title: Changes in blood flow of anterior and middle cerebral arteries following carotid endarterectomy: a transcranial Doppler study.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the changes in blood flow of anterior and middle cerebral arteries following carotid endarterectomy, using transcranial Doppler (TCD) flow studies.
  
  
  METHODS
  This study included 100 patients (72 men, mean age 65 years) who underwent carotid endarterectomy because of high-grade carotid stenosis or symptoms of ischemic stroke. Endarterectomy was performed by a distal shunt between the common carotid and internal carotid arteries. Blood flow in the anterior and middle cerebral arteries was assessed by TCD preoperatively and also in the postoperative period (1st and 4th day; 1st, 6th, and 12th month). Collateral circulation in the Willis circle was evaluated by common carotid compression.
  
  
  RESULTS
  Patients with bilateral carotid stenosis > or =70% exhibited a significantly increased flow velocity in the ipsilateral anterior cerebral artery (ACA), middle cerebral artery (MCA), and in the contralateral ACA. Patients with entirely occluded contralateral internal carotid artery showed the most pronounced changes in cerebral hemodynamics. Blood flow velocities returned to the preoperative values at 1 to 12 months following endarterectomy. Hyperperfusion syndrome was manifested in 14 patients, who exhibited significantly higher flow velocities in the ipsilateral MCA compared with asymptomatic patients.
  
  
  CONCLUSIONS
  A transient bilateral increase of blood flow velocity in the anterior part of the Willis circle may often occur in the immediate postoperative period following carotid endarterectomy. Although its clinical significance is not entirely understood, this increase may be associated with cerebral hyperperfusion syndrome.
authors.affiliation: Department of Vascular Surgery, General Hospital Georgios Gennimatas, Athens, Greece.
authors.forename: C K
authors.initials: CK
authors.lastname: Maltezos
authors.forename: N
authors.initials: N
authors.lastname: Papanas
authors.forename: T T
authors.initials: TT
authors.lastname: Papas
authors.forename: G S
authors.initials: GS
authors.lastname: Georgiadis
authors.forename: C K
authors.initials: CK
authors.lastname: Dragoumanis
authors.forename: J
authors.initials: J
authors.lastname: Marakis
authors.forename: E
authors.initials: E
authors.lastname: Maltezos
authors.forename: M K
authors.initials: MK
authors.lastname: Lazarides
mesh_terms: D000368:Aged; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001783:Blood Flow Velocity; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D002941:Circle of Willis / Q000503:physiopathology; D003097:Collateral Circulation; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D012720:Severity of Illness Index; D013577:Syndrome; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial