Background: Conservative therapy of chronic venous insufficiency (CVI) consists largely of compression treatment. However, this often causes discomfort and has been associated with poor compliance. Therefore, oral drug treatment is an attractive alternative.
Objectives: To review the evidence from rigorous clinical trials assessing the efficacy and safety of oral horse chestnut seed extract (HCSE) versus placebo, or other treatments for CVI.
Search strategy: Randomised controlled trials (RCTs) of HCSE for chronic venous insufficiency were sought through EMBASE (inception to December 2001), MEDLINE and AMED (from inception to February 2004), The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2004), the Specialised Trials Register of the Cochrane Peripheral Vascular Diseases Group (last searched February 2004), and Phytobase (from inception to January 2001, no longer operational). Manufacturers of HCSE preparations and experts on the subject were contacted for published and unpublished material. There were no restrictions on language.
Selection criteria: RCTs were included if they compared oral HCSE mono-preparations with placebo, or other treatments, in patients with CVI. Trials assessing HCSE as one of several active components in a combination preparation, or as a part of a combination treatment, were excluded.
Data collection and analysis: Two reviewers independently selected and assessed methodological quality of the studies using a standardised scoring system, and extracted data. Disagreements concerning evaluation of individual trials were resolved through discussion.
Main results: Overall, there appeared to be an improvement in CVI related signs and symptoms with HCSE compared with placebo. Leg pain was assessed in seven placebo-controlled trials. Six reported a significant reduction of leg pain in the HCSE groups compared with the placebo groups, while another reported a statistically significant improvement compared with baseline. One trial suggested a weighted mean difference (WMD) of 42.4 mm [95% confidence interval (CI) 34.9 to 49.9] measured on a 100 mm visual analogue scale. Leg volume was assessed in six placebo-controlled trials. Meta-analysis of five trials (n = 289) suggested a significant reduction in favour of HCSE compared with placebo (WMD 56.3 ml [95% CI 24.1 to 88.5]). One trial indicated that HCSE may be as effective as compression stockings at reducing leg volume. Adverse events were usually mild and infrequent.
Reviewers' conclusions: The evidence presented implies that HCSE is an efficacious and safe short-term treatment for CVI. However, several caveats exist and more rigorous RCTs are required to assess the efficacy of this treatment option.