Morphological Patterns of Development and Prevention of Experimental Epidural Fibrosis

Abstract

Objective: To identify the morphological patterns of development and prevention of experimental epidural fibrosis based on the shape of the dural sac in the area of laminectomy. Methods: Male Wistar rats aged 4-5 months underwent laminectomy at the level of L6-S1. The animals were divided into two groups with 7 animals per group. In the main group (Group A) the animals were treated with Antiadhesin® gel applied to the wound to prevent the development of epidural fibrosis, while in the group of comparison (Group B), the gel was not applied. Another 7 healthy animals were used as a control group. The animals were taken out of experiment on the 28th day. Histological slides stained with hematoxylin-eosin were used to measure the width and length of the dural sac, its area, perimeter, and calculate its deformity index. Results: In group B at the level of laminectomy, the ratio of the width to length of the dural sac was significantly higher than in the control group (p<0.05), mainly due to the enlarged width, while the length did not change significantly. In group A these parameters did not differ from the control group, which indicated that application of Antiadhesin® prevented formation of a connective tissue scar which could compress the dural sac and cause its deformation. In group A in the area of surgical intervention, granulomas with Pirogov-Langhans cells were detected, both in the soft tissues and in the lumen of the spinal canal. These findings in perioperative tissues might be related to biocompatibility and indicate their reaction to a gel as a foreign body. Conclusion: In clinical practice optimal materials for the prevention of epidural fibrosis are missing. There is an obvious need for further research in order to obtain implants capable of inhibiting and reducing the formation of epidural fibrosis. Keywords: Dura mater, epidural fibrosis, prevention, experiment, laminectomy, Antiadhesin®.