Post-traumatic Carotid-Cavernous Fistula Following Penetrating Orbital Injury: A Case Report and Literature Review.

Posttraumatic carotid-cavernous fistulas (CCFs) are rare but potentially sight-threatening vascular lesions, most commonly associated with high-energy craniofacial trauma. Direct high-flow CCFs following penetrating orbital injury are exceptionally uncommon and may present with delayed or misleading clinical features. This report describes the case of a 35-year-old homeless man who presented with a two-month history of progressive left orbital symptoms after a knife-inflicted injury. Initial treatment targeted a presumed infectious process; however, persistent proptosis, ocular pain, mydriasis, complete visual loss, and ophthalmoplegia prompted further evaluation. CT angiography, performed due to a contraindication to MRI, demonstrated a direct high-flow left CCF with marked dilation of the cavernous sinus and superior ophthalmic vein. Digital subtraction angiography confirmed a Barrow type A CCF. The patient underwent staged endovascular therapy. Initial transarterial coil embolization achieved approximately 80% occlusion, with partial improvement in proptosis but persistent visual impairment. Follow-up angiography revealed residual shunting, leading to a second-stage covered stent angioplasty. Despite this, residual flow persisted, and a third endovascular procedure was planned. The third-stage intervention was canceled because of inadequate social support, and the patient was discharged prematurely and lost to follow-up. CCFs are rare entities but should be strongly suspected in cases of penetrating ocular trauma associated with proptosis, chemosis, and orbital bruits. One of the most important determinants of visual prognosis is timely diagnosis and prompt management of these lesions. In the present case, the patient's social vulnerability contributed to delayed recognition and treatment, resulting in complete loss of vision. Furthermore, the patient's social circumstances directly limited completion of the planned therapeutic strategy. Thus, social vulnerability emerged as a key determinant of prognosis, influencing both clinical outcomes and access to definitive care.