Previous clinical studies have demonstrated a significant association between the presence of postlaminectomy fibrous tissue formation and the recurrence of low back and radicular pain.
Many materials have previously demonstrated to inhibit epidural fibrosis after laminectomy in animal models. As known, several structural analogues of proline have been shown to be incorporated into proteins in place of proline. As a consequence, the proliferation of cells in culture and the extracellular deposition of collagen in animal systems are reduced. The current study was designed to measure the effect of cis-4-hydroxy-L-proline (cis-4-OH-L-proline) on postlaminectomy epidural fibrosis development in a rat model.
L4 laminectomy was performed on 150-200 gr weightened 27 rats. 6 rats were excluded from statistical analysis for different reasons (3 for macroscopic evaluation, 2 for sliding of hydrogel from the operation level, 1 for exitus). There were no complications after surgery and no neurological deficits were seen. Exposed dura at L4 level was covered with following: 1. Control group 2. Hydroxyethylmetacrylate (HEMA) hydrogel 3. cis-4-hydroxy-L-proline+HEMA hydrogel. 3 weeks after surgery, the rats were sacrified and at L4 level, the spinal columns were harvested, decalcified and tranverse sections w er e prepared with hematoxcylin-eosin and Masson’s trichrome stains for histologic analysis. The transverse sections were evaluated for epidural fibrosis development by light microscopy and the epidural fibrotic areas were measured with Zeiss Axioskop visual analysis morphometry program in computer.
As compared with control and HEMA hydrogel groups, the significant antifibrotic effect was found in our experimental group in point of nerve root entrapment and sublaminar fibrosis and the results were confirmed the usefulness of cis-4-hydroxy-L-proline hydrogel in predicting the degree of postlaminectomy epidural fibrosis.
Keywords: Epidural fibrosis, laminectomy, cis-4-hydroxy-L-proline