795 Trends in Cerebrospinal Fluid Leak Rates Following the Extended Endoscopic Endonasal Approach for Anterior Skull Base Meningioma: A Meta-Analysis Over the Last 20 Years

Abstract Introduction The extended endoscopic approach (EEA) provides direct access for resection of tuberculum sellae (TSM) and olfactory groove meningiomas (OGM) but is associated with cerebrospinal fluid (CSF) leak in up to 25% patients. To evaluate the impact improved skull base reconstructive techniques, we assessed published CSF percentages EEA over last two decades. Method Random-effects meta-analyses were performed studies between 2004-2020. Outcomes leak, gross total resection, visual improvement, intraoperative arterial injury 30-day mortality. For main analyses, publications pragmatically grouped based on publication year three categories: 2004-2010, 2011-2015, 2016-2020. Results We included 29 describing 540 TSM 115 OGM incidence dropped time from 22% (95% CI: 6-43%) 2004 2010, 16% 11-23%) 2011 2015, 4% 1-9%) 2016 2020. injury, mortality remained stable Conclusions report a noticeable decrease time, which might be attributed development techniques (e.g., hadad bassagasteguy flap, gasket seal), refined multilayer repair protocols, selected lumbar drain usage.