A case of Delayed Carotid Cavernous Fistula After Facial Gunshot Injury presented as loss of vision with Symptom Resolution After Endovascular Closure Procedure

AbstractCarotid cavernous fistulas are abnormal connections between the carotid artery and the cavernous sinus. Blunt and penetrating head injuries can result in a caroticocavernous fistula. Although its occurrence is rare, the diagnosis can be made in the emergency department. This case demonstrates a 26-year-old man who presented with the complaints of pain, redness, blurred and loss of vision in right eye and swelling of his upper face which had been occurred due to a gunshot injury from his face 35 days ago.

Key words: Carotid cavernous fistula, gunshot injury, endovascular intervention, endovascular treatment.

Introduction: Posttraumatic Carotid Cavernous Fistulas (CCFs) are direct communications between the Internal Carotid Artery (ICA) and the Cavernous Sinus (CS) and are frequently encountered as a complication of closed head trauma although few reports pointed to a penetrating object or gunshot injuries (1). They are usually diagnosed a few weeks after trauma and majority of signs and symptoms result from increased venous pressure in the ophthalmic vein that lacks a valve (2). Although CCFs are not life-threatening, timing of diagnosis is of extremely important since a permanent loss of vision may develop within hours to days after the initial injury. The most common signs and symptoms associated with CCFs are pulsatile exophthalmus, orbital murmur, conjunctival hyposphagma, ophthalmoplegia, orbital pain, and impaired visual acuity (1,3). CT angiography is helpful for diagnosis with pathognomonic radiological signs and might also be used for screening. Exact point of fistula as well as nature of the lesion might be further studied via Digital Subtraction Angiography (DSA) (4). Endovascular embolization is preferred treatment approach within the last two decade and surgical treatment remains a treatment option endovascular treatment fails or is not possible (5,6). This report provides a current discussion about the presentation, pathogenesis, and management of carotid cavernous sinus fistulas.

Key words: Carotid Cavernous Fistula, Gunshot Injury, Endovascular Intervention, EndovascularTreatment.

Case reportA 26-year-old man presented to emergency department with the complaints of pain, redness, blurred and loss of vision in right eye. Initial complaints were mild and first noted 15 days ago before clinical presentation. Past history was unremarkable except a gunshot injury from the face 35 days ago which was managed through conservative measures.On physical examination, general status was normal and a scar tissue was noted over the right nasal sulcus pointing to the entry hole of a bullet. Neurological examination did not reveal any abnormality. Typical murmur was audible at the right orbit suggesting a diagnosis for CCF. Initial radiographic scans revealed a bullet on the right side of face (Figure 1). The patient was referred to ophtalmology and on their examination his corrected visual acuity was 0.3 at the right side and 1.0 on the left. Biomicroscopic evaluation was compatible with eyelid edema, chemosis, proptosis, dilated fixed pupils and negative light reflex in right eye. Fundoscopic examination revealed marked venous congestion and increased tortuosity, arteriolar thinning, and preretinal hemorrhages at the right eye. Intraocular pressure measured through tonometry was 34 mm Hg on the right eye and 16 mm Hg on the left. Color Doppler ultrasonography, orbital tomography with and without contrast on axial plane, Magnetic Resonance Imaging (MRI), Magnetic Resonance Angiography (MRA), and DSA scans confirmed the diagnosis of CCF. The examinations revealed a fistula between the right internal carotid artery and right cavernous sinus (Figure 1a). Endovascular treatment was performed for treatment through femoral artery route under general anesthesia without any complication. Postoperative course was uneventful and typical murmurs disappeared on auscultation of the orbit. Complaints of pain, redness, blurred and loss of vision on the right eye markedly improved within 3 weeks after intervention. Postoperative angiographic scans demonstrated complete obliteration of the fistula (Figure 1b).