Endovascular Thrombectomy for Distal Medium Vessel Occlusions of the Middle Cerebral Artery: A Safe and Effective Procedure

Distal medium vessel occlusions (DMVOs) are increasingly recognized as a next target for endovascular thrombectomy (EVT). Our objective was to investigate safety and clinical outcomes of EVT for DMVO of the middle cerebral artery (MCA). We analyzed data of the Lille Reperfusion Registry from January 2017 to September 2020. Patients with a primary or secondary DMVO of the MCA seen on pretreatment angiogram were included. Only patients with a eTICI score 2b50–2b67 on initial angiogram were considered. Baseline characteristics, angiographic clinical, and safety outcomes were compared between patients treated with EVT or standard medical treatment (no-EVT). Of the 171 patients included, 96 received EVT (46.9% male, 68.7 ± 15.8 years) and 75 received standard medical treatment (44% male, 73.9 ± 13.1 years). EVT patients had a better improvement of the NIHSS score at discharge (adjusted mean difference: 3.71; 95% CI: 1.18–6.24). In the distal M2 occlusions subgroup, EVT was significantly associated with a higher rate of early neurologic improvement (adjusted OR: 3.62 95% CI: 1.31–10.03), NIHSS improvement at discharge (adjusted mean difference: 5.23; 95% CI: 2.18–8.29), and improved modified Rankin Scale score at 3 months (adjusted common OR for 1 point improvement: 3.06; 95% CI: 1.30 to 7.23). Symptomatic intracranial hemorrhage occurred in 3.1% in the EVT group and in 9.5% in the no-EVT group. EVT for DMVO of the MCA appears to be safe and may lead to improved clinical outcomes. This effect was especially pronounced in patients with distal M2 occlusions, warranting randomized trials to validate this result.