Background: Injection sclerotherapy is widely used for superficial varicose veins. The treatment aims to obliterate the lumen of varicose veins or thread veins. There is limited evidence regarding its efficacy.

Objectives: To determine whether sclerotherapy is effective in improving symptoms and cosmetic appearance and has an acceptable complication rate; to define rates of symptomatic or cosmetic varicose vein recurrence following sclerotherapy.

Search strategy: We searched the Cochrane Peripheral Vascular Diseases Group trials register (April 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2006), MEDLINE and EMBASE (both inception to April 2006) and reference lists of articles. Manufacturers of sclerosants were contacted for additional trial information.

Selection criteria: Randomised controlled trials (RCTs) of injection sclerotherapy versus graduated compression stockings (GCS) or 'observation', or comparing different sclerosants, doses, formulations and post-compression bandaging techniques on people with symptomatic and/or cosmetic varicose veins or thread veins were considered for inclusion in the review.

Data collection and analysis: Data were extracted by authors and Review Group Co-ordinators independently.

Main results: Seventeen studies were included. One study comparing sclerotherapy to GCS in pregnancy found that sclerotherapy improved symptoms and cosmetic appearance. Three studies comparing sodium tetradecyl sulphate (STD) to alternative sclerosants found no significant differences in outcome or complication rates; another study found that sclerotherapy with STD led to improved cosmetic appearance compared with polidocanol, although there was no difference in symptoms. Sclerosant plus local anaesthetic reduced the pain from injection (one study) but had no other effects. Two studies compared foam- to conventional sclerotherapy; one found no difference in failure rate or recurrent varicose veins; a second showed short-term benefit from foam in terms of elimination of venous reflux. The recanalisation rate was no different between the two treatments. One study comparing Molefoam and Sorbo pad pressure dressings found no difference in erythema or successful sclerosis. The degree and duration of elastic compression had no significant effect on varicose vein recurrence rates, cosmetic appearance or symptomatic improvement.

Authors' conclusions: Evidence from RCTs suggests that the choice of sclerosant, dose, formulation (foam versus liquid), local pressure dressing, degree and length of compression have no significant effect on the efficacy of sclerotherapy for varicose veins. The evidence supports the current place of sclerotherapy in modern clinical practice, which is usually limited to treatment of recurrent varicose veins following surgery and thread veins. Surgery versus sclerotherapy is the subject of a further Cochrane Review.