Prevention of epidural scarring after microdiscectomy: a randomized clinical trial comparing gel and expanded polytetrafluoroethylene membrane

Abstract

A randomized clinical trial compared two materials used to prevent epidural scarring after microdiscectomy. To determine whether ADCON-L Gel (ALG) or Preclude Spinal Membrane (PSM) was more effective in preventing scarring, reducing pain, and improving quality of life postoperatively. Postdiscectomy syndrome may result from epidural scarring. Various materials have been used in attempts to prevent this problem, but none have provided optimal results. Previous laboratory and clinical studies have found ALG and PSM to be effective, but none compared the two materials. Thirty-one patients undergoing primary microdiscectomy were randomly assigned to receive either ALG or PSM. Postoperatively, patients were evaluated by magnetic resonance imaging (MRI), with contrast, for volume and rostral-caudal extent of scar tissue and nerve root involvement. Back and leg pain and quality of life were assessed by neurologic examinations and standardized patient surveys. Findings at any reoperations were recorded. Results in the PSM (n = 18) and ALG (n = 13) groups were compared statistically. No operative or postoperative complications occurred. Two patients in each group required reoperation. MRI at 6 months showed no, mild or mild-moderate scarring in most patients, with no significant differences between the ALG and PSM groups in scar volume and extent or nerve root involvement. Neurologic examinations and patient surveys showed substantial reductions in pain over time in both groups but no significant differences between groups. PSM was easy to see and remove at reoperation. PSM and ALG are equally effective in preventing epidural scarring associated with postdiscectomy syndrome.

Figures

Fig. 1

Histologic image showing the inner, nonporous surface (up) and the outer, porous surface (bottom) of a PSM that had been implanted for 6 months. While there is no scar tissue visible on the inner surface, abundant fibroblasts are present within the material on the outer surface (magnification 33× Milligan’s trichrome stain)