Systematic review Systematic review of foam sclerotherapy for varicose veins X. Jia 1 , G. Mowatt 1 , J. M. Burr 1 , K. Cassar 2 , J. Cook 1 and C. Fraser 1 1 Health Services Research Unit, University of Aberdeen, and 2 Aberdeen Royal Infirmary, NHS Grampian, Aberdeen, UK Correspondence to: X. Jia, Health Services Research Unit, University of Aberdeen, Third Floor, Health Sciences Building, Foresterhill, Aberdeen AB25 2ZD, UK (e-mail: x.jia@abdn.ac.uk) Background and method: Foam sclerotherapy is a potential treatment for varicose veins. A systematic review was undertaken to assess its safety and efficacy. Results: Sixty-nine studies were included. The median rates of serious adverse events, including pulmonary embolism and deep vein thrombosis, were less than 1 per cent. The median rate of visual disturbance was 1·4 per cent, headache 4·2 per cent, thrombophlebitis 4·7 per cent, matting/skin staining/pigmentation 17·8 per cent and pain at the site of injection 25·6 per cent. The median rate of complete occlusion of treated veins was 87·0 per cent and for recurrence or development of new veins it was 8·1 per cent. Meta-analysis for complete occlusion suggests that foam sclerotherapy is less effective than surgery (relative risk (RR) 0·86 (95 per cent confidence interval (c.i.) 0·67 to 1·10)) but more effective than liquid sclerotherapy (RR 1·39 (95 per cent c.i. 0·91 to 2·11)), although there was substantial heterogeneity between studies. Conclusion: Serious adverse events associated with foam sclerotherapy are rare. There is insufficient evidence to allow a meaningful comparison of the effectiveness of this treatment with that of other minimally invasive therapies or surgery. Paper accepted 23 March 2007 Published online in Wiley InterScience (www.bjs.co.uk). DOI: 10.1002/bjs.5891 Introduction Treatment options for varicose veins include compres- sion hosiery, endovenous laser ablation, radiofrequency ablation, conventional operation, subfascial endoscopic perforator surgery and sclerotherapy. Sclerotherapy may use a liquid or a foam agent. Liquid sclerotherapy causes an inflammatory reaction and consequent venous occlusion 1 . Foam sclerotherapy is a modification of liquid sclerother- apy in which the liquid is transformed into foam by mixing it with air 2–4 or other gas, such as oxygen or carbon dioxide. Foam sclerotherapy is a potential treatment for all cat- egories of venous disease, although currently its use in the UK is ‘off licence’. Anaphylaxis and vascular events, such as stroke, myocardial infarction and thromboem- bolism, are potential complications. Other adverse events associated with foam sclerotherapy include transient visual disturbance, cutaneous necrosis or ulceration, and local effects such as ‘minor’ vein thrombosis, thrombophlebitis, local neurological injury and skin pigmentation. This study reviews the safety and efficacy of foam sclerotherapy. Methods Search strategy Electronic searches were conducted to identify reports of published and unpublished studies, and included abstracts from conference proceedings and other grey literature sources. There were no restrictions in terms of language or publication year. The search strategies were designed to be highly sensitive, including both appropriate subject heading and text word terms. Databases searched included Medline (1 January 1966 to May week 2 2006), Embase (1 January 1980 to week 20 2006), Medline in-process (23 May 2006), Biosis (1 January 1969 to 19 May 2006), Science Citation Index (1 January 1981 to 20 May 2006), ISI Proceedings (1 January 1990 to 23 June 2006), Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2006), Conference Papers Index (1 January 2000 to June 2006), Cochrane Database of Systematic Reviews (The Cochrane Library, Issue 2, 2006), Database of Abstracts of Reviews of Effectiveness (April 2006), Health Technology Assessment Database (April 2006), National Research Register (Issue 2, 2006), Copyright  2007 British Journal of Surgery Society Ltd British Journal of Surgery 2007; 94: 925–936 Published by John Wiley & Sons Ltd