Neuroprotective effects of hypothermia in acute ischemic stroke have been demonstrated in various animal experiments, but these results have not been convincingly confirmed in patients. Systemic hypothermia often leads to adverse effects that may offset the potential beneficial effects of hypothermia. Endovascular recanalization therapy by intra-arterial thrombolysis, stenting, or mechanical clot extraction has proven effective in patients with large proximal vessel occlusion. We have previously shown in animal studies that selective intra-arterial cold saline infusion is feasible during endovascular treatment. In this study, we evaluated the feasibility and safety of this technique in patients.