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Klippel-Trenaunay syndrome.
Medical expert of the article
Last reviewed: 05.07.2025
[ Epidemiology
The frequency of occurrence of the defect is low: over the last century, about 400 observations have been described, and no more than 100 of them are in childhood. The lower limbs are mainly affected. Klippel-Trenaunay syndrome is more common in boys, it is predominantly unilateral, and manifests itself from the birth of the child.
What causes Klippel-Trenaunay syndrome?
The pathogenetic mechanism of this disease is a congenital partial and complete block of venous outflow from the affected limb. Blockade of the main veins leads to chronic phlebohypertension in the distal parts of the limb and the collateral vein system. Unfavorable hemodynamic conditions (increased arterial resistance and overflow of capillaries and venules with blood) cause trophic disorders, lymphostasis and the development of a sclerotic process in all tissues of the limb. Disruption of blood flow in the deep veins can be caused by aplasia or hypoplasia of the vein, hyperplasia, compression of the vein from the outside by cords, embryonic adhesions, abnormal muscle, aberrant arteries.
How does Klippel-Trenaunay syndrome manifest itself?
The defect is characterized by a triad of symptoms: dilation of superficial veins, elongation or thickening of the limb, angiomas. Vascular and pigment spots are detected on the skin of the affected limb.
The most constant symptom is the expansion of superficial veins, which has the following features: expansion by the trunk type, localization of varicose veins on the outer side of the limb, absence of pulsation in any sound phenomena above the nodes. The second important symptom is the progressive lengthening and thickening of the affected limb. Vascular spots (capillary dysplasia) and angiomas are noted in 70% of patients. In addition to these symptoms, trophic changes in the skin (hyperhidrosis, hypertrichosis, hyperkeratosis, trophic ulcers), changes in the musculoskeletal system, bleeding, inflammation are possible.
Laboratory and instrumental studies
Recognition of the disease is based on a comparison of clinical and special research methods. The leading place in diagnostics is occupied by angiography, which allows not only to assess the degree of damage to the venous system, but also to clarify the localization of the main vein block. The absence of a vein shadow on one of the segments or the entire limb, characteristic of Klippel-Trenaunay syndrome, and contrasting of embryonic veins are revealed.
Rheography reveals an increase in peripheral arteriolar resistance. And measurement of venous pressure shows a significant increase in the latter compared to the opposite side.
Differential diagnostics
Differential diagnostics are performed with congenital arteriovenous communications, similar only in external signs, but having other hemodynamic disorders, consisting in a rapid discharge of arterial blood into the venous bed. In this case, pulsation of veins, an increase in local temperature, sound phenomena above the vessels are noted. When comparing clinical, morphological and functional data, a certain staging of the process was discovered: compensated hemodynamic disorders - in children under 2-5 years old, subcompensated - up to 5-7 years old, the stage of chronic venous insufficiency - over 7 years old. Therefore, it is most advisable to operate on such children at the age of 2 to 5 years.
How is Klippel-Trenaunay syndrome treated?
Treatment of deep vein malformations of the lower extremities is exclusively surgical, aimed at restoring physiological blood flow through the deep veins. In case of hypoplasia and external compression, phlebolysis is performed, which helps to normalize blood flow. In case of severe hypoplasia or aplasia, microsurgical techniques are used to excise the defective area and replace it with a fragment of the contralateral great saphenous vein together with the valve. A similar operation is also possible in case of complete aplasia of the deep veins.
What is the prognosis for Klippel-Trenaunay syndrome?
The prognosis is relatively favorable with timely treatment of the defect.