[Protective effect of epidural cooling upon ischemic spinal cord injury]

To evaluate the protective effect of epidural cooling on ischemic spinal cord injury.

Fourteen healthy hybrid dogs were randomly divided into two groups: control group (n = 8) and experimental group (n = 6). Spinal cord injury was induced by double aortic cross-clamping for 40 minutes. Before the clamping, the cerebrospinal fluid temperature of the animals in experimental group was decreased to 30 degrees C +/- 1 degrees C by epidural cooling until the aorta was unclamped for 5 minutes. Three days after the operation, the function of the hind limbs of the animals was evaluated by Tarlov's scale and histological examination of the spinal cord was made.

Six dogs showed complete paraplegia (grade 0) and two showed paresis (grade 1) in the control group. The neurological outcome of the experimental group was much better than that in the control group (H = 10.68, P = 0.001). The neurological function of 4 dogs in the experimental group was in grade 4, and one in grade 3. Histological examination revealed hemorrhage of gray matter, degeneration and necrosis of neurons, and severe demyelination of myelinated nerve fibers in the spinal cord from T10 to sacral segments in dogs with paraplegia. The changes in spinal cord were slight in the dogs without severe neurological injury.

Local hypothermia of spinal cord by epidural cooling provides effective protection against ischemic spinal cord injury in dog.