Patients with Klippel-Trénaunay syndrome can have numerous complications including skin breakdown and ulceration, bleeding and secondary infection.
If the lesion extends deeper in tissue, internal organs such as the sacs that hold the lungs (pleura), spleen, liver, bladder and colon may also be affected. When this happens, internal bleeding or clotting can occur.
Varicosities may affect the superficial and deep venous systems. Pain and lymphedema (swelling of the extremities due to stoppage of lymph flow caused by malformed lymphatic vessels) are common.
Complications due to varicosities include abnormal skin sensations such as burning or tingling (paresthesias), skin ulcers, blood clots in the lung (pulmonary emboli), inflammation and clots of blood vessels in the legs, and skin and soft tissue infection (cellulitis).
Hypertrophy of a limb can lead to vertebral scoliosis, gait abnormalities and compromise of function.
Malformations can be localized in the joint and cause damage secondary to bleeding.