The Safety and Feasibility of Mechanical Thrombectomy for Mild Acute Ischemic Stroke With Large Vessel Occlusion

BACKGROUND: Prospective evidence to support mechanical thrombectomy (MT) for mild ischemic stroke with large vessel occlusion (LVO) is lacking. There is uncertainty about using an invasive procedure in patients with mild symptoms. OBJECTIVE: To evaluate the safety and feasibility of MT in patients with mild symptoms and LVO. METHODS: Our single-arm prospective pilot study recruited patients with LVO and initial National Institute of Health Stroke Scale (NIHSS) <6, who underwent standard MT. Primary safety endpoints were symptomatic intracerebral hemorrhage (sICH), and/or worsening NIHSS by ≥4 points. Secondary endpoints included angiographic recanalization, NIHSS change, final infarct volume, and modified Rankin score (mRS). RESULTS: We enrolled 20 patients (mean age 65.6 ± 12.3 yr; 45% females). Thrombolysis in Cerebral Ischemia 2B/3 thrombectomy was achieved in 95%. No patients suffered sICH. One patient (5%) had neurologic worsening within 24 h because of underlying intracranial stenosis. No other complications or safety concerns were identified. Median NIHSS was significantly better at discharge (0.5, P = .007) and at last follow-up (0, P < .001) than before treatment (3). Mean post vs preintervention infarct volumes were small without significant difference (1.2 ml, P = .434). Most patients (85%) were discharged directly home. Excellent clinical outcome (mRS 0-1) at last follow-up was seen in 95% of patients. CONCLUSION: This is one of the first specifically designed prospective studies showing that MT is safe and feasible in patients with low NIHSS and LVO. Chronic underlying vasculopathy may be a challenging dilemma. We observed excellent clinical and radiographic outcomes, but randomized controlled trials are needed to demonstrate the efficacy of MT in this unique cohort.