Effect of single-nanofibrous materials for epidural scar prevention after laminectomy: An experimental study in an animal model.

Abstract

PURPOSE: To evaluate whether nanofibrous anti-adhesion membranes reduce epidural scar formation after lumbar laminectomy in a rabbit two-level model, comparing a non-degradable PVDF membrane with a degradable PCL membrane. METHODS: Adult rabbits underwent L1 laminectomy (internal control) and L5 laminectomy with membrane implantation (PVDF or PCL). The primary endpoint was epidural scar width (mean and maximum) on histology in paired within-animal comparisons (L5 vs. L1). For PVDF, we used a one-sided paired Wilcoxon test (α = 0.05); effect sizes are reported as Hodges–Lehmann median paired difference with 95% CI. The PCL group (small n) was analysed descriptively. RESULTS: PVDF implantation yielded consistently narrower scars than the paired internal control, reaching statistical significance (exact p = 0.016). The magnitude of reduction, although directionally favourable, did not meet the prespecified threshold for clinical relevance (≥ 90% narrowing). In the PCL group the material was largely resorbed by 12 weeks and was frequently associated with adhesive tissue bridges and neovascularization; due to the limited sample size, these findings are descriptive. CONCLUSIONS: A non-degradable PVDF nanofibrous membrane significantly reduced epidural scar width in a paired rabbit model but fell short of the predefined clinically meaningful reduction. Degradable PCL demonstrated rapid resorption with unfavourable adhesion morphology. These data support further optimization of membrane design and durability before clinical translation.