Neuromodulation in the Treatment of Postoperative Epidural Fibrosis: Comparison of the Extent of Epidural Fibrosis and the Effect of Stimulation

Abstract

The goal was to prove that when a cohort of patients is chosen precisely, dorsal column stimulation provides significant improvement to quality of life. We studied a cohort of 50 patients with the history of failed back surgery syndrome coupled with epidural fibrosis (EF). A percutaneous implantation technique was used in each of the 50 patients. The study group was composed of 20 women and 28 men aged 26-67 years (mean age 49). A prospective observational questionnaire-based study was used. According to the methods, Ross's classification was adjusted to four degrees of scar size for our study objective. Despite this adjustment, it was not possible to statistically evaluate our research, due to very similar results in Groups I, III and IV. Patients without epidural fibrosis were assigned to Group 0, and patients with EF of different ranges were assigned to Group 1. The mean change in visual analogue scale ΔVAS after our division into Group 0 was 4.82; for Group 1 it was 6.13. Evaluation of EF and ΔVAS correlation by paired t-test shows a statistically higher effect of spinal cord stimulation (SCS) in the epidural fibrosis group, compared to group 0 without postope-rative epidural fibrosis (p=0.008). The extent of epidural fibrosis is an important factor for Failed back surgery syndrome (FBSS). FBSS is the basis for the existence of neuropathic pain after lumbar spinal surgery. There is clear evidence of a correlation between patients with epidural scar formation on MR scan and the effect of dorsal column stimulation.