electroencephalography; D004618:Embolism, Air / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D007431:Intraoperative Complications / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010106:Oxygenators; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial