The term Klippel-Trenaunay Syndrome (KTS) describes a combined slow flow vascular malformation, usually composed of a combination of capillary malformation or port wine stain, lymphatic malformation and venous anomalies (capillary lymphaticovenous malformation or CLVM) with overgrowth of the effected limb. Most commonly, KTS involves one or both of the legs, but it can involve the arms or trunk and in rare cases, can involve multiple limbs. Rarely, the individual can also have a port wine stain involving the face. Vascular anomalies that are often misdiagnosed as KTS include capillary or capillary-venous malformation with overgrowth, diffuse venous malformation and Parkes Weber syndrome.

The severity of the vascular malformation in patients with Klippel-Trenaunay Syndrome is extremely variable. Mildly affected individuals can have a port wine stain, a few vesicles, and varicose superficial veins, with some increased length of the effected limb. Severely affected individuals can have massive enlargement of the limb due to extensive lymphatic malformation, and general overgrowth and other congenital abnormalities of the toes of the other foot. Anomalies of the deep veins are often present. Typically, patients with KTS have persistence of embryonic veins (veins that are present in the fetus but usually regress before birth) in the outside of the affected calf and thigh. The enlarged limb is not hot or pulsatile. Cardiac failure is not a problem. Symptoms depend on the type of vascular malformation that is predominant. Patients with minimal swelling and mild varicose veins can have a sensation of heaviness associated with the veins. If the leg is much longer than the normal one, walking and posture can be affected. Patients with extensive lymphatic malformation have severe swelling, may encounter repeated infections and may be unable to wear normal footwear. Patients with severe abnormalities of the veins can form blood clots that can pass into the circulation causing obstruction of the arteries of the lungs (pulmonary embolism).

Patients with Klippel-Trenaunay Syndrome should be evaluated at a Vascular Anomaly center. If there is swelling of the limb, MRI and MR venography are done to determine the type and severity of the vascular malformation. Children should be seen by a pediatric orthopedic surgeon, to be assessed for a difference in the length of the legs and other orthopedic problems. If the veins are malformed, duplex ultrasonography, plethysmography and venography may be necessary to determine whether or not they can be treated.

Basic treatment for Klippel-Trenaunay Syndrome involves the use of graded elastic compression stockings to control swelling by compressing the veins and any lymphatic malformation, and orthopedic management of the leg length discrepancy. Swimming is an excellent activity to maintain fitness. Additional treatment may be needed, depending upon the type and severity of the vascular malformations, and is determined for each individual. Procedures include:

• Surgical debulking to remove excessive fat or lymphatic tissue
• Debulking or contour resection of the feet to better fit into shoes
• Epiphysiodesis (surgical closure of the growth plate) to stop the growth in the longer leg
• Sclerotherapy of lymphatic and venous malformations
• Venous ablation
• Treatment of excessive blood clotting (coumadin, low molecular weight heparin, aspirin, inferior vena caval filter placement).

The course and prognosis of Klippel-Trenaunay Syndrome is highly variable, depending upon the types of vascular anomalies that are present. Patients with some overgrowth and varicose superficial veins can live normally if they receive the correct orthopedic treatment and wear an elastic compression stocking. Patients with severe lymphatic involvement may have more difficulty walking and may experience bleeding or infections. The formation of blood clots in the abnormal veins can result in serious problems, including pulmonary emboli (blood clots in the arteries to the lungs).