The dose-dependent effect of tranexamic acid on epidural fibrosis after laminectomy: an experimental study on rats.

Objective: This study aimed to evaluate the dose-dependent efficacy of tranexamic acid (TXA) in preventing epidural fibrosis in a rat laminectomy model and explore its potential as a therapeutic intervention for postoperative fibrosis in spinal surgery. Methods: In this experimental animal study, 32 female Wistar-Albino rats were randomized into four groups (control, 10 mg/kg TXA, 30 mg/kg TXA, and 100 mg/kg TXA; n=8 per group). Following a standardized laminectomy procedure, TXA was administered intravenously as a loading dose through the tail vein prior to surgery. The rats were sacrificed at the 4th-week post-surgery, the lumbar vertebrae were excised en bloc, and epidural fibrosis, inflammatory cell density, and fibroblast density were assessed histologically. Results: High-dose TXA (100 mg/kg) significantly reduced epidural fibrosis compared to the control (p=0.004), 10 mg/kg (p=0.002), and 30 mg/kg TXA groups (p=0.03). While the 30 mg/kg group showed lower epidural fibrosis grades compared to the control, the difference was not statistically significant. No significant differences were observed in inflammatory or fibroblast densities across groups. Conclusion: High-dose TXA (100 mg/kg) effectively reduced epidural fibrosis in a dose-dependent manner, demonstrating potential as a systemic therapeutic option to improve postoperative outcomes in spinal surgery.