Changes of CSF and spinal pathomorphology after high-concentration ozone injection into the subarachnoid space: an experimental study in pigs.

BACKGROUND AND PURPOSE Our aim was to explore the changes of CSF and spinal pathomorphology after high-concentration ozone injection into a pig's subarachnoid space. MATERIALS AND METHODS Eight experimental pigs were randomly divided into 4 groups (n=2 in each group). In groups A, B, C, and D, animals were sacrificed for pathology 1 day, 1 week, 1 month, and 3 months after the injection, respectively. Ozone (10 mL, 90 microg/mL) was injected along the lumbar 4-5 interspace into the subarachnoid space with a 21-ga Chiba needle under fluoroscopy. CSF collection and CT and MR imaging were performed before injection and 30 minutes, 1 week, 1 month, and 3 months after injection, respectively. The spinal cords were observed macroscopically and microscopically. RESULTS No serious behavior abnormalities were observed in any animals. There were no abnormalities in CSF and spinal cords pathologically and radiologically after injection. CONCLUSION Our initial study suggests that high-concentration ozone injection into a pig's subarachnoid space will not cause serious sequelae such as chemical arachnoiditis and necrosis of the spinal cord, and this finding provides evidence of the safety of ozone inadvertently injected into subarachnoid space in the clinical treatment of disk herniation.