Vascular malformations of the orbit (lymphatic, venous, arteriovenous): Diagnosis, management and results.

Vascular malformations are often found inside the orbit. Isolated venous malformations (frequently misnamed as cavernous hemangiomas) are the most frequent among these. However, also lymphatic and arteriovenous malformations can affect the orbit. The complex anatomy of the orbit and the fact that its content easily suffers from compartmental syndrome explain why treating orbital vascular malformations can be challenging and technically demanding. In this study, two institutions have retrospectively collected their cases, consisting in a total of 69 vascular malformations of the orbit. Each type of malformation has been evaluated separately in terms of diagnosis, indications for treatment, techniques and outcomes. Moreover, the authors have analyzed in detail venous malformations, identifying three different types, named orbital venous malformation (OVM) 1, 2 and 3. These behave differently from each other, and a prompt differential diagnosis is mandatory to pose correct indications, minimize risks and improve results. Overall, surgery was the technique of choice for OVM1, microcystic lymphatic malformations (LM) and arteriovenous malformations (AVM). A pure transnasal approach with mass removal and reconstruction of the medial wall with polyethylene sheets was chosen for OVM1 (intra- or extraconal) located in the medial or superomedial compartment. Sclerotherapy had a role in treating macrocystic LM and OVM3.