Many patients have vascular malformations that are made up of different types of abnormally formed vascular channels. One of the most common forms is Klippel-Trenaunay Syndrome also called CLVM because it involves malformations of the capillaries, lymphatics and veins. It usually affects an arm or leg, although the chest wall or abdomen can also be involved. Patients with this condition present in different ways depending upon the type and severity of their anomalies. Treatment often requires input from numerous specialties, including pediatrics, pediatric orthopedics, plastic surgery and endovascular surgery. When symptoms are related to malformations of the veins, endovenous laser and venous embolization or sclerotherapy can be effective.