An investigational study of a dual‐layer, chorion‐free amnion patch as a protective barrier following lumbar laminectomy in a sheep model. (18th July 2019)

• Record Type: Journal Article
• Authors: Cunningham, Bryan W.; Seiber, Breanna; Riggleman, Jessica R.; Van Horn, Margaret R.; Bhat, Archana
• Is Part Of: Journal of tissue engineering and regenerative medicine. Volume 13:Number 9(2019)
• Page Start: 1664
• Page End: 1671
• Publication Date: 2019-07-18
• Subjects: failed back surgery syndrome -- human amniotic membrane -- amnion patch -- lumbar laminectomy -- fibroblast -- scar tissue -- epidural fibrosis -- neurohistopathological response; Tissue engineering -- Periodicals; Regeneration (Biology) -- Periodicals; 610.28
• DOI: 10.1002/term.2920
• Languages: English
• ISSNs: 1932-6254

Abstract

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.