Venous malformations (VM) are the commonest types of vascular malformations, with an appropriate clinico-radiological diagnostic pathway being critical for establishing the correct diagnosis, mapping the extent of disease and involvement of important structures, guiding appropriate therapy, and predicting prognosis. Ultrasound (US) with color Doppler examination is the first-line radiological investigation with magnetic resonance imaging being used for further evaluation, providing the exact lesion extent and involvement of muscles, bones, and neurovascular bundles. Direct puncture phlebography of the lesion confirms the diagnosis and classifies the lesion in four types. Type 1 is an isolated malformation without peripheral drainage, type 2 malformation drains into normal veins, type 3 malformation drains into dilated veins, and type 4 malformation represents dysplastic venous ectasia. Treatment is sought for cosmetic reasons, pain, and functional issues. Sclerotherapy is the first-line treatment and image guidance, either US or phlebographic, is employed for the same. Various techniques are described including double or multiple puncture technique, subtraction-guided technique, filling defect technique, or a combination of these. Various sclerosants have been used including dry ethanol, polidocanol, ethanolamine oleate, sodium tetradecyl sulfate, sodium morrhuate, OKC 432, bleomycin, and doxycycline, either in liquid form or as microfoam prepared using Tessari's technique. Typically, multiple sessions are needed and the lesions may recur; however, overall response rate, quality of life improvement, and patient satisfaction are significantly improved. Local complications like pain, swelling, and ulcerations are common. Major complications of sclerotherapy are infrequent; however, pulmonary embolism, stroke, vision loss, compartment syndrome, tissue necrosis, hemolysis, anaphylaxis, nerve palsy, and pulmonary complications do occur and the patient and treating physicians should be aware of.
