Basilar artery entrapment in a clival fracture presenting with hemorrhage: First successful endoscopic endonasal wrapping

Background: Basilar artery incarceration within a clival fracture is a rare traumatic condition. The herniated arterial segment, typically located deep within the sphenoid sinus and wedged between the fracture fragments, poses diagnostic and therapeutic challenges. Although radiological findings have been described, direct endoscopic endonasal visualization of an incarcerated basilar artery has not been previously reported. Safe management remains difficult due to anatomical inaccessibility through traditional transcranial routes and the risks associated with endovascular treatment. Case Description: A 51-year-old man presented with massive epistaxis and subarachnoid hemorrhage after a fall approximately 1.5 m. Imaging revealed basilar artery incarceration and herniation of the sphenoid sinus through a longitudinal clival fracture. During conservative management, the patient developed brainstem and bilateral superior cerebellar artery infarctions. Angiography demonstrated progressive recanalization, raising concerns regarding aneurysmal evolution and rebleeding. Because transcranial and endovascular approaches were considered unsafe due to vessel kinking and adjacent perforators, an endoscopic endonasal transsphenoidal approach was selected. On day 21, the incarcerated and dissected arterial segments were directly visualized and successfully treated by wrapping with a polyglycolic acid nonwoven fabric. Conclusion: To our knowledge this is the first documented case of direct endoscopic endonasal visualization and treatment of a basilar artery incarcerated within a clival fracture. This case demonstrates that an endoscopic endonasal approach can provide safe and direct access to this lesion and may be an effective therapeutic option in selected patients.