2026 Poster Presentations
P124: SURGICAL OUTCOMES AND COMPLICATION PROFILES FOLLOWING FAR-LATERAL AND EXTREME-LATERAL APPROACHES FOR FORAMEN MAGNUM MENINGIOMAS: A SINGLE-ARM META-ANALYSIS
Khushal Gupta, MBBS1; Michael Karsy, MD, PhD, MSc, FAANS, FCNS2; 1Bharat Ratna Late Shri Atal Bihari Vajpayee Memorial Medical College; 2University of Michigan Health
Background: Foramen magnum meningiomas (FMMs) represent one of the most technically challenging skull base pathologies, given their intimate relationship with the lower cranial nerves, vertebrobasilar system, and cervicomedullary junction. The far-lateral and extreme-lateral approaches were developed to provide safer access to these lesions, yet questions remain regarding the consistency of complete resection, operative risks, and long-term tumor control. We performed a systematic review and single-arm meta-analysis to consolidate current evidence on surgical outcomes with these approaches.
Methods: Following PRISMA guidelines, PubMed, Embase, and Scopus were searched from inception through May 2025. Eligible studies included case series and cohort studies reporting outcomes of ≥5 patients undergoing far-lateral or extreme-lateral resections of FMMs. Case reports and review articles were excluded. Data were extracted into a structured Excel template that captured demographics, surgical details, extent of resection, complications, and follow-up outcomes. Meta-analyses were performed using a DerSimonian–Laird random-effects model with inverse variance weighting and Freeman–Tukey double arcsine transformation to stabilize proportions. Between-study heterogeneity was assessed with the I² statistic, and prediction intervals were calculated to account for uncertainty across future studies.
Results: Six studies comprising a total of 140 patients met inclusion criteria. Across this cohort, the likelihood of achieving gross total resection was high, with a pooled rate of 82% (95% CI: 74–88%). Heterogeneity was negligible (I² = 0%). Perioperative mortality was rare; in five studies encompassing 124 patients, the pooled mortality rate was 1% (95% CI: 0–3%). At a follow-up range of 2–6 years, the pooled recurrence rate was 3% (95% CI: 1–7%), again with no evidence of heterogeneity (I² = 0%). However, data on the use of adjuvant radiotherapy were inconsistently reported, limiting the ability to fully distinguish surgical durability from adjuvant treatment effects.
Conclusion: This meta-analysis highlights that the far-lateral and extreme-lateral approaches to foramen magnum meningiomas provide a balance of surgical radicality and safety. Surgeons achieved high rates of gross total resection while maintaining very low perioperative mortality and durable long-term tumor control. The negligible heterogeneity across studies underscores the reproducibility of these outcomes across centers, and the low mortality supports their safety in modern skull base practice. Data on adjuvant radiotherapy were inconsistently reported, representing a limitation in interpreting long-term tumor control. Future multicenter registries are needed to refine patient selection, evaluate neurological and functional recovery, and optimize surveillance strategies.
