To investigate the effectiveness of digital subtraction angiography (DSA) in predicting the clinical outcome of acute ischemic stroke patients who received mechanical reperfusion therapy due to large artery occlusion (LAO) in anterior circulation.

Collaterals of individuals were evaluated according to American Society of Interventional and Therapeutic Neuroradiology collateral grading system (ACG) based on DSA sequences acquired before any intra-arterial intervention. The relationship between baseline information and clinical outcome of patients with different ACG scores was retrospectively analyzed.

Thirty-three cases were valid for analysis, with 12 having limited collaterals (ACG=0/1), 13 having moderate ones (ACG=2) and 8 abundant (ACG=3/4). The rate of independent living (mRS scores 0-2) in 3 groups at 3 months was 0/12, 6/13, 8/8 respectively, which increased with better collaterals (χ²=21.662, P<0.01; r=0.770, P<0.01). The rates of intracranial hemorrhage (6/12, 7/13, 1/8; χ²=7.337, P=0.027) and mortality (6/12, 1/13, 0/8; χ²=8.017, P=0.009) showed statistically significant difference among 3 groups. The rates of independent living of reperfused patients (achieving modified Treatment In Cerebral Ischemia scale (mTICI) 2b or 3) in 3 groups were 0/8, 6/11 and 8/8 (χ²=17.196, P<0.01; r=0.770, P<0.01), respectively.

DSA-based ACG is a simple and effective tool in predicting clinical outcomes in patients with LAO in anterior circulation after mechanical reperfusion therapy, and low ACG grades indicate poor outcome despite reperfusion.

Acute ischemic stroke; Collaterals; Mechanical reperfusion; Digital subtraction angiography