Rutosides for treatment of post-thrombotic syndrome

Background Post‐thrombotic syndrome (PTS) is a long‐term complication of deep venous thrombosis (DVT) that is characterised by pain, swelling, and skin changes in the affected limb. One in three patients with DVT will develop post‐thrombotic sequelae within five years. Rutosides are a group of compounds derived from horse chestnut (Aesculus hippocastanum), a traditional herbal remedy for treating oedema formation in chronic venous insufficiency (CVI). However, it is not known whether rutosides are effective and safe in the treatment of PTS. This is an update of the review first published in 2013. Objectives To determine the effectiveness (improvement or deterioration in symptoms) and safety of rutosides for treatment of post‐thrombotic syndrome (PTS) in patients with DVT compared to placebo, no intervention, elastic compression stockings (ECS) or any other treatment. Search methods For this update the Cochrane Vascular Group Trials Search Co‐ordinator searched the Specialised Register (last searched September 2015) and the Cochrane Register of Studies (CRS) (CENTRAL (2015, Issue 8)). Clinical trials databases were searched for details of ongoing and unpublished studies. Selection criteria Two review authors (JM and DNK) independently assessed studies for inclusion. Studies were included to allow the comparison of rutosides versus placebo or no treatment, rutosides versus ECS, and rutosides versus any other treatment. Two review authors (JM and SEY) extracted information from the trials. Disagreements were resolved by discussion. Data collection and analysis Data were extracted using designated data extraction forms. The Cochrane risk of bias tool was used for all included studies to assist in the assessment of quality. Primary outcome measures were the occurrence of leg ulceration over time (yes or no) and any improvement or deterioration of post‐thrombotic syndrome (yes or no). Secondary outcomes included reduction of oedema, pain, recurrence of deep venous thrombosis or pulmonary embolism, compliance with therapy, and adverse effects. All of the outcome measures were analysed using Mantel‐Haenzel fixed‐effect model odds ratios. The unit of analysis was the number of patients. Main results Ten reports of nine studies were identified following searching and three studies with a total of 233 participants met the inclusion criteria. Overall quality of the evidence using the GRADE approach was low or very low, predominantly due to the lack of both participant and researcher blinding in the included studies. The quality of the evidence was further limited as only three small studies contributed to the review findings. A subjective scoring system was used to obtain the symptoms of PTS so it was important that the assessors were blinded to the intervention. One study compared rutoside with placebo, one study compared rutosides with ECS and rutosides plus ECS versus ECS alone, and one study compared rutosides with an alternative venoactive remedy. Occurrence of leg ulceration was not reported in any of the included studies. There was a 29% odds of an improvement in PTS in the rutoside treated group versus placebo or no treatment, and lower rates of improvement in PTS in the rutoside treated group when compared with ECS, however these were statistically non‐significant. Lower rates of improvement in PTS were shown in the rutoside treated group when compared with an alternative venoactive remedy. More PTS deterioration was shown in the placebo or no treatment group when compared with rutosides but this was not statistically significant. Compared with ECS, rutosides showed higher odds of PTS deterioration but this was also not statistically significant. One study reported on adverse effects showing higher odds of mild adverse effects in the rutoside treated group compared to placebo but this was not statistically significant. Authors' conclusions There was no evidence that rutosides were superior to the use of placebo or ECS. Overall, there is currently limited and low or very low quality evidence that 'venoactive' or 'phlebotonic' remedies such as rutosides reduce symptoms of PTS. Mild side effects were noted in one study. The three studies included in this review provide no evidence for the use of rutosides in the treatment of PTS.