title: Cerebral microembolism during carotid endarterectomy.
abstract: BACKGROUND
  This study was designed to assess the intraoperative risk of cerebral microembolism, as detected by transcranial Doppler ultrasonography, during carotid endarterectomy.
  
  
  METHODS
  Thirty-six patients (37 procedures) with symptomatic (n = 35) or asymptomatic (n = 2) internal carotid artery origin stenosis(> 50%) were monitored continuously during carotid endarterectomy. Special instrumentation was used to detect high-intensity transient signals (HITS) in the middle cerebral artery on the carotid endarterectomy side. All HITS satisfied a priori established criteria.
  
  
  RESULTS
  The incidence of carotid endarterectomies with formed-element HITS increased at clamp release (23/37, P < 0.001) and shunt opening (7/11, P = 0.014), and during wound closure (13/22, P< 0.005) and shunting (5/11, P = 0.046). HITS with air microbubble characteristics were detected at clamp release (22/37, P < 0.001) and shunt opening (5/11, P = 0.025).
  
  
  CONCLUSIONS
  HITS do not occur randomly during carotid endarterectomy. Shunting, unclamping, and wound closure are high-risk periods.
authors.affiliation: Department of Neurology, Boston University School of Medicine, Massachusetts, USA.
authors.forename: T
authors.initials: T
authors.lastname: Gavrilescu
authors.forename: V L
authors.initials: VL
authors.lastname: Babikian
authors.forename: N L
authors.initials: NL
authors.lastname: Cantelmo
authors.forename: R
authors.initials: R
authors.lastname: Rosales
authors.forename: V
authors.initials: V
authors.lastname: Pochay
authors.forename: M
authors.initials: M
authors.lastname: Winter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000150:complications / Q000000981:diagnostic imaging*; D007431:Intraoperative Complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler