Endoscopic Removal of a Retained Bullet from the Planum Sphenoidale

A retained bullet within the sphenoid sinus is an unusual entity as it is unlikely for an individual to survive the initial traumatic event. To this point, there are several critical structures that a bullet must pass through or narrowly avoid to reach this location. Furthermore, attempted removal of a foreign body from this site requires meticulous avoidance of several vital structures. We present the case of a 40-year-old male with a remote (25 years prior) history of a gunshot wound to the head and subsequent repair of cerebrospinal fluid leak who presented with persistent headaches, clear rhinorrhea, as well as several emergency room visits for suspected meningitis during the past year. CT imaging demonstrated an apparent retained metallic fragment within the roof of the left sphenoid sinus. MRI revealed a complex fluid collection within the sphenoid sinus, a portion of which was isointense to cerebrospinal fluid. A navigation-guided endoscopic approach was used to remove a bullet from the planum sphenoidale, evacuate a mucopyocele of the sphenoid sinus, and reduce a meningocele adjacent to the orbital apex. Subsequently, a multilayered closure consisting of a collagen matrix graft, calcium phosphate cement, fibrin sealant, and nasoseptal flap was used to repair the dural defect. This case calls attention to this rare finding as well as the important considerations related to operative intervention.