title: A prospective clinical study of cerebral microemboli and neuropsychological outcome comparing vent-line and auto-venting arterial line filters: both filters are equally safe.
abstract: BACKGROUND
  Microemboli are the main implicated cause of neuropsychological (NP) impairment after cardiac surgery. This prospective clinical trial compared the effect of an auto-venting arterial line filter on intraoperative cerebral microemboli and NP outcome compared to an arterial line filter with a vent line, in patients undergoing elective coronary artery bypass graft (CABG) surgery.
  
  
  METHODS
  One hundred and ten patients received either an Avecor Affinity (n =73) or Pall AV-6 (n =37) control filter. Cerebral microemboli during cardiopulmonary bypass were recorded by transcranial Doppler monitoring of the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a NP test battery (nine tests) administered 6-8 weeks postoperatively with their preoperative scores.
  
  
  RESULTS
  During cardiopulmonary bypass, the median number and range of microemboli were 67 (5-846) and 55 (2-773) for the Avecor and AV-6 groups, respectively (p = 0.47). There was no difference in NP outcome.
  
  
  CONCLUSIONS
  There is no difference in the filtering ability of vent-line and auto-vent filters as assessed by cerebral microemboli. This, together with the similar NP outcome, suggests that both types of filter are equally safe for clinical use.
authors.affiliation: Centre for Behavioural and Social Sciences in Medicine, University College London, UK.
authors.forename: Donald C
authors.initials: DC
authors.lastname: Whitaker
authors.forename: Jan
authors.initials: J
authors.lastname: Stygall
authors.forename: Chris
authors.initials: C
authors.lastname: Hope-Wynne
authors.forename: Robin K
authors.initials: RK
authors.lastname: Walesby
authors.forename: Michael J G
authors.initials: MJ
authors.lastname: Harrison
authors.forename: Stanton P
authors.initials: SP
authors.lastname: Newman
mesh_terms: D000368:Aged; D005112:Extracorporeal Circulation / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D009483:Neuropsychological Tests; D011446:Prospective Studies; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods