A "Mismatched" connection: a rare case of indirect or dural carotid-cavernous fistula: a case based review.

Introduction and importance: A carotid-cavernous sinus fistula is an abnormal connection between the internal or external carotid artery and the venous system of the cavernous sinus. It represents a rare entity, and it is often misdiagnosed due to its overlapping symptoms with other conditions such as cavernous sinus thrombosis or orbital inflammation. Cerebral angiography continues to be the gold standard for diagnosis and surgical planning in patients with CCF, and the endovascular trans-venous approach still represents the primary line of treatment. Trans-arterial technique has become an excellent treatment option since the advent of embolic agents. Case presentation: Here, the authors report the case of a 42-year-old male with a one-week history of impaired visual acuity, bilateral eye edema, eye redness, and ophthalmoplegia. A neuro-ophthalmological examination found proptosis, conjunctival chemosis, and sclera injection. Examination using MR venography and digital subtraction angiography (DSA) revealed an abnormal connection between the meningeal branch of the ICA, the ECA, and the cavernous sinus. The patient received endovascular treatment with Onyx injection into the facial vein with thrombosis of the anterior cavernous sinus. The patient presented an uneventful postoperative period and was symptoms-free on postoperative day 1. Clinical discussion: CCF are rare and challenging conditions that require a multidisciplinary approach. Conclusion: The endovascular treatment represents the gold standard and usually allows an effective interruption of the abnormal vascular connection with an almost immediate resolution of the preoperative signs and symptoms.