Therapeutic hypothermia is a well-established therapy with clear neuroprotective effect. It has been widely used in the aid of neonatal hypoxic encephalopathy and cardiac arrest. Researchers have been trying to apply therapeutic hypothermia to the treatment of acute ischemic stroke for decades. However, many hypothermia induction methods that proved effective in rodent transient cerebral ischemia models have encountered challenge in clinical translation. The reason may lie in the differences between rodents and humans in brain volume and metabolism. as well as the mismatch between hypothermia induction methods performed in clinical and preclinical trials. Therefore, how to induce hypothermia safely and efficiently in an appropriate model is the key to the clinical translation of therapeutic hypothermia.
In this study, a rhesus monkey model of transient ischemia-reperfusion was established to simulate the pathogenesis and treatment of ischemic stroke by placing/withdrawing endovascular coils. Arterial blood was extracted from the left femoral artery of the monkeys, passed through a heat-exchange unit developed by the team, and then transfused directly into the recanalized cerebral artery via a microcatheter placed previously in the right femoral artery. This method could reduce brain temperature rapidly (down to 34°C within 5 min) while maintaining relatively higher core body temperature during 2 h procedure. More importantly, no adverse effects of systemic hypothermia such as shivering and infection were observed, indicating the safety of this method.
To evaluate the neuroprotective effect of cold autologous blood, Chen et al. used magnetic resonance imaging (MRI) to evaluate the infarct volume of the animals. Targeted cold autologous blood transfusion effectively reduced infarct volume and infarct core expansion in the acute phase of ischemic stroke as shown on T2 sequence and diffusion weighted imaging (DWI). In addition, white matter integrity was preserved by hypothermia as evaluated with diffusion tensor imaging (DTI). Consist with reduced infarct volume, cold autologous blood also improved neurological function.
https://doi.org/10.1016/j.scib.2023.06.017
