Endoscopic occipital interhemispheric contralateral approach for middle-third falcine meningiomas: A venous-sparing...

Middle-third falcine meningiomas are challenging because direct ipsilateral interhemispheric corridors often conflict with dense parasagittal bridging veins. We developed the endoscopic occipital interhemispheric contralateral approach (EOICA) as a gravity-assisted, retractorless, venous-sparing strategy for selected middle-third falcine meningiomas without superior sagittal sinus invasion. We retrospectively reviewed consecutive adults who underwent EOICA at the study institution between July 2020 and July 2024. Extent of resection was assessed on 3-month contrast-enhanced magnetic resonance imaging. Early postoperative computed tomography and magnetic resonance imaging, including diffusion-weighted imaging with apparent diffusion coefficient maps, were reviewed for corridor-related injury, and 30-day complications were graded using the Landriel Ibañez classification. Six patients (4 women; mean age, 57.5 years) underwent EOICA. Mean maximal tumor diameter was 4.3 cm and mean tumor volume was 25.6 cm³. EOICA was completed in all cases without conversion. Gross-total resection was achieved in all patients (Simpson grade I, n = 2; grade II, n = 4). No fixed retractors were used in any patient, and one bridging vein encountered at the craniotomy margin was preserved without sacrifice. Early imaging showed no corridor-related diffusion restriction, occipital contusion, or hemorrhage. Three patients had transient grade I medical events that resolved before discharge, and formal perimetry was normal in all patients. As of the follow-up cutoff in December 2025, the median radiographic follow-up was 29 months (range, 16-62 months), and no patient had radiographic recurrence. EOICA was feasible in this consecutive series, but long-term oncologic control requires larger comparative studies with longer follow-up.