Sphenoid Sinus Pseudoaneurysm With Carotid Cavernous Fistula Presenting With Delayed Subarachnoid Hemorrhage A Case Report

Rationale: Sphenoid sinus pseudoaneurysm arising from the cavernous segment of the internal carotid artery (ICA) caused by traumatic vessel injury is rare, and rarer is a concomitant carotid-cavernous fistula (CCF). In particular, delayed subarachnoid hemorrhage (SAH) due to pseudoaneurysm rupture has not been reported to-date in literature. Here, we report a case of sphenoid sinus pseudoaneurysm with CCF presenting with delayed SAH. Patient concerns: A 73-year-old man presented with traumatic brain injury due to motorcycle accident. Diagnoses: Twenty-four days after admission, the patient's neurological status suddenly deteriorated. Brain computed tomography (CT) showed acute SAH along interhemispheric cisterns and suprasellar intracerebral hematoma. Brain CT angiography and digital subtraction angiography revealed giant sphenoid sinus pseudoaneurysm with CCF and the daughter sac of the pseudoaneurysm extended to the intracranial part via fracture in the superior wall of the sphenoid sinus. Interventions: As the sphenoid sinus pseudoaneurysm and CCF shared one rupture point, endovascular treatment with intraarterial approach using coil and liquid embolic material by balloon assisted technique was performed simultaneously. Outcomes: The origin of the pseudoaneurysmal sac and CCF was sufficiently blocked after injection of liquid embolic material and the lesions completely resolved immediately after endovascular treatment. Lessons: Sphenoid sinus pseudoaneurysm and CCF rarely occur following head trauma through a series of processes involving fracture of the lateral wall of the sphenoid sinus and ICA cavernous segment injury. Sphenoid sinus pseudoaneurysm may present as SAH through intracranial rupture with concomitant superior wall fracture of the sphenoid sinus. Therefore, early diagnosis using CT or magnetic resonance angiography and appropriate treatment through understanding the disease mechanism is necessary.