The effects of hyperbaric oxygen treatment in reducing epidural fibrosis after lumbar laminectomy in rats

Using an experimental animal model of lumbar laminectomy surgery, this study aims to evaluate the effects of hyperbaric oxygen therapy on both epidural fibrosis formation and pain.For this purpose, 24 adult Wistar rats underwent lumbar laminectomy surgery at L5 and L6 level. Following the surgical procedures, rats were divided into three groups randomly and rats in the control group received no further treatment. Rats in the other two groups received hyperbaric oxygen treatment at 2,5 absolute atmosphere pressure for 3 and 7 days, respectively. Hind paw mechanical withdrawal thresholds were measured using von Frey applicators during the six weeks follow up period. At the end of the 6th week all animals were killed and their spinal segments that underwent lumbar laminectomy were harvested for the histopathological grading of epidural fibrosis and fibroblast density.There was no statistically significant difference among the groups regarding both the extent of peridural fibrosis and fibroblast density; however, the extent of epidural fibrosis in hyperbaric oxygen groups was less than the control group. On the other hand, animals in the hyperbaric oxygen groups demonstrated significantly better hind paw mechanical withdrawal responses compared to the control group on 4th and 6th weeks of the observations.Hyperbaric oxygen therapy which have been proven useful for different indications reduced epidural fibrosis that leads failed back surgery syndrome and pain resulting from it. Further studies with larger cohorts and longer follow up durations are required to reproduce these effects.