Improving the Evaluation of Collateral Circulation by Multiphase Computed Tomography Angiography in Acute Stroke Patients Treated with Endovascular Reperfusion Therapies

Alvaro García-Tornel; Vanessa Carvalho; Sandra Boned; Alan Flores; David Rodríguez-Luna; Jorge Pagola; Marian Muchada; Estela Sanjuan; Pilar Coscojuela; Jesus Juega; Noelia Rodriguez-Villatoro; Bijoy Menon; Mayank Goyal; Marc Ribó; Alejandro Tomasello; Carlos A Molina; Marta Rubiera

doi:10.1159/000448525

Improving the Evaluation of Collateral Circulation by Multiphase Computed Tomography Angiography in Acute Stroke Patients Treated with Endovascular Reperfusion Therapies

Interv Neurol. 2016 Sep;5(3-4):209-217. doi: 10.1159/000448525. Epub 2016 Sep 1.

Authors

Alvaro García-Tornel¹, Vanessa Carvalho², Sandra Boned¹, Alan Flores³, David Rodríguez-Luna¹, Jorge Pagola¹, Marian Muchada¹, Estela Sanjuan¹, Pilar Coscojuela⁴, Jesus Juega¹, Noelia Rodriguez-Villatoro¹, Bijoy Menon⁵, Mayank Goyal⁵, Marc Ribó¹, Alejandro Tomasello⁴, Carlos A Molina¹, Marta Rubiera¹

Affiliations

¹ Stroke Unit, Neurology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
² Internal Medicine, Hospital Luz, Lisboa, Portugal, Alta., Canada.
³ Neurology Department, Hospital de Clínicas U.N.A. Instituto Randall, Asunción, Paraguay, Alta., Canada.
⁴ Interventional Neuroradiology Unit, Radiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain, Alta., Canada.
⁵ Interventional Neuroradiology, Radiology Department, University of Calgary, Calgary, Alta., Canada.

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 cm³ on sCTA, p = 0.04; 17.2 vs. 97.8 cm³ on 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.

Conclusion: 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.

Keywords: Acute stroke; Collateral circulation; Computed tomography angiography; Multiphase computed tomography angiography.