Endoscopic reconstruction of frontal, cribiform and ethmoid skull base defects.

Endoscopic skull base reconstruction (ESBR) is an established option for complete reconstruction of the anterior skull base (ASB). While free mucosal grafts are still relevant for limited defects (<10 mm), the evolution of vascular flaps has extended the limits of reconstruction with up to 94% success in defect closure and avoidance of cerebrospinal fluid (CSF) leak. This article discusses the planning and execution in ESBR for anterior fossa defects. Factors influencing the choice of reconstruction (flap location, size, influence of raised intracranial pressure, high flow CSF leak, radiotherapy) are examined. The reconstructive options are discussed, including the nasoseptal flap (NSF), inferior turbinate pedicled flap and the endopericranial flap, with particular emphasis on the technical aspects of reconstruction using the NSF. A step-by-step description, with an accompanying video, is provided. Techniques applicable to ESBR in general (subdural graft placement, graft/flap placement, barrier and support dressing) are covered. Novel flaps for ASB reconstruction are also briefly-described.