Klippel-Trenaunay (KT) Syndrome and Varicose Veins

What is Klippel-Trenaunay syndrome?

Klippel-Trenaunay syndrome (KTS) is a rare condition in which blood vessels, soft tissue and sometimes bone develop abnormally before birth. It is a type of venous malformation : the veins did not form in the usual pattern while the baby was growing. It is not caused by anything a parent did during pregnancy, and it is not contagious.

Most people with KTS have three features, often called the classic triad:

• A capillary birthmark (nevus, often described as wine-colored or port-wine), usually on the affected leg.
• Varicose veins or venous malformations , which may be visible from early childhood. In some people the deep veins are underdeveloped (hypoplasia) or missing (aplasia).
• Overgrowth (hyperplasia) of the soft tissue and skeleton of one limb, so one leg may be longer or wider than the other.

Severe cases can also involve the bones or connective tissue. Some people have red spots or skin hemangiomas, and similar vascular changes are sometimes found in the spine or head.

How is KT syndrome different from ordinary varicose veins?

Ordinary varicose veins develop over years, usually because valves in normal veins weaken and blood flows backward (reflux). In KT syndrome the problem is structural and present from birth. Unusual veins, such as a large vein running along the outer side of the leg, may carry much of the leg's blood.

This difference matters for treatment. If the deep veins are weak or absent, the abnormal surface veins may be doing essential work. Closing them without a full map of the circulation could make swelling and congestion worse.

What symptoms does KT syndrome cause?

Symptoms vary widely, from a mild birthmark to a limb that is heavy and painful every day. Common complaints include:

• Aching, heaviness and swelling in the affected leg, often worse after standing
• Visible, bulging veins that may enlarge with age
• Differences in leg length or size, which can affect walking and posture
• Skin changes, bleeding from surface vessels, or slow-healing wounds
• Episodes of painful, tender veins caused by small clots ( superficial thrombophlebitis )

People with venous malformations can also have a higher tendency to form blood clots. Sudden swelling of the whole leg, chest pain or breathlessness needs emergency care immediately; see our page on deep vein thrombosis .

How does LEDAS diagnose KT syndrome?

At LEDAS, diagnosis starts with a detailed duplex ultrasound examination on Philips EPIQ Elite equipment. The scan answers three practical questions:

1. Are the deep veins present and working? This is the single most important question.
2. Where are the abnormal superficial veins, and which way does the blood flow in them?
3. What size are the perforator veins and where are they? Perforators connect the surface and deep systems.

Because KT syndrome affects more than veins, some patients also need imaging such as MRI, or assessment by orthopedic, dermatology or pediatric specialists. Dr. Kim Byoung Joon will explain your ultrasound findings on screen with you and tell you honestly if another specialist should be involved.

What treatment options are available?

When the deep veins are normal

If ultrasound shows a functioning deep venous system, abnormal surface veins can often be treated. The approaches most often used are laser treatment ( EVLT ) for larger refluxing veins and ultrasound-guided foam sclerotherapy for tortuous or hidden veins. At LEDAS these are done under local anesthesia, with no incision and same-day discharge.

When the deep veins are underdeveloped

If the deep veins are absent or very small, procedures that close surface veins are usually avoided. Care is then conservative :

• Well-fitted medical compression stockings to reduce swelling and heaviness
• Anticoagulant (blood-thinning) medicine when clot risk is high
• Antibiotics if skin infection develops
• Skin care, leg elevation and regular walking

Every treatment has possible side effects, so decisions are made one patient at a time. For an overview of how LEDAS approaches KTS care, read KT syndrome vein management .

Living with KT syndrome: long-term follow-up

KT syndrome is lifelong. Veins can change with growth, pregnancy and age, so regular review matters. LEDAS recommends follow-up ultrasound every one to two years, or whenever an overseas patient visits Korea, so new problems are found early. Between visits, contact us if the leg suddenly becomes more swollen, painful, discolored or develops a wound.

KT syndrome care depends on the deep veins

Klippel-Trenaunay syndrome – frequently asked questions