Protective use of N-methyl-d-aspartate receptor antagonists as a spinoplegia against excitatory amino acid neurotoxicity

Paraplegia is a devastating complication during surgical repair of the thoracic and thoracoabdominal aortas. Excitatory amino acids neurotoxicity through the N-methyl-d-aspartate (NMDA) receptor is no doubt the pathologic hallmark of ischemic and postischemic spinal cord injury. Systemic administration of either a competitive or noncompetitive NMDA antagonist has been reported to have neuroprotective effect, in terms of preoperative treatment, with dose-related central sympathomimetic and sedative effects. Local administration, particularly of a noncompetitive NMDA antagonist, infused segmentally after aortic clamping could therefore be a potent intraoperative pharmacologic strategy to minimize the effective dose that retains NMDA antagonism without undesirable adverse effects. Our ability to reproduce this model could facilitate pharmacologic prevention or provide a new surgical technique as a spinoplegia for NMDA receptor-mediated neuronal injury.