Comparative analysis of a fully-synthetic nanofabricated dura substitute and bovine collagen dura substitute in a large animal model of dural repair

Abstract

Objective: Dura substitutes are commonly required to repair the dura mater during routine neurosurgical procedures. Biologic materials composed of xenogenic collagen represent the most prevalent dura substitute, yet often incite undesirable tissue responses that impair wound healing. Synthetic materials that overcome the shortcomings of existing products and facilitate effective and reliable repair of native dura are needed. The aim of the present study was to compare the performance of a novel synthetic non-biologic nanofabricated dura substitute to a crosslinked bovine collagen dura substitute as a means of facilitating successful dural repair. Patients and methods: The biocompatibility and efficacy of fully-synthetic nanofabricated dura substitute (Cerafix® Dura Substitute, Acera Surgical, Inc., St. Louis, MO) and bovine dural substitute (DuraMatrix™ Collagen Dura Substitute Membrane, Stryker, Inc., Kalamazoo, MI) was compared in a rabbit duraplasty model. Bilateral dural defects were repaired with either material and secured with non-tension sutures. Animals were monitored post-operatively for neurological sequelae and cerebrospinal fluid leak. Repair sites were explanted 4 weeks after implantation and evaluated by histopathology to assess neoduralization, cortical adhesion, implant resorption, local inflammation, and tissue response. Results: Both the fully-synthetic and bovine collagen dura substitutes were effective in repairing dural defects and preventing cerebrospinal fluid leakage post-operatively. Histopathology revealed increased neoduralization and reduced cortical adhesion in defects repaired with the nanofabricated synthetic dural substitute versus defects repaired with the bovine collagen membrane. Histological analysis further demonstrated that the bovine collagen dural substitute induced a greater inflammatory response than the fully-synthetic nanofabricated material, with greater infiltration of inflammatory cells in bovine collagen implants at the terminal time-point. Conclusions: Synthetic nanofabricated dural substitute and bovine collagen dural substitute demonstrated effective repair of induced dural defects and successfully prevented CSF leakage without infection or damage to underlying brain tissue. Nanofabricated dura substitute exhibited increased neoduralization, reduced cortical adhesions, and progressive resorption compared to the bovine collagen membrane. Fully-synthetic nanofabricated dura substitute further demonstrated less inflammation, irritation, and fibrosis than the bovine collagen material. Nanofabricated dura substitute thereby provides a unique non-biologic option in dural repair procedures, and offer reduced risk of inflammation and adhesions commonly associated with traditional xenogenic collagen products. Keywords: Dura substitute, Rabbit duraplasty model, Synthetic materials, Nanofabricated dura substitute, Dural repair procedures, Cerafix dura substitute