Association Between Superficial Vein Thrombosis and Deep Vein Thrombosis of the Lower Extremities

Objective: To evaluate the occurrence of deep vein thrombosis (DVT) in patients with superficial vein thrombosis (SVT). Design: A prospective study in patients with sonographically proven SVT. Setting: Outpatient department of the Department of Dermatology, Medical University of Graz. Patients: Forty-six consecutive patients with superficial vein thrombosis were enrolled. Intervention: Every patient underwent color-coded duplex sonography of both lower extremities at the beginning of the study. Main Outcome Measures: Important risk factors (eg, history of thromboembolic events, recent immobilization, active malignant disease, and the use of oral contraceptives) were investigated. Results: In 24% of our patients, a concomitant, mostly asymptomatic DVT was found. In 73% of these patients, the DVT occurred in the affected leg, in 9% in the contralateral leg, and in 18% in both legs. The calf muscle veins were most commonly involved. In all patients with DVT, the SVT was located on the lower leg and the D-dimer findings were positive. Conclusions: Superficial vein thrombosis is not a life-threatening disease, but the risk of concomitant DVT cannot be ignored. Color-coded duplex sonography should be performed in patients with SVT to rule out DVT.