Abstract 1795: Erythropoietin exerts Neuroprotection during Deep Hypothermic Circulatory Arrest
Objectives: Permanent mild to severe brain injury with neurologic and developmental sequelae remain a significant source of postoperative morbidity in Cardiovascular Surgery. Preconditioning with Erythropoietin (Epo) has recently been shown to protect neurons from ischemic injury. This study evaluates whether systemic Epo treatment mediates brain protection during global ischemia which is induced by deep hypothermic circulatory arrest (DHCA) in a chronic porcine model.
Methods: Sixteen pigs (42 ±3 kg) randomly assigned into two groups (n =8) were subjected to 60 min of DHCA at an intracerebral temperature of 20°C. The animals of the Epo group were treated perioperatively with 500 IU/kg of recombinant human erythropoietin (rhEpo) on 3 consecutive days beginning the day before surgery. Intracerebral monitoring was performed by subcortical microdialysis, brain tissue oxygenation, measurement of brain temperature and intracranial pressure. Neurologic recovery was evaluated daily. Perioperative S100β protein serum level was determined. The brains were harvested on the 6th postoperative day after perfusion fixation. Multiple brain regions were investigated histologically for hypoxic-ischemic damage.
Results: Epo treated animals tended to a more complete and rapid neurological recovery. In contrast, none of the animals in the control group achieved complete neurological recovery. The subcortical brain microdialysis detected significant increase of glycerol and lactate concentrations in both groups (P<0.0001) with significantly higher concentrations in the brain of control animals (P< 0.05). S100β protein tended to be higher in the control group (P = 0.08). Brain infarction was detectable in all survived control animals but only 2 Epo animals
Conclusion: These results suggest the beneficial neuroprotective effect of Epo in this model of global brain ischemia induced by 1 hour of hypothermic circulatory arrest.