Approaches in microsurgery for olfactory meningiomas: a systematic review and meta-analysis

Olfactory meningiomas are common neoplasms accounting for 4.5-18% of all intracranial meningiomas. Currently, transcranial (pterional, unilateral subfrontal, bilateral subfrontal, interhemispheric and through the frontal sinus) and endoscopic endonasal approaches are actively used. OBJECTIVE: To study the efficacy and safety of various surgical approaches to olfactory meningiomas. MATERIAL AND METHODS: The study included reports with data on clinical manifestations, surgical approach, extent of resection and postoperative complications in patients with olfactory meningiomas. Among 7.588 manuscripts, we enrolled 6.912 articles into screening after duplicate removal. There were 471 articles after title evaluation and 30 manuscripts after abstract review. After full-text review, 15 most relevant articles were selected for final analysis. RESULTS: Meta-analysis included 634 patients with olfactory meningiomas. The most common preoperative symptom was olfactory impairment (hyposmia/anosmia) (390 (62%) patients). The least common symptom was visual impairment (260 (41%) patients). Psychoemotional and/or cognitive impairment was observed in 270 (43%) patients. Bilateral subfrontal approach was the most common (226 (36%) cases), while interhemispheric access was the rarest (25 (4%) cases). Pterional approach was used in 100 (16%) cases, supraorbital approach in 95 (15%), endoscopic transnasal approach in 138 (22%) cases, and resection through the frontal sinus in 50 (8%) cases. Tumor resection Simpson I / II was achieved in 513 (81%) cases. CONCLUSION: Surgery is the primary treatment for olfactory meningiomas. Optimal surgical approach should be determined after a comprehensive assessment of several factors, including tumor size and growth direction, clinical manifestations, severity of perifocal edema and individual anatomical features (particularly, dimensions of paranasal sinuses).