title: Extracranial blood flow distribution during carotid surgery.
abstract: OBJECTIVE
  The collateral function of the external carotid artery (ECA) for cerebral perfusion in cases of atherosclerotic occlusive disease of the internal carotid artery (ICA) is difficult to assess; for this reason, blood flow measurements were taken during carotid endarterectomy (CEA).
  
  
  METHODS
  Blood flow was measured before and after CEA using a transit-time flow meter at the carotid artery in 1000 patients who underwent CEA for high-degree (>70%) ICA stenosis. The data were collected prospectively and analysed retrospectively.
  
  
  RESULTS
  Median ICA blood flow increased significantly, up 46% from 160 ml min(-1) (IQR: 100-234 ml min(-1)) before CEA to 240 ml min(-1) (IQR: 187-309 ml min(1)) after CEA (P<0.001). Median ECA blood flow dropped by 4%, from 152 ml min(-1) (IQR: 108-220 ml min(-1)) to 150 ml min(-1) (IQR: 103-200 ml min(-1)) (P=0.001). Relative ICA blood flow volumes related to common carotid artery (CCA) flow increased from 58% before CEA to 73% after CEA, whereas relative ECA flow decreased from 54% to 44%.
  
  
  CONCLUSIONS
  Increased blood flow in the ICA after CEA is accompanied by decreased ECA flow whereupon the absolute amount of this redistribution is relatively limited. A more profound evaluation of these haemodynamic conditions demands further study.
authors.affiliation: Department of Vascular Surgery, University Clinic of Cologne, Cologne, Germany. aleksicm@kliniken-koeln.de
authors.forename: M
authors.initials: M
authors.lastname: Aleksic
authors.forename: J
authors.initials: J
authors.lastname: Brunkwall
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D002342:Carotid Artery, External / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000503:physiopathology / Q000601:surgery*; D016893:Carotid Stenosis / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D003097:Collateral Circulation; D016894:Endarterectomy, Carotid / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome