The implication of trauma-related sphenoid sinus abnormality on direct-type carotid-cavernous fistula

We observe the high association between the trauma-related sphenoid sinus fracture and carotid-cavernous fistula (CCF) at our daily work. Our hypothesis is that the sphenoid sinus fracture warrants the pursuit of cerebral angiography study due to the significant likelihood of internal carotid artery (ICA) injury. In the recent three years, 17 cases of the direct-type CCF are enrolled for analyzing their initial CT findings. All CCF cases were proven by the subsequent catheter angiography studies. Three patterns of imaging findings with regard to the sphenoid sinus are classified: 1) fracture of sphenoid sinus wall with intrasinus hematoma collection, 2) intrasinus hematoma collection without fracture line, 3) unremarkable finding. We determine the individual percentage, disclosing the direct-type CCF is significantly higher in the patients in whom the fracture lines can be identified on routine CT study than those in other two subgroups. Our conclusion is that the CT finding of sphenoid sinus fracture is considered as a useful predictor for possible grave vascular injury. Intactness of bony integrity, no matter with or without hematoma collection is otherwise less possible coinciding with overt ICA injury. Instead, in the latter two conditions, the neighboring carotid canal is another critical site to be scrutinized.