MANAGEMENT OF ORBITAL AND PERIORBITAL ARTERIOVENOUS-MALFORMATIONS

Arteriovenous malformations (AVMs) of the orbit are progressively enla rging communications between arteries and veins that bypass normal cap illary beds. In contrast to arteriovenous fistulas (AVFs), AVMs are co ngenital lesions with multiple large feeding arteries, a central nidus , and numerous dilated draining veins. Management of AVMs of the orbit may be difficult due to the threat of hemorrhage, vascular occlusion during treatment, and collateral damage to surrounding organs. We mana ged AVM of the orbit and periorbital tissues in four patients. Neuroim aging studies, clinical decision making, operative experience, and lon gterm postoperative results were retrospectively reviewed. Four cases of AVM of the orbit and periorbital tissues were successfully treated with preoperative embolization and subsequent excision of the central nidus of the AVM. There was no evidence of recurrence in any of the ca ses over follow up ranging from 2 to 5 years. We conclude that identif ication of all arterial feeders, from both internal and external carot id systems, is critical in developing a therapeutic plan. AVMs may be treated by surgical excision alone, or embolization alone. However, in the hands of an experienced interventional neuroradiologist and an ap propriately chosen surgical team, most AVMs can and should be treated by a combined approach of preoperative embolization followed by surgic al excision of the vascular mass. The goal of therapy is closure of th e low-resistance shunt.