BACKGROUND There is growing evidence suggesting efficacy of endovascular therapy for M2 occlusions of the middle cerebral artery. More than one recanalization attempt is often required to achieve successful reperfusion in M2 occlusions, associated with general concerns about the safety of multiple maneuvers in these medium vessel occlusions. AIM The aim of this study was to investigate the association between the number of recanalization attempts and functional outcomes in M2 occlusions in comparison with large vessel occlusions (LVO). METHODS Retrospective multicenter cohort study of patients who underwent endovascular therapy for primary M2 occlusions. Patients were enrolled in the German Stroke Registry at 1 of 25 comprehensive stroke centers between 2015 and 2021. The study cohort was subdivided into patients with unsuccessful reperfusion (mTICI 0-2a) and successful reperfusion (mTICI 2b-3) at first, second, third, fourth, or ⩾fifth recanalization attempt. Primary outcome was 90-day functional independence defined as modified Rankin Scale score of 0-2. Safety outcome was the occurrence of symptomatic intracranial hemorrhage. Internal carotid artery or M1 occlusions were defined as LVO and served as comparison group. RESULTS A total of 1078 patients with M2 occlusion were included. Successful reperfusion was observed in 87.1% and 90-day functional independence in 51.9%. The rate of functional independence decreased gradually with increasing number of recanalization attempts (p < 0.001). In both M2 occlusions and LVO, successful reperfusion within three attempts was associated with greater odds of functional independence, while success at ⩾fourth attempt was not. Patients with ⩾4 attempts exhibited higher rates of symptomatic intracranial hemorrhage in M2 occlusions (6.5% vs 2.7%, p = 0.02) and LVO (7.2% vs 3.5%, p < 0.001). CONCLUSION This study suggests a clinical benefit of successful reperfusion within three recanalization attempts in endovascular therapy for M2 occlusions, which was similar in LVO. Our findings reduce concerns about the risk-benefit ratio of multiple attempts in M2 medium vessel occlusions. DATA ACCESS STATEMENT The data that support the findings of this study are available on reasonable request after approval of the German Stroke Registry (GSR) steering committee. CLINICAL TRIAL REGISTRATION INFORMATION ClinicalTrials.gov Identifier: NCT03356392.

中文翻译：

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M2 段大脑中动脉闭塞血管内治疗中再通尝试的预后价值。

背景越来越多的证据表明血管内治疗对大脑中动脉 M2 闭塞的疗效。在 M2 闭塞中，通常需要多次再通尝试才能实现成功的再灌注，这与人们普遍担心这些中等血管闭塞中多次操作的安全性有关。目的 本研究的目的是调查与大血管闭塞 (LVO) 相比，M2 闭塞的再通尝试次数与功能结果之间的关联。方法 对原发性 M2 闭塞接受血管内治疗的患者进行回顾性多中心队列研究。2015 年至 2021 年间，患者在 25 个综合性卒中中心之一的德国卒中登记中心入组。研究队列被细分为第一、第二次再灌注不成功 (mTICI 0-2a) 和再灌注成功 (mTICI 2b-3) 的患者。第三次、第四次或第五次再通尝试。主要结果是 90 天的功能独立性，定义为改良 Rankin 量表评分为 0-2。安全性结果是有症状的颅内出血的发生。颈内动脉或M1闭塞被定义为LVO并作为对照组。结果 共纳入 1078 例 M2 闭塞患者。87.1% 的患者成功再灌注，51.9% 的患者在 90 天后功能独立。随着再通尝试次数的增加，功能独立率逐渐下降 (p < 0.001)。在 M2 闭塞和 LVO 中，三次尝试内的成功再灌注与功能独立的更大几率相关，而第四次尝试的成功则不然。尝试 ⩾4 次的患者在 M2 闭塞（6.5% vs 2.7%，p = 0.02）和 LVO（7.2% vs 3.5%，p < 0.001）中表现出更高的症状性颅内出血发生率。结论 这项研究表明，在 M2 闭塞的血管内治疗中，三次再通尝试中成功再灌注具有临床益处，这在 LVO 中是相似的。我们的研究结果减少了对 M2 中型血管闭塞多次尝试的风险收益比的担忧。数据访问声明 在德国卒中登记处 (GSR) 指导委员会批准后，可根据合理请求提供支持本研究结果的数据。临床试验注册信息 ClinicalTrials.gov 标识符：NCT03356392。