Diagnosis of traumatic carotid-cavernous sinus fistula by monitoring venous oxygen saturation in the jugular bulb: report of two cases

OBJECTIVE AND IMPORTANCE: A traumatic carotid-cavernous sinus fistula (CCF) is rarely diagnosed early and may sometimes be missed until clinical signs and symptoms appear. The continuous monitoring of cerebral venous oxygen saturation may reveal the presence of a CCF by means of a fiberoptic catheter that records very high oxygen saturation values when positioned in the jugular bulb. CLINICAL PRESENTATION: We report two cases of early diagnosis of CCFs unexpectedly revealed by monitoring the jugular bulb for venous oxygen saturation values that approximated arterial saturation values. One case was diagnosed on Day 3 after admission, and the other was diagnosed shortly after cannulation of the ipsilateral jugular bulb. INTERVENTION: Confirmation of the diagnosis of CCF was obtained by angiography. Intravascular treatment was performed in one case. CONCLUSION: These cases add another diagnostic role to cerebral venous oxygen saturation monitoring. When high cerebral venous oxygen saturation values rapidly or abruptly reach arterial oxygen saturation, the presence of a CCF must be considered and confirmed by arterial angiography.