Use of Advanced Intraoperative Navigation for Percutaneous Transorbital Inferior Ophthalmic Vein Access in Embolization of a Residual Type D Carotid-Cavernous Fistula

Carotid-cavernous fistulas (CCFs) are abnormal connections between the carotid artery and the cavernous sinus (CS).¹ While transorbital access via the superior ophthalmic vein (SOV) is well described, percutaneous access via the inferior ophthalmic vein (IOV) is rarely reported.² A 78-year-old woman presented with a 1-year history of left proptosis, pulsatile tinnitus, and more recent visual changes. Digital subtraction angiography revealed a Barrow type D CCF with drainage into the left sylvian vein and IOV. Due to isolated IOV drainage, direct transorbital puncture was performed in a hybrid operating room with the patient's head immobilized in a Mayfield head holder. Brainlab AngioFusion was utilized for preoperative trajectory planning and intraoperative navigation, providing complementary verification of entry point and trajectory, while Siemens Needle Guidance was used for real-time needle localization and alignment. Embolization was completed using coils and Onyx to achieve a complete angiographic cure of the fistula. Postoperatively, the patient reported marked improvement in vision. Indirect CCFs with isolated IOV drainage may necessitate direct transorbital access when conventional routes are not feasible.