Anatomy of the superior ophthalmic vein approach for direct endovascular access to vascular lesions of the orbit and cavernous sinus.

Objective: The superior ophthalmic vein (SOV) provides an alternative venous access for the treatment of carotid-cavernous fistulae. Its direct surgical exposure and cannulation can be difficult. This study was performed to identify anatomic landmarks to facilitate localization and exposure of the SOV.

Methods: The vascular tree of 6 formalin-fixed human cadaveric heads was injected with colored silicone. The SOV was exposed using a periorbital incision. The diameter of the SOV, its distance to the inferior border of the incision, and the angle formed by the SOV and sagittal midpupillary line were measured. The tributaries of the SOV and its orbital anatomy and relationship to the supraorbital notch/foramen were evaluated.

Results: The SOV was located in the superomedial quadrant of the orbit. Its mean diameter was 2.2 mm (standard deviation, +/-1.2 mm). The mean distance from the SOV to the superior sulcus of the eyelid nasally was 5.9 mm (standard deviation, +/-2.0 mm). The mean angle formed by the SOV and the sagittal midpupillary line was 27.9 degrees (standard deviation, +/-5.4 degrees). The tributaries of the SOV were the angular vein and supraorbital vein (SPOV). The SPOV, identified in all 12 dissections, could be followed to the SOV within the orbit. The SPOV was always located inside the supraorbital notch/foramen when the latter was present.

Conclusion: The SOV is located at the superomedial quadrant of the orbit. The SPOV is a reliable reference during surgical exposure. A lid crease or subbrow incision centered over the supraorbital notch simplifies identification of the SOV.