Visual loss from arterial steal in patients with maxillofacial arteriovenous malformation

Objective: To determine whether an arterial "steal" from the ophthalmic art ery accounts for the ocular manifestations associated with maxillofacial ar teriovenous malformation (AVM) outside the orbit. Design: Retrospective noncomparative case series. Participants: Seven patients with maxillofacial AVM who had been previously treated, unsuccessfully, with proximal ligation of the supplying external carotid artery branches were evaluated clinically and by superselective cer ebral angiography, No cases had intraorbital arteriovenous shunting or abno rmal venous drainage to the orbit. Intervention: Endovascular embolization. Main Outcome Measures: Signs and symptoms of ocular ischemia were correlate d with findings on cerebral/orbital angiography. Results: Four of seven patients had signs of ocular ischemia, By selective angiography, these four patients were found to have a significant ophthalmi c artery supply to the AVM, In contrast, the three patients without signs o f ocular ischemia had minimal or no ophthalmic artery supply to the AVM. Conclusions: When the ophthalmic arterial blood supply is recruited, ophtha lmic artery "steal" phenomenon occurs in patients with maxillofacial AVMs t hat do not directly involve the orbit, This mechanism appears to be the cau se of ocular ischemia. It is possible that this "steal" is precipitated or worsened by previous surgical proximal ligation of external carotid arteria l branches that are potential collaterals with the ophthalmic artery but fa il to occlude the arteriovenous (AV) shunts. (C) 2000 by the American Acade my of Ophthalmology.