The SOX Trial: Compression Stockings to Prevent the Post-Thrombotic Syndrome

The SOX Trial: Compression Stockings to Prevent the Post-Thrombotic Syndrome After Symptomatic Proximal Deep Venous Thrombosis

The purpose of this study is to determine whether elastic compression stockings used for 2 years are effective in preventing the post-thrombotic syndrome in patients with symptomatic proximal deep venous thrombosis.

The post-thrombotic syndrome (PTS) is a frequent, burdensome and costly condition that occurs in about one third of patients after an episode of deep vein thrombosis (DVT). Affected patients have chronic leg pain and swelling, and sometimes develop skin ulcers. At present, there is little to offer for the treatment of this condition. Prevention of PTS is the key to reducing its burden on patients and society. Elastic compression stockings (ECS) could be helpful in preventing PTS, however data on their effectiveness are scarce and conflicting.

Comparison(s): Knee-length, 30-40 mm Hg (Class II), graduated ECS worn on the DVT-affected leg daily for 2 years compared to knee-length, inactive (i.e. no compression) stocking, identical in appearance to active ECS, worn on the DVT-affected leg daily for 2 years.

Inclusion Criteria:

• Consecutive patients with a first, symptomatic, objectively confirmed proximal DVT diagnosed within the last 14 days (with or without concurrent distal DVT or pulmonary embolism)
• Who have no contraindications to standard treatment with heparin and/or warfarin, and
• Who provide informed consent to participate

Exclusion Criteria:

• Contraindication to compression stockings
• Limited lifespan (estimated < 6 months)
• Geographic inaccessibility preventing return for follow-up visits
• Inability to apply stockings daily and unavailability of a caregiver to apply stockings daily
• Treatment of acute DVT with thrombolytic agents