The Superior Ophthalmic Vein: Anatomical Perspective for Transvenous Access to the Cavernous Sinus

The anatomical characteristics of the superior ophthalmic vein (SOV), which is crucial when performing craniofacial surgeries and transvenous access to the cavernous sinus, have not been documented. The present study aimed to explore them using magnetic resonance angiography (MRA). A volumetric, phase-contrast MRA was performed in 74 outpatients not bearing vascular or tumorous pathologies in the face, orbit, and cavernous sinus. The entire course of the SOV was delineated in 46 patients (62%), for 76% on the right side and 83% on the left. These SOVs consistently showed a characteristic morphology with a laterally coursing proximal segment and a medially coursing distal segment. The latter segment was connected to the angular, supraorbital, supratrochlear, facial, and external nasal veins that were inconsistently delineated. The angular vein was tortuous in 51% of the patients on the right and 53% on the left. The morphology of the proximal part of the SOV was also variable and involved a tortuous segment in 11% of the patients on the right and in 7% on the left. Furthermore, in 4 patients (8.7%), a fenestration was found in the right SOVs. Inconsistent tributaries of the SOV, tortuous angular vein, and possible tortuous segment and fenestration of the SOV can make orbital transvenous access to the cavernous sinus difficult.