Definition:

Arteriovenous malformation (AVM) is a congenital vascular malformation with direct communication from arteries to veins (arteriovenous shunting) and lack of a normal capillary network. The behavior of peripheral (extracranial) AVM is locally aggressive. AVMs are high-flow vascular malformations, and have a wide range of clinical presentations. Some patients may present with an asymptomatic birthmark, while in some patients, the condition may be even life-threatening, leading to congestive heart failure. Typically during puberty or adolescence, the initially quiescent lesion progresses to an expansive mass with cosmetic and functional disturbance. With later progression, the AVM destroys normal tissues and eventually leads to complications such as severe disfigurement, uncontrollable bleeding, ulceration, pain, and cardiac volume overload. A surgical approach is indicated in well-circumscribed malformations of small size. However, the surgical treatment of larger lesions can often lead to excessive blood loss, in addition to serious complications. Ligation or embolization of the arteries supplying the AVM is usually followed by recurrence.