Attilio Della Torre, Domenico La Torre, Paola Lacroce, Angelo Lavano
Peridural fibrosis is considered cause of recurrent pain after lumbar laminectomy and discectomy (FBSS): it occurs in direct consequence of surgery and interests peridural and periradicular space both posterior and anterior. Its extension is directly proportional to the size of the bone defect and the area of surgical dissection: Incomplete hemostasis with presence of large epidural hematoma favors its extension over the limits of the bony defect. The fibrosis would derive from the damaged annulus during the excision of disk, from the inferior surface of the muscles overlying the dura, from the retention of cotton fragments in the operating field or from irritating material coming from residual of the nucleus pulpous.
Advanced hypotheses about the role of the peridural fibrosis in pain genesis are the neuromechanic, the intraneural fibrosis and demyelination, the release of chemical mediators from residues of nucleus pulpous. The prevention of scar formation is based on two factors: correct surgical technique and employment of materials of interposition. Materials of interposition may be biologic and no biologic. Biologic materials used are free fat graft, pedicle fat graft, ligamentum flavum and dura. No biologic materials are porous (gelatine sponge, avitene, bone wax) and non-porous (dacron, polymethylmethacrylate, espanded polytetrafluoroethilene, hyaluronic acid, carbohydrate polymer gel and carboxymethylcellulose gel).