The effect of oophorectomy on epidural fibrosis after laminectomy: an experimental study in rats

Objective: The aim of this study was to examine the effect of oophorectomy in the formation of epidural fibrosis in a rat laminectomy model. Methods: Thirty-six 12-month-old adult female Sprague-Dawley rats were used in this study. Rats were evenly divided into two groups; oophorectomized and sham-operated. Bilateral oophorectomy was performed on the 18 rats in the oophorectomized group. Three weeks after oophorectomy, rats in both groups underwent complete bilateral laminectomy at the L2 and L3 vertebral levels. Rats were divided into 3 equal groups and sacrificed in groups of 4 at the 4th, 8t, and 12th weeks postoperatively and the lumbar spine excised en bloc, fixed and decalcified. Sections were stained with hematoxylin and eosin and Masson's trichrome were used to evaluate epidural fibrosis, acute inflammation, chronic inflammation, and vascular proliferation. Results: The mean histological sum grade of the epidural fibrosis was greater in the oophorectomized group (p>0.05). Conclusion: Endogenous estrogen could have an effect on epidural fibrosis formation after lumbar laminectomy in rats.