title: Prediction of cerebral ischemic tolerance during carotid cross-clamping by angiographic criteria.
abstract: OBJECTIVE
  To evaluate the prognostic value of angiographic criteria and internal carotid artery (ICA) stump pressure for shunt placement in carotid surgery under local anaesthesia.
  
  
  METHODS
  Prospective clinical trial at a university hospital.
  
  
  METHODS
  In 120 patients a cerebral angiography was initiated before undergoing carotid surgery. Seventy-five percent of the patients were neurologically asymptomatic, 13% had transient ischaemic attacks and 12% suffered from previous strokes. The operation was exclusively performed under local anaesthesia and prior to cross-clamping the ICA stump-pressure was measured. A shunt was inserted only if hemispheric symptoms or unconsciousness occurred independent of the angiographic findings or stump pressure.
  
  
  RESULTS
  In 23% (27/120) a shunt became necessary and significantly (p<0.001) more often when there was a cross-flow towards the contralateral hemisphere (12/20=60%) or if the contralateral ICA was occluded (9/13=69%). The sensitivity for not needing a shunt in case of cross-flow towards the side of operation was 91% (52/57) whereas the specificity was 35% (22/63). ICA stump-pressure was significantly reduced in patients requiring a shunt (31 mmHg) compared to those not needing a shunt (53 mmHg) (p<0.001), but no definitive threshold value was found determining the need for shunting. Intraoperatively, no persistent neurological complication developed.
  
  
  CONCLUSIONS
  Angiographic cross-flow was a good, but not perfect predictor for the need of an intraoperative shunt.
authors.affiliation: Division for Vascular Surgery, Department of Visceral and Vascular Surgery, University of Cologne, Cologne, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Aleksic
authors.forename: M
authors.initials: M
authors.lastname: Gawenda
authors.forename: J
authors.initials: J
authors.lastname: Heckenkamp
authors.forename: V
authors.initials: V
authors.lastname: Matoussevitch
authors.forename: S
authors.initials: S
authors.lastname: Coburger
authors.forename: J
authors.initials: J
authors.lastname: Brunkwall
mesh_terms: D000368:Aged; D000772:Anesthesia, Local; D001166:Arteriovenous Shunt, Surgical; D001794:Blood Pressure; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000209:etiology*; D002343:Carotid Artery, Internal / Q000503:physiopathology; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007430:Intraoperative Care; D002546:Ischemic Attack, Transient / Q000209:etiology; D008297:Male; D015999:Multivariate Analysis; D011446:Prospective Studies; D020521:Stroke / Q000209:etiology