Endovascular clot retrieval for M2 segment middle cerebral artery occlusion: a systematic review and meta‐analysis

INTRODUCTION: Endovascular clot retrieval (ECR) is the standard of care for acute ischaemic stroke (AIS) due to large vessel occlusion (LVO). However, isolated occlusion of the M2 segment of the Middle Cerebral Artery (MCA) was underrepresented in the landmark trials. Given the potential treatment benefit associated with M2 MCA occlusions, we aimed to evaluate the outcome of patients undergoing ECR for M2 occlusion. METHODS: We conducted a systematic review and meta-analysis of the available literature that included patients with M2 MCA occlusions who underwent ECR. Successful reperfusion was defined as a treatment in cerebral ischemia (TICI) score of 2b-3. Good outcome was defined as a modified Rankin Scale (mRS) score ≤ 2. We also analysed complications such as post-procedure symptomatic intracranial haemorrhage (sICH) and mortality at 3 months. RESULTS: 15 studies including 1105 patients with isolated M2 occlusions were analysed. Successful reperfusion occurred in in 75.4% (95% CI 67.7-84.1%) of patients; good outcome was observed in 58.3% (95% CI 51.7-63.8% of patients. The rate of sICH was 5.1% (95% CI 4.2-8.3%), and 3-month mortality rate was 12.2% (95% CI 10.4-16.3%). CONCLUSION: The outcomes of ECR treatment of M2 occlusions are favourable, with good safety profile. Comparison to medical management from large registries or randomized controlled trials is warranted. This article is protected by copyright. All rights reserved.