[Frontal sinus approach to olfactory groove meningiomas]

We report on our experience of the frontal sinus approach for removing olfactory groove meningiomas. Five tumors were operated on, one unilateral, four bilateral. Osteotomy of the anterior wall of the frontal sinus was performed with an oscillating saw without any burr hole. The posterior wall of the sinus was resected and the tumor was attacked along the plane of the anterior skull base. Ethmoidal blood supply was controlled at the initial stage of the operation, allowing avascular tumor debulking. Olfactory nerves, invaded by the tumor, usually cannot be spared. Tumor extensions towards the sella and the optic canals were removed without any brain retraction, nor opening of the sylvian fissure, nor dissection of the carotid arteries. The frontal sinus approach is technically easy to achieve. Osteotomy and reconstruction of the anterior wall of the frontal sinus are rapidly performed. When the frontal sinus is small, image guided surgery allows to delineate precisely its limits and the flap includes the calvarial outer layer, tangenitally cut from one supra-orbital canal to the other. Cosmetic result is perfect. The frontal sinus approach gives access to the medial part of the orbital roofs and to the central anterior skull base from the crista galli to the tuberculum sellae and the anterior clinoids. The frontal sinus approach represents an alternative to conventional craniotomies for tumors developed in the central anterior skull base, especially for olfactory groove meningiomas.