A Study of Preservation of Spinal Cord in Spinal Cord Ischemia of the Rabbit Comparison of Aprotinin and Pentoxifylline

ABSTRACT

PURPOSE: The complications of ischemic spinal cord injury on the descending and thoracoabdominal aorta remain a problem in spite of surgery and anesthesia advance. The protective effects of aprotinin and pentoxifylline was assessed from a rabbit spinal cord ischemia model in order to prevent ischemia reperfusion injury from the spinal cord. METHOD: In 36 rabbits, left vertical flank incision and retroperitoenal approach were done and ischemia was induced with clamping of the aorta just distal to left renal artery and proximal to aortic bifurcation for 20 min. In Group A, Aprotinin was given 30,000 KIU/kg was given as a intravenous injection after anesthesia, and was followed by 10,000 KIU/hr by continuous infusion in group A (n=12). Also in group B, Pentoxifylline 40mg/kg was given as a intravenous injection after anesthesia, and was followed by 30 mg/hr by continuous infusion in group B (n=12). Similar volume of saline solution was used in control group C (n=12). Physiological parameters were monitored in animals before aortic occlusion, during aortic occlusion, after aortic occlusion. Their neurological outcome was clinically evaluated up to 48 hour postischemia. After 48 hour of the operation, all rabbits' victim were induced and their spinal cord, abdominal aorta, and its branches were processed for histopathological examination. RESULT: Mean aortic pressure, heart rate and arterial blood gas analysis showed no statistical difference in 3 groups. Bladder function also revealed no statistical difference. The average motor function score was significantly higher in aprotinin group (group A) than control group (group C) at 24 (P=0.026) and 48 hour (P=0.018) after the ischemic insult. But the average motor function score was similar in pentoxifylline group (group B) and control group (group C) at 24 and 48 hour after the ischemic insult. Histological observations were revealed fewer ischemic damage in aprotinin group (group A) than control group (group C) but in pentoxifylline group (group B) and control group (group C), ischemic damages were more than moderate degree. CONCLUSION: The results suggest that aprotininreduces spinal cord injury and preserves neurologic function in transient spinal cord ischemia of rabbits but pentoxifylline is not effective.