Endoscopic Transnasal Coagulation of Anterior and Posterior Ethmoidal Arteries before Open Resection of Large Anterior Skull Base Meningiomas: A Novel Combined Approach and Review of Two Illustrative Cases

Abstract

Introduction: Large anterior skull base (ASB) meningiomas are occasionally highly vascular, and are supplied predominantly by the anterior and posterior ethmoidal arteries which are branches of the ophthalmic artery. Effective preoperative embolization of these lesions is thwarted by concerns of retrograde embolization of the ophthalmic artery with visual loss or blindness. The standard goal of early intraoperative devascularization of these meningiomas at the basal dural attachment is often difficult until there has been substantial tumor decompression. As such, resection of these lesions is often coupled with lengthy operative times and significant blood loss. Endoscopic transnasal approaches provide direct access to the ethmoidal arteries, and ASB meningiomas are largely devascularized early on in the course of surgical resection. However, endoscopic resection of larger ASB meningiomas has been associated with lengthy resection times, subtotal resection, and increased rate of postoperative CSF leak. In an effort to decrease operative time and blood loss we have adopted a surgical strategy that incorporates endoscopic transnasal devascularization of the tumor as a means to complement the strengths of an open surgical approach. We present our institutional experience with two cases in which we treated large (>4 cm) ASB meningiomas with a combined approach—endoscopic transnasal sacrifice of the anterior and posterior ethmoidal arteries followed by open subfrontal resection.