ABSTRACT NUMBER: ESOC2026A2418 SELECTIVE ENDOVASCULAR BRAIN COOLING FOLLOWING MECHANICAL THROMBECTOMY IN ACUTE ISCHEMIC STROKE: HYBERNIA MEDICAL FIRST-IN-HUMAN INVESTIGATION

Abstract Background and aims Despite advances in reperfusion therapies, many stroke patients remain with disability. Additional neuroprotective strategies are needed to reduce brain injury following ischemia and reperfusion. Hypothermia is considered the most effective adjunctive neuroprotective therapy; however, current cooling approaches are limited by slow onset, procedural complexity, and systemic adverse effects.Hybernia Medical has developed an endovascular intra-arterial brain cooling system that enables rapid and selective cerebral hypothermia through controlled, automated infusion of cold saline. This First-in-Human study evaluated the safety, feasibility, and technical performance of the Delta (Δ) H Brain Cooling System. Methods Single-arm study:anterior-circulation stroke patients received selective brain-cooling with ΔH-system immediately after EVT. Target hypothermia was a brain temperature reduction of 4°C for up to 30 minutes. Safety endpoints included intracranial imaging findings, neurological deterioration, and laboratory abnormalities. Clinical outcomes were assessed using NIHSS (24h and discharge), and modified Rankin Scale (mRS) at 30+90 days. Results Five patients underwent the cooling protocol. Mean infused saline volume was 885±330 mL. Target temperature was achieved within 37±15 seconds and maintained within ±1°C. Systemic temperature and hematocrit remained stable. One patient developed asymptomatic HI-2, considered part of natural post-reperfusion course. Early neurological improvement occurred in 4/5 patients. All patients were discharged. One patient died on day 27 from pneumonia unrelated to the procedure. At 90 days, 60% achieved mRS 0–2. Conclusions These results suggest that selective cerebral hypothermia with the ΔH system after mechanical thrombectomy is safe and feasible. Further studies are warranted, and a multicenter pilot trial is planned. Conflict of interest Marc Ribo: Nothing to disclose, Marc Rodrigo-Gispert: Nothing to disclose, Manuel Requena: Nothing to disclose, Marta de Dios: Nothing to disclose, Francesco Diana: Nothing to disclose, David Hernandez: Nothing to disclose, Alejandro Tomasello: Nothing to disclose, Marta Rubiera: Nothing to disclose, John Pile-Spellman: Hybernia, Jae H. Choi: Hybernia