Postoperative Epidural Fibrosis

Abstract

Epidural fibrosis (EF) is defined as nonphysiologic scar formation, usually at the site of neurosurgical access into the spinal canal, in intimate vicinity to and around the origin of the radicular sheath. From the very onset, EF behaves as a reparative inflammation causing, as a rule, clinical problems of characteristic nature and dynamism (pain). Treatment for EF, the role and mode of application of corticosteroids for EF management are, to this day, a moot point in algesiologic literature. The authors conducted a prospective study designed to obtain new data for assessing the anti-inflammatory effects of corticosteroids with special regard to the part played by steroids in the development of EF. The study also aimed at rating EF in terms of its effects on the intensity and character of the patient's symptoms after surgery for herniated intervertebral disc in the lumbar region. A double-blind prospective study was conducted to investigate a cohort of 200 patients requiring surgical treatment for intervertebral disc hernia (hernia disci intervertebralis). The patients were randomly and blindly divided into 2 groups, one on peroperatively applied local doses of a mix containing corticosteroids, the other without such medication. All the requirements of a double-blind study, including statistical assessment of the results, were observed throughout the diagnostic and therapeutical processes. The results were processed relative to the: clinical finding, subjective intensity of symptoms rated on a visual analog scale, radiographic finding (magnetic resonance imaging: plain and after contrast medium application). A statistical comparison of the clinical picture in the 2 surgically treated groups failed to reach statistical significance. Nevertheless, a trend toward better clinical picture in the steroid mix group was observed. Paradoxically, when statistically compared, the rate of EF build-up was found greater in the steroid-treated group. A 5% statistical significance was established in the correlation between the presence of EF and the patients' subjective rating (difference between input and output visual analog scale).