Endoscopic Transcaruncular Approach for Early Anterior Ethmoidal Artery Cauterization in Large Olfactory Groove Meningioma Surgery: Intraoperative Video.

Large olfactory groove meningiomas (OGMs) derive their primary blood supply from the anterior and posterior ethmoidal arteries (AEA/PEA), which are inaccessible early during conventional subfrontal craniotomy, resulting in massive intraoperative hemorrhage. A 61-year-old man presented with altered consciousness and incoherent speech, which revealed a giant anterior skull-base meningioma with bilateral optic nerve encasement and ethmoid sinus invasion, with digital subtraction angiography confirming bilateral AEA/PEA as the dominant feeder. We used a staged hybrid strategy in which bilateral AEA cauterization through an endoscopic transcaruncular approach was performed before bifrontal craniotomy. This staged devascularization markedly reduced intraoperative hemorrhage and facilitated near-total resection. Histopathology confirmed an atypical meningioma, and 2-year follow-up MRI revealed no recurrence. Single-staged hybrid surgery incorporating endoscopic transcaruncular AEA cauterization is a safe and minimally invasive adjunct for large OGM surgery.