Endoscopic Marsupialization and Drainage of a Septated Sphenoid Sinus Mucocele in a Revision Skull Base Setting

Sphenoid sinus mucoceles are rare lesions that account for less than 2% of all sinonasal mucoceles. In revision cases, surgery is more challenging because prior operations alter the normal anatomy and remove important surgical landmarks. A 79-year-old male presented with a headache 10 years after prior sphenoid surgery for fungal disease. Preoperative MRI showed a multiloculated, expansile sphenoid mucocele. Bony erosion involved the sellar floor and the right internal carotid artery (ICA) canal, with additional erosion of the mid-clivus. Endoscopic transnasal marsupialization was performed using the posterior choana and nasal septum as fixed landmarks to localize the sphenoid face. After entering the sphenoid sinus, the optic nerve prominence, ICA prominence, opticocarotid recess, and sella were identified on the posterior wall. A stepwise compartment-by-compartment approach was used to drain the mucocele and remove all septations under continuous visualization of these landmarks. The anterior sphenoid wall was completely removed to establish wide and durable drainage. All mucocele compartments were successfully drained. All posterior sphenoid landmarks were clearly identified. Bony dehiscence was noted at the sellar floor, mid-clivus, and right ICA canal. The dura was intact at all sites. No complications occurred. The headache improved after surgery. Follow-up confirmed a patent sphenoidotomy with no recurrence. This technique provides a safe and systematic approach to revision sphenoid mucocele surgery. It may be applied to other complex sphenoid lesions in which altered anatomy and skull-base dehiscence require careful landmark-based dissection.