PRECLUDE® Dura Substitute is indicated for use as a temporary or permanent prosthesis for repair of dura mater during neurosurgery. It is contraindicated for cardiovascular defects. Description The Second Generation PRECLUDE® Dura Substitute combines the proven performance of inert expanded polytetrafluoroethylene (ePTFE) with a comparably inert elastomeric fluoropolymer in a three-layer construct. The outer ePTFE layers have a node and fibril microstructure with an average porosity of less than one micron. This porosity provides excellent conformability and handling while minimizing fibrous tissue ingrowth. The elastomeric layer facilitates a watertight seal at the suture line. Supplied as a 0.3 mm thick membrane, PRECLUDE® Dura Substitute serves as a watertight, full thickness dural graft which minimizes tissue attachment between the neural structures and other tissues.