Selective Microsurgical Disconnection of Greater Sphenoid Wing Dural Arteriovenous Fistula Through the Subtemporal Approach Under Exoscope Magnification

Objective: Sphenoid dural arteriovenous fistulas located on the greater sphenoid wing carry a notable risk of intracranial hemorrhage due to the frequent presence of cortical venous reflux. Because of the challenging embolization procedure, microsurgery remains a valuable option in these cases. Methods: In most cases, the fistula is located in the anterolateral endocranial surface of the middle cranial fossa just below the sphenoid ridge; however, in a small subset of cases, the fistula is positioned posteriorly and medially in the region between the foramen ovale and rotundum. The former region can be reached using various frontolateral approaches, whereas the latter region can be accessed through a subtemporal trajectory, minimizing temporal lobe retraction. The exoscope has been gaining popularity for improved magnification, visualization, and surgeon ergonomics expanding the surgeon's possible trajectory in skull base surgery. Results: We present a targeted subtemporal approach using the exoscope for selective occlusion of an unruptured greater sphenoid wing dural arteriovenous fistula. With proper brain relaxation, a small temporobasal craniotomy opens a direct corridor to the middle cranial fossa. Exoscope-assisted surgery could improve dissection of the middle cranial base and dynamic temporal lobe retraction and expand the range of anteromedial subtemporal trajectories, providing angles that may be challenging to achieve using the operative microscope, as well as improve the surgeon's ergonomic position. Conclusions: An exoscopic-assisted subtemporal approach is a feasible, safe, and minimally invasive approach to treat unruptured greater sphenoid wing dural arteriovenous fistulas and could be considered an alternative to endovascular treatment.