Traumatic Intraorbital Arteriovenous Fistula

Traumatic intraorbital arteriovenous fistulas (AVFs) are extremely rare low flow shunts that bypass the capillary bed and create a connection between the arterial and venous systems which are mainly supplied by the ophthalmic artery then drained by the superior ophthalmic vein (SOV). Intracranial dural AVFs account for 10%–15% of all intracranial arteriovenous malformations, with incidence around 0.15–0.29 per 100,000 persons per year. Clinical symptoms are associated with increased venous pressure inside the orbit, causing proptosis, orbital congestion, increased intraocular pressure and subsequent loss of vision from glaucoma. Asymptomatic lesions are generally treated conservatively, with serial monitoring, however, those that are symptomatic require surgical intervention to prevent devastating complications. The authors wish to present a case of traumatic infraorbital AVFs (IOAVF) treated with direct surgical intervention through the medial transconjunctival approach, which is a method mostly implemented to expose the medial orbital floor for reconstructive procedures, making this case unique. A 54 year old male presented with progressive proptosis, double vision, orbital congestion and decreased visual acuity of the left eye following a penetrating injury of the left orbit with a screwdriver. Digital subtraction angiography (DSA) demonstrated an orbital AVF fed by a dilatated SOV to prominent orbital venous drainage. The patient underwent attempted ultrasound guided percutaneous direct transvenous endovascular embolization of the AVF with complications involving vessel rupture with intraocular bleeding and contrast extravasation, which failed to treat the fistula. Subsequently, the patient underwent surgical litigation of AVF through a medial transconjunctival approach. Results: Follow up DSA revealed complete obliteration of the AVF. Traumatic IOAVF is an extremely rare type of AVF. Treatment of these lesions can be challenging. Surgical intervention with the implementation of medial transconjunctival approach has been found to be safe and effective for patients with traumatic intraorbital AVFs.