People who have had a deep vein thrombosis (DVT) can develop post-thrombotic syndrome. This is caused by long-term clots in the affected leg and poor venous blood flow, resulting in leg pain, swelling ankles and hardened discoloured skin. The symptoms are worsened with prolonged standing or sitting and may limit lifestyle and day-to-day activities. In severe cases, venous ulcers, open sores that do not heal, also develop.
Wearing circular bandages or compression stockings after initial blood thinning (anticoagulant) treatment for DVT is used to reduce the likelihood of post-thrombotic syndrome and reduce symptoms. With severe swelling of the leg (oedema), a machine can be used to apply pressure to the leg to improve blood circulation. The review authors identified two trials investigating the effectiveness of these physical treatments for post-thrombotic syndrome. The first trial randomized 12 women and three men with a mean age of 60 years to receiving mechanical pressure using an extremity pump applying either a therapeutic 50 mm Hg pressure or low 15 mm Hg pressure twice daily for 20 minutes for one month. The participants then changed to the other pressure for a month. Twelve of the 15 participants preferred therapeutic pressure levels and nine continued to use the compression pump after the trial had finished, with small improvements in symptoms. The second trial randomly assigned 35 men and women who had experienced a DVT 12 months previously to wearing elastic compression stockings, knee or thigh high, or placebo stockings that were one to two sizes too large. Wearing correct fitting compression stockings showed no differences from placebo. After three months, 11 of 18 people wearing compression stockings failed to have improved symptoms or were still prevented from performing their daily activities for five or more days in any three month period compared with 10 of 17 wearing placebo stockings. No adverse effects were reported. The studies were too small and of too short a duration to draw strong conclusions.
There is some evidence of a beneficial effect of intermittent pneumatic compression units, but the study was too small and of too short a duration to draw strong conclusions. Further research is needed in order to assess whether intermittent pneumatic compression units give long term reduction and relief of the symptoms caused by post-thrombotic syndrome, and prevent deterioration and leg ulceration. The use of elastic compression stockings to treat post-thrombotic syndrome cannot be supported on the basis of the currently available data.
Post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis characterised by chronic complaints, swelling, and skin changes in the affected limb. One in every three people with deep vein thrombosis develops post-thrombotic complications within five years.
To assess the effectiveness of compression therapy in people with stage I and II post-thrombotic syndrome according to the classification of Widmer. Interventions of interest included elastic compression stockings and mechanical devices, compared with no intervention and with each other.
The Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (last searched November 2006), and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 4, 2006). In addition, journals, conference proceedings and bibliographies were handsearched. Personal contact with other investigators involved in the clinical area was sought to get information about missed or unpublished studies.
Trials that evaluated compression therapy for stage I and II (Widmer) post-thrombotic syndrome. Primary outcomes were leg ulceration, or deterioration of post-thrombotic syndrome. There were no restrictions on date or language. One author (DNK) assessed titles and abstracts for relevance. This was verified independently by a second author (MWCS).
Details of eligible studies were extracted and summarised using data extraction sheets. Data extraction was undertaken by one author (DNK) and verified by a second author (MHP).
Only two trials were identified that addressed physical treatment of post-thrombotic syndrome. Both trials were initiated by the same group of investigators. A cross-over study lasting two months compared low and high pressure with intermittent compression units for severe post-thrombotic syndrome. This showed a beneficial effect of higher pressures. The second study, in people with mild to moderate post-thrombotic symptoms, showed no effect of elastic compression stockings (30-40 mm Hg at the ankle region) when compared to 'placebo' stockings that were one to two sizes too large.