Benefit of endovascular thrombectomy for M2 middle cerebral artery occlusion in the ARISE II study

Abstract

BackgroundThe benefit of endovascular thrombectomy for acute ischemic stroke with M2 segment middle cerebral artery occlusion remains controversial, with uncertainty and paucity of data specific to this population.ObjectiveTo compare outcomes between M1 and M2 occlusions in the Analysis of Revascularization in Ischemic Stroke with EmboTrap (ARISE II) trial.MethodsWe performed a prespecified analysis of the ARISE II trial with the primary outcome of 90-day modified Rankin Scale score of 0–2, which we termed good outcome. Secondary outcomes included reperfusion rates and major adverse events. The primary predictor was M2 occlusion, which we compared with M1 occlusion.ResultsWe included 183 patients, of whom 126 (69%) had M1 occlusion and 57 (31%) had M2 occlusion. There was no difference in the reperfusion rates or adverse events between M2 and M1 occlusions. The rate of good outcome was not different in M2 versus M1 occlusions (70.2% vs 69.7%, p=0.946). In a logistic regression model adjusted for age, sex, and baseline National Institutes of Health Stroke Scale score, M2 occlusions did not have a significantly different odds of good outcome compared with M1 occlusions (OR 0.94, 95% CI 0.47 to 1.88, p=0.87).ConclusionIn ARISE II, M2 occlusions achieved a 70.2% rate of good outcome at 90 days, which is above published rates for untreated M2 occlusions and superior to prior reports of M2 occlusions treated with endovascular thrombectomy. We also report similar rates of good outcome, successful reperfusion, death, and other adverse events when comparing the M1 and M2 occlusions.

Endovascular reperfusion of M2 occlusions in acute ischemic stroke reduced disability and mortality: ETIS Registry results

“…Our study adds to the growing literature supporting the efficacy of EVT in M2 occlusions,1–10 as well as its cost-effectiveness 14. Li et al performed a meta-analysis of studies evaluating the clinical and safety outcomes of EVT for M2 occlusions 8.…”

“…The best treatment strategy for M2 occlusion is uncertain due to the lack of randomized trials focusing on this subgroup of patients with M2 occlusion. However, several studies have reported the efficacy and safety of endovascular treatment (EVT) in M2 occlusions with conflicting results 1–10. Moreover, a HERMES meta-analysis suggested a potential benefit from EVT compared with medical therapy in M2 occlusions, although it was limited by small sample size 1.…”

3D Turbo Spin-echo MRI-based Mechanical Thrombectomy at Middle Cerebral Artery Bifurcations

“… 3) Although mechanical thrombectomy for M2 occlusions can improve stroke outcomes, randomized clinical trials have not established the efficacy compared with medical treatment. 1 , 4 , 7 , 8) Sarraj et al showed a recanalization rate of 78%, an incidence of symptomatic intracerebral hemorrhage of 5.6%, and functional independence of 62.8% in a cohort of patients with acute M2 occlusion. 7) However, the reported rate of good outcome with medical treatment is as high as 54.2%.…”

“…3) Although mechanical thrombectomy for M2 occlusions can improve stroke outcomes, randomized clinical trials have not established the efficacy compared with medical treatment. 1,4,7,8)…”

“… 1 , 2) The therapeutic applications for the distal cerebral artery, such as the middle cerebral artery (MCA) segment 2 (M2), have been expanded with development of neurovascular devices. 3 , 4) However, the stent retrieval procedure for small or inflectional branches may injure the vascular endothelium, leading to dissection or vessel perforation. 5) In particular, as for arterial occlusion at MCA bifurcations, blind catheterization through the thrombus to the M2 is required and there is a high risk of straightening or perforator avulsion during stent retrieval.…”