Patients with SVT may also have DVT

Many patients who present with superficial venous thrombosis also either have or soon develop venous thromboembolism, according to a new study.

The French cohort study included 844 patients who saw a vascular medicine specialist for a symptomatic superficial venous thrombosis (SVT) of the lower limbs that was at least 5 cm on compression ultrasonography. At the first visit, 24.9% of the patients were found to also have a deep venous thrombosis (DVT) or symptomatic pulmonary embolism. Over three months of follow-up, 10% of the remaining patients developed thromboembolic complications, even though 90% of them received anticoagulants.

Patients who were male, had a history of DVT or pulmonary embolism, had previous cancer, or no varicose veins--risk factors that have been confirmed by other studies--were at higher risk of complications during follow-up. This study was limited by a premature termination of enrollment with only about half the patients originally called for. The results were published in the Feb. 16 Annals of Internal Medicine.

The findings show that SVT is not entirely benign, study authors concluded. Clinicians should consider using compression ultrasonography in SVT patients as well as watching for symptoms of pulmonary embolism (and testing when symptoms are spotted) and following up closely with all of these patients, the researchers said. They also called for more research into the benefits and risks of using systemic anticoagulant therapy to treat SVT and prevent DVT.