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Carotid-cavernous fistula

Last updated: December 3, 2019

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A carotid-cavernous fistula is an abnormal communication between a carotid artery and the cavernous sinus. It is most commonly caused by trauma. The fistula leads to a high-pressure inflow of arterial blood into the venous sinuses, resulting in compression and damage to adjacent structures. The main symptom is diplopia, caused by compression injury of the oculomotor nerves. Other common symptoms include pulsatile tinnitus, exophthalmos, and headache. Diagnosis is established based on typical findings on CT/MRI or angiography (e.g., enlarged cavernous sinus). The preferred treatment method is endovascular occlusion of the fistula with balloons or coils.



  • Arteriovenous fistula formation → high-pressure inflow of arterial blood into venous system → venous congestion

Onset of symptoms may be abrupt or gradual, depending on whether the fistula is direct or indirect:

If not treated swiftly, carotid-cavernous fistulas may result in cerebral hemorrhage/infarction, intracranial hypertension, vision loss, or death!


Initial studies help confirm the diagnosis.


  • Embolization using balloons or coils
    • Direct fistulas: transarterial approach
    • Indirect fistulas: transvenous approach
  • Neurosurgery
    • Indicated if endovascular interventions fail or are not possible
    • Occlusion of the fistula via suturing or packing


  1. Scott IU. Carotid Cavernous Fistula. Carotid Cavernous Fistula. New York, NY: WebMD. Updated: October 14, 2015. Accessed: April 2, 2017.
  2. Bennett JL, Durairaj V, Gonzalez MO. Carotid-cavernous fistulas. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. updated: December 13, 2013. Accessed: April 2, 2017.
  3. Caroticocavernous fistula. Updated: April 2, 2017. Accessed: April 2, 2017.
  4. Seeger JF, Gabrielsen TO, Giannotta SL, Lotz PR. Carotid-Cavernous Sinus Fistulas and Venous Thrombosis. AJNR Am J Neuroradiol. 1980; 1 : p.141-148.
  5. Halbach VV, Hieshima GB, Higashida RT, Reicher M. Carotid cavernous fistulae: indications for urgent treatment. AJR Am J Roentgenol. 1987; 149 (3): p.587-593. doi: 10.2214/ajr.149.3.587 . | Open in Read by QxMD