A Simple Scoring System to Predict the Resectability of Skull Base Meningiomas via an Endoscopic Endonasal Approach.

Objective: To identify clinico-radiologic factors associated with incomplete anterior cranial fossa (ACF) meningioma resection via an endoscopic endonasal approach.

Methods: Patients undergoing endoscopic endonasal resection of an ACF meningioma were retrospectively accrued from two university-affiliated centers. Demographic profiles and radiologic findings, including tumor dimensions and morphology, anatomic location, and vascular involvement, were stratified according to the extent of resection.

Results: Twenty-five patients were included in this study. Factors associated with incomplete surgical resection via an endonasal route were: presence of hyperostosis (P = 0.04), cavernous internal carotid artery involvement (P = 0.001), maximal dural tail length in the transverse plane (P = 0.006), and its ratio to the inter-fovea ethmoidalis distance (P = 0.01). Using a multiple regression analysis, only cavernous internal carotid artery involvement (P = 0.002) and a large dural tail length to inter-foveal distance ratio (P = 0.04) were significant predictors of incomplete resection (multiple correlation coefficient = 0.71). The combination of predictive factors to determine the likelihood of complete endoscopic resection produced a scoring system with a sensitivity and specificity of 85.7% (95% confidence interval [CI], 42.1-99.6] and 100% (95% CI, 81.5-100), respectively.

Conclusions: The use of a simple scoring system outlined in our study can facilitate proper patient selection for endoscopic endonasal resection of ACF meningiomas.