Transoral ultrasonographic evaluation of carotid flow in predicting cerebral hemodynamics after carotid endarterectomy.
OBJECTIVE
We investigated whether measurement of blood flow in the extracranial distal internal carotid artery (ICA) by transoral carotid ultrasonography (TOCU) can predict the cerebral hemodynamics and the hemodynamic effect of carotid endarterectomy (CEA) in patients with unilateral carotid stenosis.


METHODS
Forty-nine patients with unilateral ICA stenosis who underwent CEA were studied. Preoperative blood flow in the poststenotic portion of the extracranial ICA was studied by using TOCU. Regional cerebral blood flow (rCBF) and vasoreactivity to acetazolamide (VR) in the territory of the middle cerebral artery were investigated by using single-photon emission CT (SPECT) before, 2 weeks after, and 3 months after CEA.


RESULTS
Doppler flow velocities in the extracranial distal ICA measured transorally by TOCU correlated with baseline as well as postacetazolamide rCBF in the ipsilateral side (regression analysis, P < .05). Diameter and blood flow volume in the extracranial distal ICA were associated with ipsilateral postacetazolamide rCBF and VR (regression analysis, P < .05). When the patients were divided into 2 groups according to the ICA volume flow distal to a carotid stenosis, group I < 3.5 mL/s and group II > 3.5 mL/s, ipsilateral postacetazolamide rCBF in group I was significantly lower than that in group II (P = .008). Ipsilateral postacetazolamide rCBF (analysis of variance [ANOVA], P = .02) and VR (ANOVA, P = .03) significantly improved after CEA for 3 months in group I but not in group II.


CONCLUSIONS
TOCU can detect the decrease in poststenotic flow of the distal extracranial ICA that is indicative of impaired intracranial hemodynamics and predictive for improvement of cerebral blood flow after CEA in patients with unilateral carotid stenosis.
Kamouchi
M
M
Department of Cerebrovascular Disease, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan.
Kishikawa
K
K
Okada
Y
Y
Inoue
T
T
Toyoda
K
K
Ibayashi
S
S
Iida
M
M
D000086:Acetazolamide / Q000494:pharmacology; D000368:Aged; D001783:Blood Flow Velocity; D001810:Blood Volume; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D002560:Cerebrovascular Circulation; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
D000086:Acetazolamide