A carbohydrate polymer that effectively prevents epidural fibrosis at laminectomy sites in the rat

We demonstrate that a carbohydrate polymer, designated GL402, effectively inhibits epidural fibrosis in a rat laminectomy model. A total laminectomy in Lewis rats was performed at lumbar vertebrae 3 and 5. GL402 or phosphate buffer solutions in gelatin sponges were applied to the laminectomy sites. Epidural fibrosis was measured, using a double-blind protocol, 2 weeks postoperatively either by gross anatomical evaluation (blunt dissection) or by histological evaluation. Local application of GL402 produced nearly complete inhibition of epidural fibrosis, whereas extensive scar formation and bone growth occurred after local application of buffer or other purported anti-fibrotics. In laminectomy sites treated with GL402 the dura mater was essentially free of adhering fibrosis and bone growth was dramatically decreased. With reduction of postlaminectomy fibrosis, the spinal nerve roots are more mobile and therefore may be less prone to recurrent nerve root compression. The dramatic reduction of epidural fibrosis by GL402 will make reoperative disc surgery safer due to greater accessibility of the laminectomy site. This compound may be useful in preventing surgical adhesions in other sites as well.