Simultaneous Combined Endonasal and Transorbital Endoscopic Approach for a Large Orbital Cavernous Venous Malformation: A Technical Case Report.

Orbital cavernous venous malformation (OCVM) is among the most common benign intraconal orbital lesions. Traditionally, ophthalmologists have treated these lesions through a transorbital approach (TOA), while neurosurgeons have favored transcranial access. More recently, the endoscopic endonasal approach (EEA) has become preferred for lesions located inferomedial to the optic nerve. In selected complex cases of orbital lesions, combined approaches integrating EEA and TOA have been employed to overcome the limitations of each method. We report the case of a woman in her 50s with a prior history of transcranial surgery, who presented with complete vision loss in the right eye and exophthalmos due to a large intraconal OCVM. Through collaboration among neurosurgeons, an otorhinolaryngologist, and an oculoplastic surgeon, a simultaneous combined endoscopic approach was undertaken using the EEA and an endoscope-assisted lateral orbitotomy as TOA. Endoscopes were employed in both surgical corridors, enabling circumferential, 360-degree dissection and en bloc removal. Postoperatively, the patient's right-sided exophthalmos resolved, whereas vision loss remained irreversible. Ptosis, extraocular movement disturbances, and mydriasis developed and gradually improved over time. This case highlights the feasibility of a simultaneous endoscopic EEA and TOA for managing complex intraorbital lesions. Successful execution of such combined approaches requires thorough, meticulous preoperative planning and close multidisciplinary collaboration tailored to each patient.