Chen CJ, et al. – This systematic review aimed to examine the recent literature regarding endovascular mechanical thrombectomy (EMT) for acute M2 occlusions. For acute M2 occlusion, EMT afforded functional independence to the majority of patients, with a modest rate of symptomatic intracerebral hemorrhage (ICH). However, the benefit of M2 thrombectomy using stent retriever or direct aspiration techniques remained unclear compared to the natural history of distal middle cerebral artery (MCA) occlusions.

• For this study, the authors reviewed the literature to identify all studies of patients with acute M2 occlusions who underwent EMT which were published after January 1, 2015.
• They defined excellent and good outcomes as modified Rankin Scale of 0-1 and 0-2 at 3 months, respectively.
• They defined successful reperfusion as modified Thrombolysis In Cerebral Infarction (mTICI) score of 2b-3.

• The authors included 8 studies in the analysis, comprising 630 EMT-treated patients with acute M2 occlusions.
• In this study, the median National Institute of Health Stroke Scale score ranged from 10-16, and the median Alberta Stroke Program Computed Tomography Score ranged from 9-10.
• At 3-month follow-up, they observed excellent and good outcomes in 40% and 62% of acute M2 occlusion patients who underwent EMT, respectively, with a mortality rate of 11%.
• They achieved successful reperfusion in 78% of cases.
• As per the outcomes, post-procedural intracerebral hemorrhage (ICH) occurred in 14% of patients, including a symptomatic ICH rate of 5%.