Modified lateral orbitotomy approach for resection of anterior temporal cavernous malformation

BACKGROUND: The lateral orbitotomy approach (LOA) provides a direct and minimally invasive corridor to orbital apex, cavernous sinus, and middle cranial fossa (MCF) lesions. Removal of the lateral orbital wall and retraction of the orbital contents, as performed with a traditional LOA, can cause diplopia and enophthalmos and affect visual acuity. The modified LOA (mLOA) preserves the lateral orbital wall to limit this morbidity. CASE DESCRIPTION: A 58-year-old man experienced new-onset headaches and anxiety attacks that improved with anti-seizure medication. He was neurologically intact on examination. Magnetic resonance imaging demonstrated a 2-cm right anterior temporal cavernous malformation with an associated hemosiderin ring. Electroencephalogram revealed right temporal intermittent rhythmic delta activity suspicious for anterior temporal lobe epilepsy. He underwent an endoscopic-assisted keyhole mLOA for resection of the cavernoma and hemosiderin-stained brain. Key steps included a Y-shaped incision in the upper eyelid/lateral canthus, removal of a 1.5-cm segment of the lateral orbital rim, drilling of the lateral orbital wall with preservation of the medial cortex, drilling the lateral sphenoid ridge to access the anterior temporal lobe, resecting the cavernoma with endoscopic assistance for removal of all potentially epileptogenic abnormal brain, and plating the orbital rim as part of a layered closure. Postoperatively, he remained neurologically intact. He was discharged on postoperative day 4 after resolution of a cerebrospinal fluid leak with lumbar drainage. On follow-up, his anxiety attacks had completely resolved, and his incision was well-healed. CONCLUSION: The mLOA is an ideal keyhole technique for selected lesions of the MCF.