NEW YORK (Reuters Health) – Superficial venous thrombosis is often considered benign, but new research suggests that one in four patients also have deep venous thrombosis (DVT) or pulmonary embolism (PE). Moreover, many patients without DVT or PE on presentation will develop them in the next 3 months.

The findings, reported in the Annals of Internal Medicine for February 15, stem from a French multicenter investigation of 844 consecutive patients with symptomatic superficial venous thrombosis of the leg (that was at least 5 cm on compression ultrasonography).

According to lead author Dr. Herve Decousus, from INSERM/DHOS, Saint-Etienne, France, and colleagues, 24.9% of these patients also had DVT or symptomatic PE at presentation.

For 586 patients with isolated superficial venous thrombosis, the researchers had 3-month follow-up data. By that point, 58 (10.2%) had developed thromboembolic complications — despite the fact that 540 had received anticoagulants and “nearly all” received elastic stockings. Forty-six patients had symptomatic events: PE in 3, DVT in 15, extension of superficial venous thrombosis in 18, and recurrence of superficial venous thrombosis in 10. In the other 12 patients, complications were found on ultrasonography at day 10.

Predictors of complications at 3 months included male gender, history of DVT or PE, a prior cancer diagnosis, and absence of varicose veins.

For patients who present with symptomatic superficial venous thrombosis, compression ultrasonography to evaluate the extent of the thrombosis and to look for potential DVT “might be considered,” the authors suggest. They also recommend a high index of suspicion for PE and “close follow-up of patients with isolated superficial venous thrombosis.”

The study was funded, in part, by GlaxoSmithKline and Sanofi-Aventis, both of which market anti-thrombotic agents.

Reference:
Ann Intern Med 2010;152:218-224.