Palatal Flap Modifications Allow Pedicled Reconstruction of the Skull Base

Abstract

Defects after endoscopic expanded endonasal approaches (EEA) to the skull base, have exposed limitations of traditional reconstructive techniques. The ability to adequately reconstruct these defects has lagged behind the ability to approach/resect lesions at the skull base. The posteriorly pedicled nasoseptal flap is our primary reconstructive option; however, prior surgery or tumors can preclude its use. We focused on the branches of the internal maxillary artery, to develop novel pedicled flaps, to facilitate the reconstruction of defects encountered after skull base expanded endonasal approaches. Feasibility. We reviewed radiology images with attention to the pterygopalatine fossa and the descending palatine vessels (DPV), which supply the palate. Using cadaver dissections, we investigated the feasibility of transposing the standard mucoperiosteal palatal flap into the nasal cavity and mobilizing the DPV for pedicled skull base reconstruction. We transposed the palate mucoperiosteum into the nasal cavity through limited enlargement of a single greater palatine foramen. Our method preserves the integrity of the nasal floor mucosa, and mobilizes the DPV from the greater palatine foramen to their origin in the pterygopalatine fossa. Radiological measurements and cadevaric dissections suggest that the transposed, pedicled palatal flap (the Oliver pedicled palatal flap) could be used to reconstruct defects of the planum, sella, and clivus. Our novel modifications to the island palatal flap yield a large (12-18 cm(2)) mucoperiosteal flap based on a approximately 3 cm pedicle. The Oliver pedicled palatal flap shows potential for nasal cavity and skull base reconstruction (see video, available online only).