title: The value of cerebral angiography in predicting cerebral ischemia during carotid endarterectomy.
abstract: OBJECTIVE
  Temporary occlusion of the carotid artery during endarterectomy can result in ipsilateral cerebral ischemia if collateral blood flow is insufficient. This requires placement of a shunt across the carotid bifurcation, which is associated with increased operative risk. We retrospectively analyzed preoperative cerebral angiograms and intraoperative electroencephalographic recordings to determine if ischemia during carotid endarterectomy could be predicted from angiographic data.
  
  
  METHODS
  The cerebral angiograms of 30 patients were examined. Collateral blood flow to the hemisphere on the side of surgery was determined to be present if both proximal segments of the anterior cerebral artery and the anterior communicating artery were visualized, or if filling and washout of the ipsilateral posterior cerebral artery could be seen. Collateral flow was determined to be inadequate if the anterior collateral system was incomplete, and if either the ipsilateral posterior communicating artery was absent or the posterior cerebral artery filled without washout. This information was compared with intraoperative electroencephalographic and shunting data.
  
  
  RESULTS
  Of 15 patients who had demonstrable collateral blood flow, 14 had stable electroencephalograms and did not require a shunt during surgery. In all 15 patients in whom no collateral flow to the ipsilateral hemisphere could be shown, electroencephalographic changes prompted placement of an intraluminal shunt.
  
  
  CONCLUSIONS
  We found that the angiographic determination of inadequate collateral cerebral circulation correlated strongly with the development of intraoperative ischemia. This implies that routine preoperative cerebral angiograms can be used to alert the surgeon to the potential need for shunt placement during carotid endarterectomy.
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, MA.
authors.forename: R B
authors.initials: RB
authors.lastname: Schwartz
authors.forename: K M
authors.initials: KM
authors.lastname: Jones
authors.forename: G T
authors.initials: GT
authors.lastname: LeClercq
authors.forename: S S
authors.initials: SS
authors.lastname: Ahn
authors.forename: R
authors.initials: R
authors.lastname: Chabot
authors.forename: A
authors.initials: A
authors.lastname: Whittemore
authors.forename: J A
authors.initials: JA
authors.lastname: Mannick
authors.forename: M C
authors.initials: MC
authors.lastname: Donaldson
authors.forename: L D
authors.initials: LD
authors.lastname: Gugino
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000453:epidemiology* / Q000517:prevention & control; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003097:Collateral Circulation / Q000502:physiology; D004569:Electroencephalography; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012189:Retrospective Studies