Endovascular Therapy for Acute Ischemic Stroke With Occlusion of the Middle Cerebral Artery M2 Segment

Abstract

IMPORTANCE Randomized clinical trials have shown the superiority of endovascular therapy (EVT) compared with best medical management for acute ischemic strokes with large vessel occlusion (LVO) in the anterior circulation. However, of 1287 patients enrolled in 5 trials, 94 with isolated second (M2) segment occlusions were randomized and 51 of these received EVT, thereby limiting evidence for treating isolated M2 segment occlusions as reflected in American Heart Association guidelines. OBJECTIVE To evaluate EVT safety and effectiveness in M2 occlusions in a cohort of patients with acute ischemic stroke. DESIGN, SETTING, AND PARTICIPANTS This multicenter retrospective cohort study pooled patients with acute ischemic strokes and LVO isolated to M2 segments from 10 US centers. Patients with acute ischemic strokes and LVO in M2 segments presenting within 8 hours from their last known normal clinical status (LKN) from January 1, 2012, to April 30, 2015, were divided based on their treatment into EVT and medical management groups. Logistic regression was used to compare the 2 groups. Univariate and multivariate analyses evaluated associations with good outcome in the EVT group. MAIN OUTCOMES AND MEASURES The primary outcome was the 90-day modified Rankin Scale score (range, 0-6; scores of 0-2 indicate a good outcome); the secondary outcome was symptomatic intracerebral hemorrhage. RESULTS A total of 522 patients (256 men [49%]; 266 women [51%]; mean [SD] age, 68 [14.3] years) were identified, of whom 288 received EVT and 234 received best medical management. Patients in the medical management group were older (median [interquartile range] age, 73 [60-81] vs 68 [56-78] years) and had higher rates of intravenous tissue plasminogen activator treatment (174 [74.4%] vs 172 [59.7%]); otherwise the 2 groups were balanced. The rate of good outcomes was higher for EVT (181 [62.8%]) than for medical management (83 [35.4%]). The EVT group had 3 times the odds of a good outcome as the medical management group (odds ratio [OR], 3.1; 95% CI, 2.1-4.4; P < .001) even after adjustment for age, National Institute of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomographic Score (ASPECTS), intravenous tissue plasminogen activator treatment, and time from LKN to arrival in the emergency department (OR, 3.2; 95% CI, 2-5.2; P < .001). No statistical difference in symptomatic intracerebral hemorrhage was found (5.6% vs 2.1% for the EVT group vs the medical management group; P = .10). The treatment effect did not change after adjusting for center (OR, 3.3; 95% CI, 1.9-5.8; P < .001). Age, NIHSS score, ASPECTS, time from LKN to reperfusion, and successful reperfusion score of at least 2b (range, 0 [no perfusion] to 3 [full perfusion with filling of all distal branches]) were independently associated with good outcome of EVT. A linear association was found between good outcome and time from LKN to reperfusion. CONCLUSIONS AND RELEVANCE Although a randomized clinical trial is needed to confirm these findings, available...

A Comparison of Mechanical Thrombectomy in the M1 and M2 Segments of the Middle Cerebral Artery: A Review of 585 Consecutive Patients

“…However, according to the data of Dorn et al [9], Coutinho et al [10] and Sarraj et al [8] as well as our own data, this does not appear to be the case. Furthermore, the idea that the more distal location of the occlusion and the potentially smaller brain volume affected should deter physicians from pursuing mechanical recanalization is also disputable, since in the study of Sheth et al [11] one-third of patients with M2 occlusions had infarct volumes of ≥50 mL and 11% had infarct volumes of ≥90 mL [11].…”

“…Despite these challenges, there is evidence that the M2 branches are amenable to thrombectomy and that good results can be obtained. Sarraj et al [8] recently published their results from a retrospective cohort study of pooled patients with acute ischaemic strokes with involvement of isolated M2 vessels from 10 US centres. This study identified 522 patients, of whom 288 underwent mechanical thrombectomy and 234 received best medical management.…”

Mechanical Thrombectomy for M2 Occlusions: A Single-Centre Experience

“…These results support the use of mechanical thrombectomy in patients presenting with M2 occlusion despite the inherent limitations of a retrospective study. Our results are very similar to those of Sarraj et al [21] and Coutinho et al [19] with 54.6% of the patients in our study showing an mRS score ≤2 at 90 days. Similarly, an mRS score ≥5 was seen in 20.8% of the patients in our cohort and in 19.8% of the patients in that of Sarraj et al [21].…”

“…Our results are very similar to those of Sarraj et al [21] and Coutinho et al [19] with 54.6% of the patients in our study showing an mRS score ≤2 at 90 days. Similarly, an mRS score ≥5 was seen in 20.8% of the patients in our cohort and in 19.8% of the patients in that of Sarraj et al [21]. Death occurred in 12% of the Coutinho et al [19 ]cohort and in 14.2% of our cohort, which is again remarkably similar.…”

“…Sarraj et al [21] recently performed a multi-centre retrospective cohort study with patients pooled from 10 centres in the US. The aim of this study was to determine the safety and effectiveness of mechanical thrombectomy of M2 occlusions as compared to the best medical therapy.…”