title: Evaluation of cerebrovascular reserve in patients undergoing carotid artery stenting and its usefulness in predicting significant hemodynamic changes during temporary carotid occlusion.
abstract: We investigated the usefulness of cerebrovascular reserve (CVR) testing to predict severe hemodynamic changes during proximally protected carotid artery stenting. Of 90 patients referred, 63 eligible underwent complete evaluation of the extent of carotid artery disease and transcranial Doppler ultrasound (TCD) assessment of CVR by means of a breath-holding test and ophthalmic artery flow pattern evaluation. Periprocedural TCD monitoring of the ipsilateral middle cerebral artery flow was performed in 24 patients undergoing proximally protected procedure (requiring induction of flow arrest within internal carotid artery). Abnormal CVR was significantly less common in patients with unilateral compared to bilateral carotid artery disease (26.3 % vs. 76.9 %, p=0.02), while ophthalmic artery flow reversal was rare in patients with unilateral carotid artery disease (2.5 % vs. 42.9 %, p<0.01). During the induction of carotid flow arrest, the average mean flow velocity drop following external carotid artery occlusion was low (3.5 %, p=0.67) compared to the induction of complete flow arrest (32.8 %, p<0.01). Six patients had a total mean flow velocity drop >50 %, including 2 patients with normal pre-procedural CVR. Our results suggest that TCD evaluation of CVR is not a reliable predictor of hemodynamic changes induced during proximally protected carotid artery stenting in patients with unilateral carotid artery disease.
authors.affiliation: Department of Cardiology, Motol University Hospital, Second Medical School, Charles University, Prague, Czech Republic. mildaspacek@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Spacek
authors.forename: C
authors.initials: C
authors.lastname: Stechovsky
authors.forename: M
authors.initials: M
authors.lastname: Horvath
authors.forename: P
authors.initials: P
authors.lastname: Hajek
authors.forename: P
authors.initials: P
authors.lastname: Zimolova
authors.forename: J
authors.initials: J
authors.lastname: Veselka
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000502:physiology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging / Q000502:physiology; D011237:Predictive Value of Tests; D015607:Stents; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods / Q000592:standards*