Rapid induction of brain hypothermia by endovascular intra-arterial perfusion

Abstract Objectives: Achieving rapid, brain cooling has potentially important clinical implications. To investigate potential practicalities, we induced brain hypothermia in canines by perfusing cooled crystalloid solution into the carotid artery using an extracorporeal cooling-filtration system. Methods: Ringer's solution cooled to ∼6.5°C was infused at a rate of 3 ml/kg/min for 30 minutes into the right common carotid artery through an angiographic catheter via the right femoral artery in six adult canines (13.81 ± 0.60 kg). Excessive fluid was ultrafiltrated through a venovenous extracorporeal circuit via the right femoral vein. Temperature was monitored in the cerebral hemispheres, the rectum and the vena cava. The extracellular lactate concentrations were measured by microdialysis in the frontal lobes. Results: Right brain temperature decreased to 33.6 ± 2.0°C from 37.7 ± 1.1°C 30 minutes after initiation of perfusion, while left brain and rectal temperatures were 34.3 ± 1.7 and 34.1 ± 1.3°C, respect...