Cranial Base Repair with Combined Vascularized Nasal Septal Flap and Autologous Tissue Graft Following Expanded Endonasal Endoscopic Neurosurgery

Abstract

The expanded endonasal endoscopic approach provides excellent visualization and access to midline skull base lesions, albeit with a relatively high risk of postoperative cerebrospinal fluid (CSF) leakage. We present our experience with the expanded endonasal endoscopic approach to the skull base in an institution where, previously, a traditional transsphenoidal approach with a surgical microscope had been used. We performed a retrospective review to identify patients who underwent expanded endonasal endoscopic surgery and analyzed demographic, pathological, and operative data with particular attention to repair of the skull base defects in 55 procedures performed on 49 patients. We compared the outcomes of 10 primary operations in which we repaired skull base defects using only autologous or allogeneic tissue grafts and 39 primary operations in which we used a vascularized mucoperichondrial nasal septal flap with or without a layered autologous tissue graft. Primary expanded endonasal endoscopic procedures were performed in 49 patients with sellar pathology (33 pituitary adenomas, 4 Rathke's cleft cysts, 1 pituicytoma, 1 pituitary metastasis) and non-sellar pathology (3 meningiomas, 3 clival chordomas, 1 clival mucocele, 1 craniopharyngioma, and 2 esthesioneuroblastomas). Postoperative CSF leakage occurred following 5 of the 49 primary operations (10.2%). This occurred in 2 of 10 primary operations (20.0%) in which the skull base defect was repaired using only autologous and/or allogeneic tissue grafts, necessitating a total of 3 operative CSF leak repairs in those 2 patients. The remaining 3 postoperative CSF leaks occurred in the 39 primary operations (7.7%) in which skull base repair was performed using a mucoperichondrial nasal septal flap, necessitating operative repair in 2 of those patients. The repair of skull base defects created during expanded endonasal endoscopic surgery is improved by use of a mucoperichondrial nasal septal flap combined with a layered autologous tissue graft. When CSF leakage occurs despite nasal septal flap closure, the site of the leakage may be easier to localize and repair.