title: Preoperative cerebral hemodynamics and shunting during carotid endarterectomy in patients with severe unilateral carotid stenosis.
abstract: OBJECTIVE
  To estimate the possible predictors for the need for shunting during carotid endarterectomy in patients with severe unilateral carotid stenosis based on preoperative transcranial Doppler sonographic examination.
  
  
  METHODS
  One hundred twenty-six patients were included in the study. Pulsatility index, flow acceleration, peak systolic velocity, and mean velocity were measured in the middle cerebral artery (MCA) and anterior cerebral artery on both sides. Cerebrovascular reactivity (CVR) was evaluated in 21 patients with shunts and in 55 patients without shunts.
  
  
  RESULTS
  The shunted and nonshunted groups did not differ with regard to demographic and clinical characteristics. The side-to-side difference in peak systolic velocity and mean velocity of the MCA was significantly higher in patients with shunts. CVR were significantly higher in the patients without shunts (36.0 +/- 17.2%) than in patients with shunts (16.6 +/- 11.4%; p = 0.0003). The peak systolic velocity and mean velocity asymmetry of the MCA had relatively low receiver operating characteristics, whereas CVR exhibited a relatively high accuracy in predicting the need for shunting.
  
  
  CONCLUSIONS
  Low CVR and increased asymmetry of MCA velocities were found in patients who subsequently required shunting during carotid endarterectomy. The relatively low accuracy of the MCA asymmetry should prevent the use of this criterion as a reliable preoperative predictor for shunting during carotid surgery, whereas CVR was more accurate and may prove useful in this setting.
authors.affiliation: Department of Neurology, Rambam Medical Center and Technion Faculty of Medicine, Haalija Street 8, Haifa 32801, Israel.
authors.forename: Gregory
authors.initials: G
authors.lastname: Telman
authors.forename: Efim
authors.initials: E
authors.lastname: Kouperberg
authors.forename: Sami
authors.initials: S
authors.lastname: Nitecki
authors.forename: Toni
authors.initials: T
authors.lastname: Karram
authors.forename: Henry A
authors.initials: HA
authors.lastname: Schwarz
authors.forename: Elliot
authors.initials: E
authors.lastname: Sprecher
authors.forename: Aaron
authors.initials: A
authors.lastname: Hoffman
authors.forename: David
authors.initials: D
authors.lastname: Yarnitsky
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging; D050197:Atherosclerosis / Q000601:surgery; D001783:Blood Flow Velocity / Q000502:physiology; D002339:Carotid Arteries / Q000601:surgery; D016893:Carotid Stenosis / Q000601:surgery*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D016894:Endarterectomy, Carotid; D005260:Female; D005544:Forecasting; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D011183:Postoperative Complications; D011300:Preoperative Care; D011673:Pulsatile Flow / Q000502:physiology; D020521:Stroke / Q000209:etiology; D017585:Ultrasonography, Doppler, Transcranial