title: Status of the circle of Willis and intolerance to carotid cross-clamping during carotid endarterectomy.
abstract: OBJECTIVE
  During carotid endarterectomy (CEA), an intolerance to the cross-clamping (CC) can occur. The purpose of this study was to evaluate whether preoperative magnetic resonance angiography (MRA) can predict CC intolerance.
  
  
  METHODS
  Seventy-one patients (57 males, 14 females, mean age 71.8 years, age range 46-86 years) underwent 71 CEA procedures under local anaesthesia. Before CEA, patients underwent an MRA of the Circle of Willis (CoW) and were then classified into three groups: group A consisted of patients with a complete CoW, group B included patients with one agenesia/obstruction in the CoW and group C comprised patients with two or more agenesiae/obstructions in the CoW. The association between the number of anatomical variants in the CoW, corrected for the status of the contralateral carotid artery, and the onset of CC intolerance was evaluated.
  
  
  RESULTS
  The prevalence of intolerance to CC was 15.5% (11/71). The Fisher test and logistic regression analysis showed a statistically significant association between the intolerance to CC and two or more agenesiae/obstructions in the CoW (p value < 0.00001 and p < 0.001, respectively). No neurological complications were observed.
  
  
  CONCLUSIONS
  The results of our study showed that two or more agenesiae/obstructions of the CoW identified by MRA were associated with a high risk of intolerance to CC during CEA.
authors.affiliation: Vascular Surgery, Department of Surgical Sciences, Cagliari University, Cagliari, Italy. roberto.montisci@iol.it
authors.forename: R
authors.initials: R
authors.lastname: Montisci
authors.forename: R
authors.initials: R
authors.lastname: Sanfilippo
authors.forename: R
authors.initials: R
authors.lastname: Bura
authors.forename: C
authors.initials: C
authors.lastname: Branca
authors.forename: M
authors.initials: M
authors.lastname: Piga
authors.forename: L
authors.initials: L
authors.lastname: Saba
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D016893:Carotid Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D020785:Central Nervous System Vascular Malformations / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D016009:Chi-Square Distribution; D002941:Circle of Willis / Q000002:abnormalities* / Q000503:physiopathology; D003250:Constriction; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006801:Humans; D016015:Logistic Models; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011300:Preoperative Care; D018570:Risk Assessment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex