Selective Brain Cooling Via Thermoelectric Extravascular Blood Cooling of a Carotid Artery

Abstract

Abstract. Selective brain cooling (SBC) is achieved by cooling the carotid artery of rats with an extravascular thermoelectric concentrated cooling probe. The efficacy of this technique is established by directly measuring temperature at the brain, rectal/core, and intrajugular locations. The level of brain cooling achieved is compared against that of a conventional clinical hypothermia intervention, simulated with a cooling blanket placed on the rat's abdomen. With the probe, brain temperature decreased rapidly (4.19 ± 3.15 °C/h) and independently of the core (−0.84 ± 2.59 °C/h) when applying 0 °C. Histological evaluations of the carotid tissue and blood samples showed no adverse pathological changes from the technique. By contrast, systemic hypothermia via cooling blanket showed steep brain cooling (−8.22 ± 3.35 °C/h) at the expense of significant losses in core temperature (−15.31 ± 6.60 °C/h). Localized brain cooling as demonstrated with the probe allows increased controllability and potential for therapeutic use provided it is validated in larger animal models. A sophisticated SBC technique will enable future investigations into decoupling and reducing the detrimental side effects of systemic hypothermia from its benefits.