Importance The benefit of mechanical thrombectomy (MT) in patients with stroke presenting with mild deficits (National Institutes of Health Stroke Scale [NIHSS] score <6) owing to emergency large-vessel occlusion (ELVO) remains uncertain.

Objective To assess the outcomes of patients with mild-deficits ELVO (mELVO) treated with MT vs best medical management (bMM).

Data Sources We retrospectively pooled patients with mELVO during a 5-year period from 16 centers. A meta-analysis of studies reporting efficacy and safety outcomes with MT or bMM among patients with mELVO was also conducted. Data were analyzed between 2013 and 2017.

Study Selection We identified studies that enrolled patients with stroke (within 24 hours of symptom onset) with mELVO treated with MT or bMM.

Main Outcomes and Measures Efficacy outcomes included 3-month favorable functional outcome and 3-month functional independence that were defined as modified Rankin Scale scores of 0 to 1 and 0 to 2, respectively. Safety outcomes included 3-month mortality and symptomatic and asymptomatic intracranial hemorrhage (ICH).

Results We evaluated a total of 251 patients with mELVO who were treated with MT (n = 138; 65 women; mean age, 65.2 years; median NIHSS score, 4; interquartile range [IQR], 3-5) or bMM (n = 113; 51 women; mean age, 64.8; median NIHSS score, 3; interquartile range [IQR], 2-4). The rate of asymptomatic ICH was lower in bMM (4.6% vs 17.5%; P = .002), while the rate of 3-month FI (after imputation of missing follow-up evaluations) was lower in MT (77.4% vs 88.5%; P = .02). The 2 groups did not differ in any other efficacy or safety outcomes. In multivariable analyses, MT was associated with higher odds of asymptomatic ICH (odds ratio [OR], 11.07; 95% CI, 1.31-93.53; P = .03). In the meta-analysis of 4 studies (843 patients), MT was associated with higher odds of symptomatic ICH in unadjusted analyses (OR, 5.52; 95% CI, 1.91-15.49; P = .002; I² = 0%). This association did not retain its significance in adjusted analyses including 2 studies (OR, 2.06; 95% CI, 0.49-8.63; P = .32; I² = 0%). The meta-analysis did not document any other independent associations between treatment groups and safety or efficacy outcomes.

Conclusions and Relevance Our multicenter study coupled with the meta-analysis suggests similar outcomes of MT and bMM in patients with stroke with mELVO, but no conclusions about treatment effect can be made. The clinical equipoise can further be resolved by a randomized clinical trial.

重要性 由于紧急大血管闭塞（ELVO）而出现轻度缺陷（美国国立卫生研究院卒中量表[NIHSS]评分<6）的卒中患者，机械血栓切除术（MT）的获益仍不确定。

目的 评估接受MT和最佳药物治疗（bMM）治疗的轻度ELVO（mELVO）患者的预后。

数据来源 我们回顾性收集了16个中心在5年内的mELVO患者。还进行了荟萃分析，对mELVO患者中MT或bMM的疗效和安全性结果进行报告。分析了2013年至2017年之间的数据。

研究选择 我们确定了一些研究，这些研究招募了接受MT或bMM治疗的mELVO中风（症状发作后24小时内）的患者。

主要结果和措施 疗效结果包括3个月的有利功能结局和3个月的功能独立性，分别定义为改良的Rankin量表评分为0：1和0：2。安全结果包括3个月的死亡率以及有症状和无症状的颅内出血（ICH）。

结果 我们评估了251例接受MT治疗的mELVO患者（n = 138； 65名女性；平均年龄：65.2岁； NIHSS评分中位数：4；四分位间距[IQR]：3-5）或bMM（n = 113名女性； 113名女性；平均年龄64.8； NIHSS中位数3；四分位间距[IQR] 2-4）。MT患者的无症状性ICH发生率较低（4.6％vs. 17.5％；P  = .002），而MT的3个月FI发生率（77.4％vs 88.5％）较低（归因于随访评估缺失） ；P  = .02）。两组在其他疗效或安全性方面均无差异。在多变量分析中，MT与无症状性ICH的可能性更高相关（赔率[OR]为11.07； 95％CI为1.31-93.53；P = .03）。在对4项研究（843例患者）的荟萃分析中，MT在未经调整的分析中与症状性ICH发生率较高相关（OR为5.52； 95％CI为1.91-15.49；P  = 0.002；I ²  = 0％）。这种关联在包括2项研究的校正分析中未保留其意义（OR，2.06； 95％CI，0.49-8.63；P  = 0.32；I ²  = 0％）。荟萃分析未记录治疗组与安全性或功效结果之间的任何其他独立关联。

结论与相关性 我们的多中心研究加上荟萃分析表明，mELVO脑卒中患者MT和bMM的结局相似，但尚无治疗效果的结论。临床平衡可以通过随机临床试验进一步解决。