Intrathecal ketorolac pretreatment reduced spinal cord ischemic injury in rats

Paraplegia caused by spinal cord ischemic injury remains a potential complication of surgical repair of thoracoabdominal aortic aneurysms. Studies suggest that cyclooxygenase (COX) contributes to ischemic neuronal damage and that COX inhibitors may reduce injury. In this study, we examined whether intrathecal pretreatment with ketorolac, a nonselective COX inhibitor, had a protective effect against ischemic spinal cord injury in rats. Rats were randomized to receive either intrathecal normal saline, ketorolac 30 mu g, or ketorolac 60 mu g (n = 6 rats per group) 1 h before spinal cord ischemia (intraaortic balloon occlusion combined with proximal arterial hypotension for 11 min). Another 6 rats served as the sham-operated controls. Ischemic injury was assessed by hindlimb motor function and by histopathological changes in the lumbar spinal cord at 24 h after the ischemic insult. The other 20 rats (n = 10 per group) were used in the second experiments to evaluate the safety of this drug. Survival of rats was recorded 28 days after reperfusion. Intrathecal pretreatment with 60 mu g of ketorolac significantly reduced neuronal death and improved hindlimb motor function, and the long-term survival was similar to that in the control group. The results suggest that intrathecal ketorolac may be of therapeutic potential for preventing spinal cord ischemic injury during thoracoabdominal aortic surgery.