Stephan Moll, MD writes… Up to 50 % of patients with a clot in the veins of the leg (deep vein thrombosis; DVT) develop some long-term leg symptoms – chronic swelling, pain, heaviness, cramping, skin discoloration or dryness. These symptoms are called “postthrombotic syndrome” or PTS.
Two previous studies had suggested that wearing elastic compression stockings decreased the risk of developing PTS [ref 2,3]. However, the quality of those 2 studies was limited by (a) their small size, (b) the fact that they were single-center trials, and (c) the fact that they were not placebo-controlled. Based on these 2 studies compression stockings (30/40 mm mercury) have often been suggested to be worn by patients with DVT to prevent PTS [ref 4].
A new publication in the Lancet [ref 1] shows that elastic compression stockings after a first episode of leg DVT do NOT prevent postthrombotic syndrome (PTS) as assessed over 2 years. This is a good-quality, large randomized placebo-controlled trial, called the SOX-trial.
The SOX Trial
This was a multicenter, randomized, placebo-controlled trial in patients with acute first episode of proximal DVT (proximal DVT= the clot extends above the knee). Patients wore either 30-40 mm Hg graduated elastic compressions stockings or “placebo stockings” with identical appearance but less than 5 mm Hg compression at the ankle. The follow-up period was 2 years.
- 806 patients were enrolled: 410 received elastic compression stockings, 396 placebo stockings.
- PTS (as assessed by the so-called “Ginsberg’s criteria”) developed in 14.2 % in the active stocking group, and in 12.7 % in the placebo stocking group (hazard ratio 1.13, 95% CI 0.73-1.76; p=0.58).
- By the so-called Villalta score (a different PTS scoring system) there was also no difference in PTS development between the 2 groups: 7.5 % and 5,8 % developed severe PTS in the active stocking group and the placebo stocking group, respectively; 8.3 % and 10. 5 moderate PTS; 33 % and 32.1 % mild PTS; and 51.3 % and 51.4 % no PTS.
Elastic compression stockings did not prevent PTS in patients with a leg DVT.
This is a very interesting and relevant study. Compression stockings used to be fairly strongly recommended by many physicians, in the belief that they would prevent postthrombotic syndrome. We now have evidence from a large and well-done trial that they do NOT prevent PTS. Therefore, the discussion with the patient now is that he/she can wear stockings if he/she feels that they make the leg feel better – less pain or less swelling while being worn. However, I now discuss with my patients that the stockings do NOT have a lasting beneficial effect – thus, if they do not make the leg feel better or if they are actually uncomfortable to wear, then there is no reason to wear them.
- Kahn SR et al. Compression stockings to prevent post-thrombotic syndrome: a randomised placebo-controlled trial. Lancet, published online Dec 6, 2013.
- Brandjes DPM et al. Randomised trial of effect of compression stockings in patients with symptomatic proximal-vein thrombosis. Lancet 1997; 349: 759–62.
- Prandoni P, et al. Below-knee elastic compression stockings to prevent the post-thrombotic syndrome: a randomized, controlled trial. Ann Intern Med 2004; 141: 249–56.
- Kearon C et al. Antithrombotic Therapy for VTE – Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2_suppl):e419S-e494S.
Disclosures: I have no financial conflict of interest.
Last updated: Dec 18th, 2013