Endovascular treatment achieves better outcomes than best medical management in patients with M2 occlusion and high stroke severity: a meta-analysis

Background The lack of randomized evidence makes it difficult to establish reliable treatment recommendations for patients with M2 occlusion. This study aims to compare the efficacy and safety of endovascular treatment (EVT) with best medical management (BMM) in patients with M2 occlusion, and to investigate whether the optimal treatment varies according to stroke severity. Methods Comprehensive literature retrieval was conducted to identify studies that directly compared the outcomes of EVT and BMM. According to stroke severity, the study population were classified into those with moderate-severe stroke and those with mild stroke. National Institute of Health Stroke Scale (NIHSS) scores ≥ 6 was defined as moderate-severe stroke, and NIHSS scores 0–5 as mild stroke. Random-effects meta-analyses were performed to measure the symptomatic intracranial hemorrhage (sICH) within 72 h, and the modified Rankin Scale (mRS) scores 0–2 and the mortality at 90 days. Results Totally, 20 studies were identified, including 4358 patients. In the moderate-severe stroke population, the EVT had 82% higher odds for mRS scores 0–2 (OR 1.82, 95% CI 1.34–2.49) and a 43% lower odds for mortality (OR 0.57, 95% CI 0.39–0.82) compared with the BMM. However, no difference was found in the sICH rate (OR 0.88, 95% CI 0.44–1.77). In the mild stroke population, no differences were observed in the mRS scores 0–2 (OR 0.81, 95% CI 0.59–1.10) or mortality (OR 1.23, 95% CI 0.72–2.10) between EVT and BMM, whereas EVT was associated with higher sICH rate (OR 4.21, 95% CI 1.86–9.49). Conclusion EVT may be only beneficial for patients with M2 occlusion and high stroke severity, but not for those with NIHSS scores 0–5.