Management of orbital and periorbital arteriovenous malformations.

Arteriovenous malformations (AVMs) of the orbit are progressively enlarging communications between arteries and veins that bypass normal capillary beds. In contrast to arteriovenous fistulas (AVFs), AVMs are congenital 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 managed AVM of the orbit and periorbital tissues in four patients. Neuroimaging studies, clinical decision making, operative experience, and long-term 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 cases over follow up ranging from 2 to 5 years. We conclude that identification of all arterial feeders, from both internal and external carotid 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 appropriately chosen surgical team, most AVMs can and should be treated by a combined approach of preoperative embolization followed by surgical excision of the vascular mass. The goal of therapy is closure of the low-resistance shunt.