Objective: To analyze the influence of collateral circulation on long-term prognosis in strokep atients with severe stenosis and occlusion of M1 segment of middle cerebral artery (MCA) that failed to achieve early reperfusion (ER).

Methods: From September 2017 to August 2019, we recruited 71 patients with severe stenosis and occlusion on M1 segment of MCA diagnosed by CT angiography (CTA) or CT perfusion imaging (CTP) who failed to achieve ER were enrolled. They were divided into good collateral circulation group (42 cases) and poor collateral circulation group(29 cases) and the logistic regression analysis was used for statistical analysis.

Results: The National Institutes of Health Stroke Scale (NIHSS) score and the modifed Ranking Scale(mRS) score at 3 months and 6 months after the onset in the good collateral circulation group were all lower than those in the poor collateral circulation group(P<0.05)The multivariate analysis showed that the excellent functional outcome (0≤mRS score≤1;odds ratio:4.84,95% confidence interval: 1.28-18.22), good functional outcome(0≤mRS score<2; odds ratio: 5.18,95% confidence interval: 1.38-19.35)at 3 months and excellent functional outcome at 6 months(odds ratio: 8.75, 95% confidence interval: 2.37-32.66) in the good collateral circulation group were higher than those in the poor collateral circulation group(P<0.05). The risk of stroke recurrence in patients with good collateral circulation (odds ratio: 0.10,95% confidence interval: 0.01-0.69) was lower than that in patients with poor collateral circulation(P<0.05).

Conclusion: Good collateral circulation can improve the long-term excellent functional outcome and reduce the risk of stroke recurrence in patients with severe stenosis and occlusion of MCA who fail to achieve ER.