Intraoperative Hypothermia for Aneurysm Surgery Trial, Part 2 "IHAST2"


Phase N/A Results

Trial Description

To investigate the neuroprotective efficacy of mild intraoperative hypothermia (target core temperature 33°C) during open craniotomies performed to clip intracranial aneurysms.


  • Hypothermia Device
    Intervention Desc: Reduction of brain temperature and body temperature for neuroprotection

Trial Design

Prospective, randomized, controlled, multicenter trial blinded with respect to surgeons, patients, and physicians performing outcome assessments, but not with respect to anesthesiologists.

Patient Involvement

Patients will be randomized into either a normothermic group (target surgical temperature 36.5°C) or a hypothermic group (target surgical temperature 33°C). Hypothermic patients will be surface-cooled during the procedure, and warmed immediately after the aneurysm clip is placed. All patients will receive a standardized anesthetic, and their surgeries will be performed according to local standards. They will receive clinical and neurological follow-up monitoring during their hospital stays or until 14 days after their surgeries, whichever is shorter. They will then have phone or clinical contacts at 3, 6, and 9 weeks postoperatively, and will undergo a full neurological evaluation at 3 months.


Type Measure Time Frame Safety Issue
Primary Glasgow Outcome Score (GOS) at 3 months after surgery.
Secondary In-hospital secondary outcomes include duration of intubation and ventilation, duration of critical care, length of hospitalization, and discharge destination. 3-month postoperative secondary outcomes include NIH Stroke Scale scores, Barthel Indices, Rankin Disability scores, a 5-test neuropsychology battery, and the cognitive performance on the Mini-Mental State Examination.


National Institute for Neurological Disorders and Stroke, NIH