Randomised trial of effect of compression stockings in patients with symptomatic proximal-vein thrombosis.

BACKGROUND Post-thrombotic syndrome varies from mild oedema to incapacitating swelling with pain and ulceration. We investigated the rate of post-thrombotic syndrome after a first episode of deep-vein thrombosis and assessed the preventive effect of direct application of a sized-to-fit graded compression stocking. METHODS Patients with a first episode of venogram-proven proximal deep-vein thrombosis were randomly assigned no stockings (the control group) or made-to-measure graded compression elastic stockings for at least 2 years. Post-thrombotic syndrome was assessed with a standard scoring system that combined clinical characteristics and objective leg measurements. Patients were assessed every 3 months during the first 2 years, and every 6 months thereafter for at least 5 years. The cumulative incidence of mild-to-moderate post-thrombotic syndrome was the primary outcome measure. FINDINGS Of the 315 consecutive outpatients considered for inclusion, 44 were excluded and 77 did not consent to take part. 194 patients were randomly assigned compression stockings (n = 96) or no stockings (n = 98). The median follow-up was 76 months (range 60-96) in both groups. Mild-to-moderate post-thrombotic syndrome (score > or = 3 plus one clinical sign) occurred in 19 (20%) patients in the stocking group and in 46 (47%) control-group patients (p < 0.001). 11 (11%) patients in the stocking group developed severe post-thrombotic syndrome (score > or = 4), compared with 23 (23%) patients in the control group (p < 0.001). In both groups, most cases of post-thrombotic syndrome occurred within 24 months of the acute thrombotic event. INTERPRETATION About 60% of patients with a first episode of proximal deep-vein thrombosis develop post-thrombotic syndrome within 2 years. A sized-to-fit compression stocking reduced this rate by about 50%.