Abstract DP195: Thrombectomy For Anterior Versus Posterior Middle Cerebral Artery Branch Occlusion In The Endovascular Treatment of Stroke Due to Medium-Vessel Occlusion Trial

Introduction: The Endovascular Treatment of Stroke Due to Medium-Vessel Occlusion (ESCAPE-MeVO) trial did not show superiority of thrombectomy over medical management for patients with an acute ischemic stroke secondary to a medium-vessel occlusion (MeVO). The majority of patients included in this trial had an occlusion of the M2/M3 segment of the middle cerebral artery (MCA). The two main branches of the MCA differ in their anatomy and diameter: while the anterior M2/M3 branch is typically of smaller caliber and tortuous, the posterior M2/M3 branch is typically of larger caliber and more straight, making endovascular thrombectomy maneuvers easier and safer. We aimed to assess if the type of branch occlusion (anterior versus posterior branch of the MCA) had any effect on the outcomes after thrombectomy, and if there was treatment effect modification of EVT by the location of the MCA branch occlusion. Methods: This was a sub-group analysis of the ESCAPE-MeVO trial: patients harboring an MCA occlusion were classified into two groups: anterior-MCA-MeVO (occlusion of the anterior branch) and posterior-MCA-MeVO (occlusion of the posterior branch). Outcomes a) between thrombectomy patients with anterior vs. posterior MCA occlusions and b) thrombectomy and best medical care arm patients stratified by occlusion location were compared using descriptive statistics and logistic regression with adjustment for key co-variates. Thrombectomy effect modification by occlusion location was assessed with multiplicative interaction terms. Results: A total of 442 patients were therefore included in the study (170 anterior-MCA-MeVOs and 272 posterior-MCA-MeVOs). Baseline characteristics were similar between groups. Outcomes of patients with anterior-MCA-MeVO occlusion and posterior-MCA-MeVO occlusion treated with thrombectomy were similar, both in terms of angiographic outcomes and clinical outcomes at 3 months follow-up ( Figure 1 ). Finally, there was no significant difference between thrombectomy and standard medical care for patients in the anterior-MCA-MeVO group or patients in the posterior-MCA-MeVO group ( Figure 2 ), and no evidence of EVT effect modification by MCA occlusion location on 90-day mRS or any other outcome was seen. Conclusion: There was no significant association of MCA-MeVO occlusion location (anterior versus posterior) and post-thrombectomy outcomes and no EVT effect modification by occlusion location was seen in the ESCAPE-MeVO trial.