Experimental evaluation of femoral vein grafts and platelet-rich fibrin for reducing epidural fibrosis in a rat laminectomy model

Epidural fibrosis (EF) refers to the non-physiological scar formation at the site where a surgical incision is made to access the spinal canal. This condition often results in functional disability and pain following spinal surgery and is a common and difficult-to-treat contributor to Failed Back Surgery Syndrome (FBSS). This study aimed to investigate the effectiveness of platelet-rich fibrin (PRF) clots, vein grafts, or a combination of both in reducing epidural fibrosis after laminectomy in rats. One hundred adult Sprague-Dawley male rats, weighing 300 ± 55 g, were equally and randomly assigned into five groups (n = 20): the control, laminectomy, PRF, vein graft, and PRF/vein graft groups. The control group consisted of normal, untouched rats that did not undergo anesthesia, surgical exposure, laminectomy, or sham operation. Lumbar laminectomy was performed at L3-L5 in the laminectomy, PRF, vein graft, and PRF/vein graft groups. On postoperative day 30, outcomes were assessed in two predefined independent subsets within each group. Ten rats per group were used for macroscopic epidural adhesion scoring after surgical-site reopening, whereas the remaining ten rats per group were used for histopathological, morphometric, and qRT-PCR analyses of IL-6 and TGF-β1 expression. Therefore, the effective analytical sample size was n = 10 animals per group for each endpoint category, not n = 20 per group. The primary endpoint was histological epidural fibrosis score at day 30; all other macroscopic, morphometric, inflammatory, and molecular outcomes were secondary endpoints. The EF area was significantly reduced in all treatment groups compared with the laminectomy group. Overall, the vein graft-containing groups showed the strongest reductions in adhesion, scar density, dura mater thickness, and IL-6/TGF-β1 expression. The combined PRF/vein graft treatment was generally more favorable than PRF alone but was often comparable to vein graft alone, indicating that a consistent superiority of the combined approach over vein graft alone was not demonstrated. Vein graft-containing treatments reduced histological and molecular markers of epidural fibrosis in this rat laminectomy model. The combined PRF/vein graft approach showed favorable anti-inflammatory and anti-fibrotic effects, but it was not consistently superior to the vein graft alone across all assessed endpoints. Therefore, the findings should be interpreted as preliminary preclinical evidence supporting further investigation of vein graft-based local barrier strategies rather than direct evidence of a superior combination therapy or a clinically ready approach.