OBJECTIVESTo observe the protective effect of retrograde venous perfusion of cryogenic liquid via accessory hemiazygos vein and treated with resveratrol on spinal cord injury and evaluate the expression changes of microtubule-associated protein 2 (MAP-2) after spinal cord ischemia reperfusion injury (SCII) in swine.

METHODSEighteen swine were divided into 3 groups: group I/R (n = 6, operation group), group CL (n = 6, retrograde venous perfusion of cryogenic liquid), group CL+Res (n = 6, retrograde venous perfusion of cryogenic liquid and treated with resveratrol after ischemia). In the group I/R, the aorta was clamped for 60 minutes and then removed. In the group CL and CL+Res, 9 g/L cold (4 °C) saline solution (perfusion rate, 16.65 ml/min) was infused into the accessory hemiazygos vein during ischemia.In the group CL+Res, the swine were treated with resveratrol (10 mg/kg) after spinal cord ischemia. Arterial pressure, blood gas analysis and the spinal canal and nasopharyngeal temperature changes were monitored during the surgery. Nervous function were assessed at 6 hours, 1, 2 days, 1, 2, 4 weeks and MAP-2 expression were detected at 4 weeks after reperfusion by using Western blot analysis in spinal cord tissue.

RESULTSAfter operation 18 swine were all survival. Behavioral scores of all groups decreased until 1 week after reperfusion and increased as time went by. The scores of group CL and CL+Res were higher than group I/R (F = 8.612, 17.276 and 11.985, P = 0.035,0.011 and 0.023) at 6 hours, 1, 2 days, group CL+Res were higher than group CL(P = 0.021) at 1 days after surgery. After descending aortic cross clamping, the spinal canal and nasopharyngeal temperature were obviously decreased in all groups and dropped to the lowest at 60 minutes after ischemia and 20 minutes after reperfusion in group I/R and the other groups respectively(F = 23.187-55.029, P < 0.01).In group CL(0.54 ± 0.26) and CL+Res (0.66 ± 0.31), the MAP-2 expression were higher than group I/R(0.37 ± 0.18) (F = 9.381, P = 0.037) , and the level in group CL+Res was higher than in group CL (P = 0.021) .

CONCLUSIONRetrograde venous perfusion of cryogenic liquid via accessory hemiazygos vein and treated with resveratrol can relieve the ischemia-induced spinal cord injury in swine.