Noninvasive hemodynamic classification of carotid-cavernous sinus fistulas by duplex carotid sonography

The hemodynamic classification of the CCF has important implications for prognosis and therapy, but satisfactory criteria for such a differentiation are still lacking. We studied the application of extracranial duplex sonography in 14 cases of CCF with emphasis on the hemodynamic parameters of the RI and flow volume and made a correlation with the angiographic findings. We conclude with proposed duplex sonographic criteria for hemodynamic classification: (1) small RI with increased flow volume in the ICA: direct ICA-cavernous sinus fistulas (type A); (2) normal RI and flow volume in the ICA and ECA: dural branch of ICA-cavernous sinus fistulas (type B); (3) small RI with or without increased flow volume in the ECA: dural branch of ECA-cavernous sinus fistulas (type C) or dural branches of ICA- and ECA-cavernous sinus fistulas (type D). Application for assessment of the therapeutic effectiveness was also demonstrated.