Spontaneous Indirect Carotid–Cavernous Fistula In An Elderly Woman: Diagnostic Challenges And Endovascular Management

To report a rare case of spontaneous indirect carotid–cavernous fistula in an elderly woman, highlighting diagnostic challenges and the effectiveness of transvenous endovascular management.

Department of Ophthalmology in collaboration with Interventional Neuroradiology, tertiary referral center.

Observational case report of a 77-year-old woman presenting with painful unilateral red eye and severe headaches. Complete ophthalmological examination was performed, including visual acuity assessment, ocular motility evaluation, slit-lamp examination, intraocular pressure measurement, and fundus examination. Brain MRI with angiographic sequences was conducted, followed by digital subtraction angiography (DSA) for definitive diagnosis. The patient underwent transvenous endovascular embolization using detachable coils.

Clinical examination revealed severe visual acuity reduction (<1/10), ptosis, sixth cranial nerve palsy, episcleral vessel dilation, and a poorly reactive mid-dilated pupil. MRI demonstrated cavernous sinus enlargement with arterialization and dilation of the superior ophthalmic vein. DSA confirmed a low-flow dural carotid–cavernous fistula supplied by meningeal branches of the internal carotid artery. Transvenous embolization was successfully performed. Postoperative evolution was favorable, with resolution of ocular congestion and progressive recovery of ocular motility. Visual acuity improved to 5/10 at three months, with no recurrence at six months.

Spontaneous indirect carotid–cavernous fistula should be suspected in elderly patients presenting with atypical red eye and cranial nerve palsy. Early recognition and confirmation by digital subtraction angiography are essential to avoid delayed diagnosis. Transvenous endovascular embolization is a safe and effective treatment, leading to favorable anatomical and functional outcomes.