May 25, 2014

SYNTHECEL Dura Repair

Christian Matula

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Fig 1: SYNTHECEL Dura Repair may be used as a dural substitute following neoplastic damage.

SYNTHECEL Dura Repair Dura Repair is a dural substitute based on biosynthesized cellulose technology. It is designed for the repair of dura mater during cranial or spinal surgery, following traumatic, neoplastic or inflammatory damage.

Unmet clinical needs in dural repair

Materials currently used for dura replacement include human tissues (e.g. pericranium or fascia lata), animal tissues, polymers and biosynthetic substances. However, use of these materials can be problematic. Autologous tissue grafts can perform well as they do not provoke inflammatory or immunological reactions, but can present difficulties in achieving watertight closure, formation of scar tissue, a graft material to close large dural defects and morbidity at the harvest site. Synthetics have been associated with deep wound infections, as polymers may become chronically colonized. Xenografts may cause adverse effects such as graft dissolution, encapsulation, foreign body reaction, scarring and the formation of adhesions. The development of adhesions between dura mater, cortex, temporalis muscle and galea following decompressive craniectomy can act as epileptic foci as well as increasing the surgical risk of subsequent cranioplasty. Additionally, xenografts have been associated with the transmission of viral infections and hydrodynamic complications including persistent CSF leakage, pseudomeningocele, aseptic meningitis and delayed hydrocephalus.

To function effectively, dural substitutes should:

  • Prevent CSF leakage

  • Minimise risk of infection

  • Have mechanical properties similar to human dura and good intra-operative handling properties

  • Have no harmful foreign body reaction

  • Be readily available

  • Be storable

  • Be biocompatible

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Fig 2a-d: Material composition: (a) Composed of biosynthesized cellulose and water, SYNTHECEL Dura Repair is similar in thickness to human dura; (b) Layers of biosynthesized cellulose (high magnification); (c) Interconnected cellulose fibres that comprise SYNTHECEL; (d) Cellulose fibers are naturally produced by Glucoacetobacter xylinus.

Development of SYNTHECEL Dura Repair

SYNTHECEL was developed as a superior dural substitute, with the aim to eliminate or reduce many of the adverse events associated with materials currently used for dura replacement (see "Details" below). SYNTHECEL Dura Repair is an implant based on biosynthesized cellulose technology. Cellulose pellicles of specified weight and cellulose content are produced by the bacterium Glucoacetobacter xylinus when propagated in nutritive culture media.

Comprised of non-woven, interconnected cellulose fibres, SYNTHECEL has excellent tensile strength and functions as a mechanical layer to protect and repair dural defects whilst preventing CSF leakage (Fig 3). SYNTHECEL is immunologically inert, allows healing without adhesion formation and avoids the complications inherent to the use of autologous tissue in duraplasty. SYNTHECEL is non-animal derived, meaning there is no risk of transmissible diseases.

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Fig 3: Investigational device exemption (IDE) intraoperative photograph showing a dural repair using SYNTHECEL Dura Repair (Courtesy of Barrow Neurosurgical Associates, Ltd.)

Clinical Performance of SYNTHECEL Dura Repair

Clinical studies have shown that SYNTHECEL Dura Repair is not inferior to other commercially available dural replacement products in terms of surgical site infection, wound healing assessment or radiologic endpoints (absence of pseudomeningocele and CSF fistula) (1). Furthermore, SYNTHECEL was shown to be superior in terms of product strength, sutureability and seal quality (Fig 4). Indeed, a prospective randomized controlled study (1) found SYNTHECEL to exhibit superior strength and sutureability (Figs 5-6). In terms of surgical handling, SYNTHECEL is similar in thickness to human dura and conforms easily to the brain.

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Fig 4a: Demonstrating the product's strength.
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Fig 4b: Demonstrating the product's sutureability.
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Fig 5 SYNTHECEL Dura Repair exhibited superior device strength compared to a control group, in an assessment of device handling characteristics [1].
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Fig 6 The product also exhibited superior seal quality compared to the control group [1].

References

(1) Rosen, Charles L., et al. Results of the Prospective, Randomized, Multicenter Clinical Trial Evaluating a Biosynthesized Cellulose Graft for Repair of Dural Defects. Neurosurgery. 2011 Nov;69(5):1093-103; discussion 1103-4. (See Supporting Documents)

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