title: Assessment of reverse flow as a means of cerebral protection during carotid artery stent placement with diffusion-weighted and transcranial Doppler imaging.
abstract: OBJECTIVE
  To assess the effectiveness of flow reversal as an alternative means of cerebral protection by using transcranial Doppler recordings and diffusion-weighted imaging (DWI) as surrogate markers of brain injury.
  
  
  METHODS
  Eighteen patients with symptomatic carotid artery disease were recruited. Magnetic resonance imaging was performed before the intervention and at 3 and 24 hours and 30 days after the intervention to detect new ischemic lesions with DWI. Transcranial Doppler recordings were made during the procedure to assess for microembolic signals (MESs). Data were compared against data from a historical control cohort of patients who underwent CAS placement with or without filter protection (n = 15 each) under the same protocol in a different study.
  
  
  RESULTS
  There were fewer periprocedural new lesions on DWI in the reverse-flow cohort compared with the historical control cohort with filter protection (P = .084). Reverse flow revealed significantly fewer MESs during the whole procedure compared with the filter-protected group (P = .01) but not the unprotected group (P = .55). There was a marked decrease in MES counts for reverse flow protection during the embologenic stages of the procedure (P = .004).
  
  
  CONCLUSIONS
  Use of the reverse flow device was associated with fewer overall lesions on DWI and proportionately fewer positive scans compared with the use of filter-type devices (P = .08, not significant). Transcranial Doppler recordings demonstrated a significant reduction in embolization to the brain during carotid artery stent placement with the use of reverse-flow cerebral protection.
authors: Sheffield Vascular Institute, Northern General Hospital, Herries Road, Sheffield, United Kingdom. s.goode@sheffield.ac.uk
authors: Stephen D
authors: SD
authors: Goode
authors: Nigel
authors: N
authors: Hoggard
authors: Sumaira
authors: S
authors: Macdonald
authors: David H
authors: DH
authors: Evans
authors: Trevor J
authors: TJ
authors: Cleveland
authors: Peter A
authors: PA
authors: Gaines
mesh_terms: D000368:Aged; D017130:Angioplasty / Q000009:adverse effects / Q000295:instrumentation*; D002545:Brain Ischemia / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D002340:Carotid Artery Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D002560:Cerebrovascular Circulation; D038524:Diffusion Magnetic Resonance Imaging; D057505:Embolic Protection Devices; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010477:Perfusion / Q000379:methods*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial