Abstract 500: Selective Endovascular Brain Cooling Following Mechanical Thrombectomy in Acute Ischemic Stroke. Hybernia Medical First‐in‐Human Investigation.

Introduction/Purpose This is an ongoing First‐in‐Human single‐arm study, investigating the safety and feasibility of Hybernia Medical's Delta H Brain Cooling System in acute ischemic stroke patients. The Hybernia Medical Delta H System is intended to achieve targeted brain cooling for acute neuroprotection. Brain cooling is achieved via controlled and automated endovascular infusion of cold saline. ClinicalTrials.gov ID NCT06634303. Materials/Methods Acute ischemic stroke patients of ≤ 89y of age, baseline NIHSS ≥ 6, ASPECTS score 5‐10, within 24h of last‐known‐well, and arterial occlusion within the anterior cerebral circulation were included in the study. The minimum required modified treatment in cerebral infarction (mTICI) score post mechanical thrombectomy (MT) and before selective brain cooling was mTICI of 2a. Following MT, the Delta H Catheter was inserted into the ipsilateral internal carotid artery (ICA), and selective brain cooling was performed over 30 minutes. The controller‐programmed target temperature was a reduction by 4°C from baseline temperature. The procedure was concluded with a final cerebral angiogram. Clinical and imaging follow‐up periods included 24h‐48h, discharge, 30 days, and 90 days post intervention. Results The results from 4 patients are presented: age 68‐86y, 2 women, baseline NIHSS (11‐22), ASPECT score (5‐10), and time from ictus (1‐11 hours). Comorbidities included arterial hypertension (100%), diabetes mellitus (50%), dyslipidemia (100%), preceding open cardiac surgery in one patient, and antiplatelet or anticoagulant use (50%). Arterial occlusions were found in the left intracranial ICA, right MCA, left MCA, and left MCA complicated by left ACA embolism. Cerebral reperfusion of mTICI 2b or 2c was achieved post‐MT. Selective brain cooling was performed for 30 minutes in 3 patients and 17 minutes in 1 patient due to interruption by the Cooling System.There were no short‐term clinical adverse events associated with selective brain cooling, including intracerebral hemorrhage, vasospasm, or re‐occlusion. The process was well tolerated by the patients with no obvious symptoms or signs. Systemic hypothermia did not occur. Brain imaging did not reveal intracranial hemorrhage, ischemia expansion, or brain edema. 24‐48h NIHSS was 7‐16, and NIHSS at discharge ranged 1‐12. One patient died after hospital discharge and before the 30‐day evaluation from aspiration pneumonia which was deemed unrelated to the investigational procedure. Conclusion These early results from this ongoing First‐in‐Human investigation suggest brain cooling can be achieved safely and efficiently with the Hybernia Medical Delta H Brain Cooling System in acute ischemic stroke patients. The completion of this investigation with 90‐day clinical evaluation is pending. Additional clinical studies and trials are warranted to determine the efficacy of rapid and selective brain cooling and to investigate its neuroprotective capability in acute ischemia.