[Effect of focal irrigation with mild hypothermic artificial cerebral spinal fluid on the spinal ischemia/reperfusion injury].

To investigate the effect of focal irrigation with mild hypothermic artificial cerebral spinal fluid on the spinal ischemia/reperfusion injury.Eighteen health male New Zealand white rabbits were randomly divided into three groups: normal control group (Group NC), spinal ischemia-reperfusion group (Group SIR) and focal irrigation with mild hypothermic artificial cerebral spinal fluid group (Group FI). The rabbits in Group SIR and Group FI were subjected to spinal ischemia/reperfusion injury by clamping the infrarenal abdominal aorta. The rabbits in Group FI received focal irrigation with 25 degrees C artificial cerebral spinal fluid during the spinal ischemia period. The mean arterial pressure (MAP) and cerebral spinal fluid pressure (CSFP) were continuously measured during the ischemic/reperfusion processes. The neurological conditions of the rabbits were assessed at 24 h, 48 h and 72 h after reperfusions. The spinal cords were harvested 72 h after reperfusions for histological analysis.The MAP and CSFP in Group NC remained stable. The MAP in Group SIR and Group FI decreased continuously in the first 30 min of spinal ischemia period and 30 min after reperfusion. The CSFP in Group SIR increased continuously in the first 10 min of spinal ischemia and was higher than the baseline and those in Group NC. The CSFP in Group FI decreased to 3.8 mmHg (1 mmHg = 0.1333 kPa) at the beginning of spinal ischemia, and remained at 3-5 mmHg until 20 min after reperfusions. Group FI had better neurological outcomes and less severe pathological changes than Group SIR measured at 72 h after ischemia/reperfusion.Focal irrigation with mild hypothermic artificial cerebral spinal fluid can decrease CSFP during spinal ischemia/reperfusion and protect spinal cords against ischemia/reperfusion injuries.