title: Improving the Evaluation of Collateral Circulation by Multiphase Computed Tomography Angiography in Acute Stroke Patients Treated with Endovascular Reperfusion Therapies.
abstract: Good collateral circulation (CC) is associated with favorable outcomes in acute stroke, but the best technique to evaluate collaterals is controversial. Single-phase computed tomography angiography (sCTA) is widely used but lacks temporal resolution. We aim to compare CC evaluation by sCTA and multiphase CTA (mCTA) as predictors of outcome in endovascular treated patients.
  
  
  METHODS
  Consecutive endovascular treated patients with M1 middle cerebral artery (MCA) or terminal intracranial carotid artery (TICA) occlusion confirmed by sCTA were included. Two more CTA acquisitions with 8- and 16-second delays were performed for mCTA. Endovascular thrombectomy was performed independently of the CC status according to a local protocol [Alberta Stroke Program Early CT score (ASPECTS) >6, modified Rankin scale (mRS) score <3]. CC on sCTA and mCTA were compared.
  
  
  RESULTS
  108 patients were included. Their mean age was 69.6 ± 13 years and their median National Institutes of Health Stroke Scale (NIHSS) score was 17 (interquartile range 8). 79 (73.1%) had M1 MCA and 29 (26.9%) TICA occlusions. The mean time from symptom onset to CTA was 146.8 ± 96.5 min. On sCTA, 50.9% patients presented good CC vs. 57.5% on mCTA. Good CC status in both sCTA and mCTA had a lower 24-hour infarct volume (27.4 vs. 74.8 cm3on sCTA, p = 0.04; 17.2 vs. 97.8 cm3on mCTA, p < 0.01). However, only good CC on mCTA was associated with lower 24-hour (5 vs. 8.5, p = 0.04) and median discharge NIHSS (2 vs. 4.5, p = 0.04) scores and functional independency (mRS score <3) at 3 months (76.9 vs. 23.1%, p < 0.01). In a logistic regression model including age, NIHSS, ASPECTS and recanalization, only age (OR 0.96, 95% CI 0.93-0.99, p = 0.02) and good CC on mCTA (OR 5, 95% CI 1.99-12.6, p < 0.01) were independent predictors of functional outcome at 3 months.
  
  
  CONCLUSIONS
  CC evaluation by mCTA is a better prognostic marker than CC evaluation by sCTA for clinical and functional endpoints in acute stroke patients treated with endovascular thrombectomy.
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Alvaro
authors: A
authors: García-Tornel
authors: Internal Medicine, Hospital Luz, Lisboa, Portugal, Alta., Canada.
authors: Vanessa
authors: V
authors: Carvalho
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Sandra
authors: S
authors: Boned
authors: Neurology Department, Hospital de Clínicas U.N.A. Instituto Randall, Asunción, Paraguay, Alta., Canada.
authors: Alan
authors: A
authors: Flores
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: David
authors: D
authors: Rodríguez-Luna
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Jorge
authors: J
authors: Pagola
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Marian
authors: M
authors: Muchada
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Estela
authors: E
authors: Sanjuan
authors: Interventional Neuroradiology Unit, Radiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Pilar
authors: P
authors: Coscojuela
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Jesus
authors: J
authors: Juega
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Noelia
authors: N
authors: Rodriguez-Villatoro
authors: Interventional Neuroradiology, Radiology Department, University of Calgary, Calgary, Alta., Canada.
authors: Bijoy
authors: B
authors: Menon
authors: Interventional Neuroradiology, Radiology Department, University of Calgary, Calgary, Alta., Canada.
authors: Mayank
authors: M
authors: Goyal
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Marc
authors: M
authors: Ribó
authors: Interventional Neuroradiology Unit, Radiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Alejandro
authors: A
authors: Tomasello
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Carlos A
authors: CA
authors: Molina
authors: Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
authors: Marta
authors: M
authors: Rubiera
keywords: Acute stroke; Collateral circulation; Computed tomography angiography; Multiphase computed tomography angiography