Despite the recent technical evolution of the endovascular treatment of acute ischemic stroke, late and incomplete recanalization can be achieved after several maneuvers but with a potentially higher risk of futile reperfusion and complications, such as clot fragmentation. The aim of this article is to investigate the impact of the angiographic phenotype of M1-middle cerebral artery occlusions, classified as regular and irregular in aspect, on the results of treatment by stent retrievers (SRs) or contact aspiration (CA). From January to April 2016, 84 consecutive patients, admitted for acute ischemic stroke with a middle cerebral artery occlusion, were treated by endovascular therapy. Among them, 60 patients (26M, 34F, median age, 70.5; interquartile range, 58.5-80.0) were treated by SR (25/60, 41.7%) or CA (35/60, 58.3%) as a first-line approach in 2 experienced centers. Patients' characteristics, timing, and procedural data were prospectively recorded and compared between the 2 study subgroups (regular and irregular phenotype). A regular phenotype at the occlusion site was observed in 24 patients (40%). Among these, successful recanalization after the first-line strategy (Thrombolysis in Cerebral Infarction 2b-3) was achieved in 100% of patients treated by CA and in only 33.3% of patients treated by SR (PPP The angiographic phenotype of the occlusion site may be associated with a different response to SR and CA in this preliminary experience.