An investigational study of a dual‐layer, chorion‐free amnion patch as a protective barrier following lumbar laminectomy in a sheep model

Abstract

The inherent properties of the human amniotic membrane (HAM) suggest its potential for use as a physical barrier during surgery to protect neural elements and vessels from the surrounding environment. The objective of this study was to evaluate the effect of a dual‐layer, chorion‐free amnion patch (DLAM; ViaShield®, Globus Medical Inc., Audubon, PA, USA) processed from HAM as a protective barrier following lumbar laminectomy in a sheep model. A multiplex immunoassay was performed to quantify the inherent cytokines present in the amnion after processing. Twelve skeletally mature female crossbred Suffolk sheep were randomly divided into two equal post‐operative periods (4 and 10 weeks). Each sheep underwent a laminectomy at L3 and L5, and one of the surgical sites randomly received the DLAM treatment. At each postsurgical time point, the extent of epidural fibrosis and neurohistopathological responses at the laminectomy sites was assessed based on epidural fibrosis–dura tenacity scores and decalcified histology, respectively. Immunoassay results showed that inflammatory mediators and immunomodulatory cytokines were present in the amnion after processing, but no proangiogenic cytokines were detected. At 10 weeks, tissue tenacity was significantly less in the DLAM treatment group when compared with the operative control (1.2 ± 0.4 vs. 2.8 ± 0.4, p < 0.05), demonstrating the ability of DLAM to act as a barrier and cover the dura. Gross observations showed fewer fibroblasts in the DLAM group in comparison with the control at both post‐operative time points. Fibroblast infiltration analysis indicated that at both 4 and 10 weeks, there were significantly more infiltrated fibroblasts in the operative control sites than in the DLAM‐treated sites, expressed as a percentage of the total number of fibroblasts present (4 weeks: 72.3 ± 10.2% vs. 10.8 ± 10.1%, p < .05; 10 weeks: 84.9 ± 15.8% vs. 43.1 ± 11.6%, p < .05). Additionally, fibroblasts travelled further into the dura in the operative control group compared with the DLAM‐treated group at both time points. In conclusion, this study found that DLAM reduced fibroblast infiltration and tissue tenacity following lumbar laminectomy in a sheep animal model. These findings support the potential use of DLAM in clinical practice as a protective barrier for neural elements and anterior vessels.

Chronic pain after spine surgery: Insights into pathogenesis, new treatment, and preventive therapy

“…Human birth tissue products may exert multiple beneficial effects for post-laminectomy epidural adhesion, including a physical barrier to reduce fibroblast infiltration and consequent epidural fibrosis, the limitation of inflammation and disc degeneration, reduction of pain, and promotion of regeneration. Similarly, a dual-layer, chorion-free amnion patch (DLAM; ViaShield®, Globus Medical Inc., Audubon, PA, USA), which was developed from human amniotic membrane, effectively reduced fibroblast infiltration and tissue tenacity after lumbar laminectomy in sheep [ 132 ]. Recently, a new bacterial cellulose ( bc ) anti-adhesion membrane, composed of exosomes from human umbilical cord mesenchymal stem cells, also demonstrated the prevention effect on epidural fibrosis post-laminectomy in a rabbit model, without notable cytotoxicity [ 133 ].…”

LncRNA-COX2 inhibits Fibroblast Activation and Epidural Fibrosis by Targeting EGR1

“…A most relevant hypothesis is that the fibroblasts proliferated from their own mitosis and migrated from adjacent mesenchymal cells of perivertebral muscles and blood vessels to mechanically contract and compress the spinal roots and the neural sac [7,8]. To control surgical injury repair under regenerative condition other than scar formation, approaches including various agents and materials have been demonstrated to attenuate the epidural fibrosis [9][10][11][12][13], but few of them have been applied into clinical practice due to uncertainty of its mechanism, thus highlighting the need for unremitting efforts to verify new biological pathways that can promise to be an adjunctive target for epidural fibrosis.…”

<p>Regulation of ERK1/2 and SMAD2/3 Pathways by Using Multi-Layered Electrospun PCL–Amnion Nanofibrous Membranes for the Prevention of Post-Surgical Tendon Adhesion</p>

“…Moreover, its unique structure makes it an ideal biological material. 9,10 Clinical and basic research on amnion have been conducted for nearly 100 years. As early as 1913, Stem used amniotic membrane for repairing skin burns and ulcer wounds.…”