Pedicled extranasal flaps in skull base reconstruction

Cerebrospinal fluid (CSF) leaks most commonly arise during or after skull base surgery, although they occasionally present spontaneously. Recent advances in the repair of CSF leaks have enabled endoscopic endonasal surgery to become the preferred option for management of skull base pathology. Small defects (<1 cm) can be repaired by multilayered free grafts. For large defects (>3 cm), pedicled vascular flaps are the repair method of choice, resulting in much lower rates of postoperative CSF leaks. The pedicled nasoseptal flap (NSF) constitutes the primary reconstructive option for the vast majority of skull base defects. It has a large area of potential coverage and high rates of success. However, preoperative planning is required to avoid sacrificing the NSF during resection. In cases where the NSF is unavailable, often due to tumor involvement of the septum or previous resection removing or compromising the flap, other flaps may be considered. These flaps include intranasal options - inferior turbinate or middle turbinate flaps - as well as regional pedicled flaps: pericranial flap, temporoparietal fascial flap, or palatal flap. More recently, novel alternatives such as the pedicled facial buccinator flap and the pedicled occipital galeopericranial flap have been added to the arsenal of options for skull base reconstruction. Characteristics of and appropriate uses for each flap are described.