Abstract TP14: Simultaneous Endovenous Hypothermia and Intra-Arterial Thrombectomy for Acute Ischemic Stroke is Safe, Feasible and Does Not Require General Anesthesia

Background: Hypothermia is a promising neuroprotectant. Amelioration of reperfusion injury after recanalization is a potential benefit. Due to easy access to the femoral vein, endovenous hypothermia can be combined with intra-arterial therapy. Hypothermia and shivering control is possible without mechanical ventilation, deep sedation or paralytic agents. Methods: Consecutive patients with acute ischemic stroke and receiving intra-arterial therapy were studied. An arterial sheath and an endovenous hypothermia catheter were placed into the femoral artery and vein. Hypothermia induction was performed with cold saline infusion. Goal temperature prior to recanalization was 35° or lower. Hypothermia was continued to a goal of 32° for 24 hrs. Controlled rewarming at 0.2°/hr was carried out. Shivering was controlled with skin counter warming, magnesium, dexmedetomidine, and meperidine. The BSAS scale was used to monitor shivering. Results: A total of 10 patients were studied, five women. Two patients with brainstem infarction were intubated, eight recieved sedation. Median age was 65 (range 49 - 80), NIHSS 16 (12 - 27), time from last known well 4 hrs (1 - 10) and ASPECTS 7 (6 - 10). Median door to venous needle time was 37 minutes (26 - 67) and arterial 40 minutes (30 - 70). Median time to reach 35° was 23 minutes (13 - 45). Eight patients reached 35° prior to recanalization. Median time to reach 32° was 171 minutes (122 - 235). Median BSAS was 1 (1-2). Median dose of dexmedetomidine infusion was 0.5 mcg/kg (0.2 - 0.8) meperidine 25mg (0 - 75) and magnesium 4gr (4-6). Two patients were treated for pneumonia prior to discharge. One DVT and one PE were diagnosed. No groin complications were recorded. Three patients died, two after withdrawal of care. Five patients were discharged to a rehabilitation facility and two to a skilled nursing facility. Conclusions: Combined endovenous hypothermia and intra-arterial therapy for acute ischemic stroke is feasible. In non-intubated patients shivering is well controlled and does not necessitate deep sedation or paralytic agents. Hypothermia catheter insertion does not delay intra-arterial recanalization. These data support the planning of a phase 2 trial to assess safety and optimum temperature goals.