title: Intracranial Collateral Flow Estimated by Color Velocity Imaging Quantification Ultrasound: A Protector of Recurrent Stroke in Patient with Carotid Stenosis?
abstract: Stroke patients with carotid disease have a high risk of recurrence of disease. By measuring cerebral blood flow volume (BFV) using extracranial duplex technique for clinical estimation of intracranial collaterals, we aimed to investigate the relationship between the presence of intracranial collaterals and stroke recurrence in stroke patients with carotid disease. Consecutive stroke patients indicated for carotid duplex ultrasound investigations in our hospital were recruited during three years' period. Carotid stenosis was diagnosed as ≥50% stenosis and extracranial arterial BFV was measured by using color velocity imaging quantification ultrasound (CVIQ) software. Presence of intracranial collateral flow was defined as a blood flow volume of either ≥370 mL/min in common carotid artery or ≥120 mL/min in vertebral artery. Univariate and multivariate analyses were performed to determine the independent predictors of recurrent stroke. One hundred and twelve stroke patients (19.1%) with ≤50% carotid stenosis were recruited from consecutive ischemic stroke patients. During a mean follow-up of 28.6±13.1 months, recurrent stroke was recorded in 32 (28.6%) out of the total recruited patients. Estimated by blood flow volume measured by CVIQ, the patients with intracranial collateral flow had a lower rate of recurrent stroke than those without (9.5% vs. 33%, P=0.032). After adjusting for potential confounders, the presence of CVIQ-estimated intracranial collateral flow was an independent protector of recurrent stroke (OR, 0.169; 95% CI, 0.034- 0.842; P=0.03). It could be concluded that blood supply through intracranial collateral flow estimated by CVIQ technique may protect stroke patients with carotid stenosis from suffering recurrent stroke.
authors.forename: Hui
authors.initials: H
authors.lastname: Fang
authors.affiliation: Department of Medicine and Therapeutics, Faculty of Medicine, Prince of Wales Hospital, Shatin, Hong Kong. fiona.xy2000@gmail.com.
authors.forename: Xiang Yan
authors.initials: XY
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.forename: Bo
authors.initials: B
authors.lastname: Cheng
authors.forename: Yu Ming
authors.initials: YM
authors.lastname: Xu
authors.forename: Ka Sing
authors.initials: KS
authors.lastname: Wong
authors.affiliation: Department of Imaging and Interventional Radiology, Faculty of Medicine, Prince of Wales Hospital, Shatin, Hong Kong. stellaho@cuhk.edu.hk.
authors.forename: Stella Sin
authors.initials: SS
authors.lastname: Ho
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D014463:Ultrasonography / Q000379:methods