title: The amount of solid cerebral microemboli during carotid stenting does not relate to the frequency of silent ischemic lesions.
abstract: OBJECTIVE
  Carotid artery stent placement (CAS) may be associated with clinically silent cerebral lesions. We prospectively evaluated the association of the number of solid cerebral microemboli during unprotected CAS with the frequency of silent cerebral lesions as detected by diffusion-weighted MR imaging (DWI).
  
  
  METHODS
  We performed multifrequency transcranial Doppler detection of solid microemboli in the ipsilateral middle cerebral artery (MCA) during CAS in 27 consecutive patients with symptomatic high-grade carotid stenoses. No embolus protection was used in any of the cases. DWI before and 24 +/- 2 hours after CAS was used to detect new ischemic lesions.
  
  
  RESULTS
  We detected 484 solid microemboli in 17 patients (63%). On MR imaging 24 +/- 2 hours after CAS, 6 patients (22%) had developed 13 new clinically silent DWI lesions within the ipsilateral MCA territory. In patients with Doppler evidence of solid emboli during CAS, the incidence of new DWI lesions was higher (29%) than in patients without Doppler evidence of solid emboli during the procedure (10%); this difference was not statistically significant (P = .25). The number of solid microemboli during CAS in patients with new ipsilateral DWI lesions was not significantly different from that in patients without new ipsilateral DWI lesions.
  
  
  CONCLUSIONS
  Solid microembolism is a common event during unprotected CAS; however, the frequency of procedure-related silent cerebral lesions appears to be independent of the number of solid cerebral microemboli during the procedure.
authors.affiliation: Department of Neurology, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Rosenkranz
authors.forename: J
authors.initials: J
authors.lastname: Fiehler
authors.forename: W
authors.initials: W
authors.lastname: Niesen
authors.forename: C
authors.initials: C
authors.lastname: Waiblinger
authors.forename: B
authors.initials: B
authors.lastname: Eckert
authors.forename: O
authors.initials: O
authors.lastname: Wittkugel
authors.forename: T
authors.initials: T
authors.lastname: Kucinski
authors.forename: J
authors.initials: J
authors.lastname: Röther
authors.forename: H
authors.initials: H
authors.lastname: Zeumer
authors.forename: C
authors.initials: C
authors.lastname: Weiller
authors.forename: U
authors.initials: U
authors.lastname: Sliwka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000628:therapy*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015607:Stents / Q000009:adverse effects*; D017585:Ultrasonography, Doppler, Transcranial