Below-Knee Stockings Halve Complication Rate From Post-Thrombotic Syndrome

Wearing below-knee stockings after deep vein thrombosis (DVT) reduced the incidence of complications from post-thrombotic syndrome (PTS) by nearly 50% for up to two years, according to the results of a randomized trial published in the Aug. 17 issue of the Annals of Internal Medicine. The editorialist gives a practical approach.

"Because only limited evidence suggests that elastic stocking prevent the post-thrombotic syndrome in patients with symptomatic deep venous thrombosis (DVT), these stockings are not widely used," write Paolo Prandoni, MD, PhD, from the University Hospital of Padua in Italy, and colleagues.

One third to one quarter of patients with DVT develop complications including swelling, skin discoloration and numbness, chronic pain, induration of the skin, and leg ulcerations. Elastic compression stockings exert graduated pressure on the lower leg and can be purchased in medical supply stores for U.S. $30 to $50.

In this study, 180 patients diagnosed with a first episode of DVT were randomized before discharge to wear below-knee graded compression elastic stockings (30 to 40 mm Hg at the ankle) every day for two years or to not wear these stockings. All patients also received appropriate anticoagulant therapy for DVT and were followed up for up to five years. PTS severity was scored using a standardized scale.

After two years, the group wearing compression stockings had developed fewer post-thrombotic complications, which occurred in 44 (49%) of 90 controls (severe in 10) and in 23 (26%) of 90 patients wearing elastic stockings (severe in 3). The overall incidence of complications was reduced from 49% to 26%, and the incidence of severe complications was reduced from 12% to 3.5%. However, the stockings did not reduce recurrent episodes of DVT.

The cumulative incidence of PTS in the control group vs the stocking group was 40.0% (95% confidence interval [CI], 29.9% to 50.1%) vs 21.1% (95% CI, 12.7% to 29.5%) after six months, 46.7% (95% CI, 36.4% to 57.0%) vs 22.2% (95% CI, 13.8% to 30.7%) after one year, and 49.1% (95% CI, 38.7% to 59.4%) vs 24.5% (95% CI, 15.6% to 33.4%) after two years. Compared with the control group, the hazard ratio for PTS in the elastic stockings group was 0.49 (95% CI, 0.29 to 0.84; P = .01) after adjustment for baseline characteristics.

Study limitations were lack of double-blind design and inability to explain the mechanism of reduced risk of PTS.

New Medical Service, Linea Flebologica Flebysanin in Rovigo, Italy, supported this study. The authors report no potential financial conflicts of interest.

In an accompanying editorial, Jeffrey S. Ginsberg, MD, FRCPC, from McMaster University in Hamilton, Ontario, offers a practical approach, and Dr. Ginsberg recommends that stocking therapy be routinely offered after DVT.

"The stockings are sometimes hard to get on; some find them unattractive, and if the patient has only mild ankle swelling at the end of the day, frequently elevating the legs or avoiding long bouts of standing or sitting might be enough to reduce the symptoms," Dr. Ginsberg says. "Still, elastic compression stockings are a relatively inexpensive, noninvasive way to reduce risk of complications from DVT, and physicians and patients should consider them."

Dr. Ginsberg notes that severe symptoms usually indicate extensive thrombus, causing massive edema, for which a lightweight stocking such as support hose may be useful until the edema resolves.

"If symptoms persist or worsen despite these measures, or ulceration seems imminent (as evidenced by severe skin changes), a full-strength stocking (30 to 40 mm Hg of pressure at the ankle) can be prescribed," Dr. Ginsberg writes. "However, if symptoms subside and the patient remains asymptomatic or has only trivial persistent signs or symptoms with little or no effect on quality of life (for example, venous ectasia or mild ankle swelling at the end of the day), stockings can be avoided and the patient can be followed for clinically important signs and symptoms of the post-thrombotic syndrome."

Dr. Ginsberg has received a Career Investigator Award from the Heart and Stroke Foundation of Ontario. The author reports no potential financial conflicts of interest.