Sclerosants

Sclerosants are chemical agents injected into abnormal vessels or lymphatic channels to cause endothelial injury and subsequent inflammation, thrombosis, and fibrosis that occludes the lumen. They are used to treat varicose veins and venous malformations, as well as lymphatic malformations. They may also be used for pleurodesis in select settings.

Common agents include polidocanol and sodium tetradecyl sulfate, available as liquids and foams; hypertonic saline; absolute ethanol; ethanolamine oleate. Other agents used for lymphatic lesions include bleomycin, doxycycline, and OK-432 (picibanil).

Administration is usually percutaneous and image-guided (often ultrasound) with injection into the lesion or vessel. Foam formulations are sometimes used to increase endothelial contact. Dosing is tailored to lesion size, location, and response.

Risks include local pain, swelling, inflammation, and phlebitis; skin necrosis or pigmentary changes if extravasation occurs; non-target vessel injury; infection; and, rarely, systemic toxicity or anaphylaxis.

Contraindications include infection at the injection site, hypersensitivity to the agent, pregnancy for some sclerosants, and impairment of coagulation or significant comorbidity that increases risk. The choice of sclerosant and technique depends on the treated vascular or lymphatic lesion, with outcomes influenced by practitioner experience and patient factors.