Moaath Alghamdi

Background/Objectives: Expanded endoscopic endonasal approaches (EEAs) provide direct ventral access to adult intradural skull base tumors; however, postoperative complications are variably defined and reported in the literature. This review aimed to synthesize the overall spectrum of adult intradural EEA complications and distinguish pathology-specific evidence from large mixed EEA complication cohorts. Methods: A PRISMA 2020 systematic review and meta-analysis searched PubMed/MEDLINE, Embase, and Web of Science from database inception through July 2026. Eligible studies included adults or adult-separable subgroups undergoing expanded EEAs for intradural skull base tumors. The primary outcomes were CSF leak, meningitis or intracranial infection, new neurological deficit or vascular injury/stroke, hydrocephalus, mortality, and postoperative seizures. Pathology-specific adult intradural series with exact counts were quantitatively synthesized when appropriate, and large mixed EEA cohorts were summarized separately when the eligible subgroup was not separable. Results: After full-text eligibility assessment, 48 reports were retained in the extraction-status set. Three strictly adult-only exact-count reports contributed to the primary CSF leak meta-analysis, yielding a random-effects incidence of 23.0% (95% CI, 10.5–43.1%; I² = 78.7%). A sensitivity analysis adding one mixed-age cohort yielded 23.8% (95% CI, 14.5–36.6%; I² = 68.9%), while a broader sensitivity analysis including both mixed-age reports yielded 21.1% (95% CI, 12.2–33.8%; I² = 69.4%). Meningitis was reported in 6/166 patients across four studies (3.6%; 95% exact CI, 1.3–7.7%), and new neurological deficit/vascular injury/stroke was reported in 4/166 patients across four studies (2.4%; 95% exact CI, 0.7–6.1%). Postoperative seizures were reported in 4/652 patients across two studies (0.6%; 95% exact CI, 0.2–1.6%). Large mixed EEA cohorts were summarized separately because adult intradural tumor subsets could not be separated. Conclusions: CSF leak was the most consistently reported complication after expanded EEAs for adult intradural skull base tumors. The strict adult-only random-effects estimate was 23.0%, but it was based on only three studies and showed substantial heterogeneity, limiting its generalizability. Meningitis, neurological/vascular events, and seizures were uncommon in the extractable data and were summarized descriptively rather than being meta-analyzed. Large mixed EEA cohorts provide important safety context but cannot substitute for standardized adult intradural, pathology-specific reporting.

Background/Objectives: Expanded endoscopic endonasal approaches (EEA) provide direct ventral access to adult intradural skull base tumors; however, postoperative complications are variably defined and reported in the literature. This review aimed to synthesize the overall spectrum of adult intradural EEA complications and distinguish pathology-specific evidence from large mixed EEA complication cohorts. Methods: A PRISMA 2020 systematic review and meta-analysis searched PubMed/MEDLINE, Embase, and Web of Science from database inception through July 2026. Eligible studies included adults or adult-separable subgroups undergoing expanded EEA for intradural skull base tumors. The primary outcomes were CSF leak, meningitis or intracranial infection, new neurological deficit or vascular injury/stroke, hydrocephalus, mortality, and postoperative seizures. Pathology-specific adult intradural series with exact counts were quantitatively synthesized when appropriate, and large mixed EEA cohorts were summarized separately when the eligible subgroup was not separable. Results: The full-text screening set included 48 reports. Five exact-count reports, including one mixed-age contextual report, contributed to the CSF leak meta-analysis and yielded a random-effects incidence of 21.1% (95% CI, 12.2%-33.8%; I² = 69.4%). Excluding the mixed-age reports yielded 23.8% (95% CI, 14.5%-36.6%). Meningitis was reported in 6/166 patients (3.6%; 95% exact CI, 1.3%-7.7%), and new neurological deficit/vascular injury/stroke in 4/166 (2.4%; 95% exact CI, 0.7%-6.1%); these rare outcomes were summarized descriptively without continuity correction. Postoperative seizures were reported in 4/652 patients (0.6%) in two studies. Large mixed EEA cohorts have reported CSF leak rates of 1.6%-15.9% but these were not pooled because adult intradural tumor subsets were not separable. Conclusion: CSF leak was the most consistently reported complication after expanded EEA for adult intradural skull base tumors; however, its incidence varied substantially across pathologies and centers. Meningitis, neurological/vascular events, and seizures were uncommon in the extractable data and were better interpreted descriptively than as precise pooled rates. Large mixed EEA cohorts provide important safety context but cannot substitute standardized adult intradural, pathology-specific reporting.