Arteriovenous Malformations

Riley-Smith syndrome Macrocephaly, pseudopapilloedema, lymphaticovenous malformation Introduction An arteriovenous malformation (AVM) is defined as an abnormal communication between an artery and vein that bypasses a capillary bed. These lesions may present as isolated, innocuous cutaneous naevi, or they rarely may take the form of life-threatening systemic shunts involving large portions of the body. They may occur at any site, involve any organ, and violate normal tissue planes. AVMs are present at birth, and are neither neoplastic nor proliferative. As such, they grow commensurate with the child. AVMs are best characterised by the type of abnormal vascular channel, the degree of blood flow, and the structures involved. The most common sites of these lesions are the pelvis, extremities, and intracranial circulation.1 Cutaneous AVMs are usually noted at birth but are given little attention due to their innocent appearance. A standard approach to management of AVMs does not exist due to the rare need for treatment. Furthermore, AVMs are frequently associated with additional findings and fall under the auspices of multiple syndromes2 (Table 112.1).