Diagnosis and treatment of superficial vein thrombosis

Superficial vein thrombosis (SVT) is a common disease, characterized by an inflammatory-thrombotic process in a superficial vein. Typical clinical findings are pain and a warm, tender, reddish cord along the vein. Until recently, no reliable epidemiological data were available. The incidence is estimated to be higher than that of deep-vein thrombosis (DVT) (1/1000). SVT shares many risk factors with DVT, but affects twice as many women than men and frequently occurs in varicose veins. Clinically, SVT extension is commonly underestimated, and patients may have asymptomatic DVT. Therefore, ultrasound assessment and exclusion of DVT is essential. Risk factors for concomitant DVT are recent hospitalization, immobilization, autoimmune disorders, age > 75 years, prior VTE, cancer and SVT in non-varicose veins. Even though most patients with isolated SVT (without concomitant DVT or PE) are commonly treated with anticoagulation for a median of 15 days, about 8% experience symptomatic thromboembolic complications within three months. Risk factors for occurrence of complications are male gender, history of VTE, cancer, SVT in a non-varicose vein or SVT involving the sapheno-femoral junction (SFJ). As evidence supporting treatment of isolated SVT was sparse and of poor quality, the large, randomized, double-blind, placebo-controlled CALISTO trial was initiated assessing the effect of fondaparinux on symptomatic outcomes in isolated SVT. This study showed that, compared with placebo, 2.5 mg fondaparinux given for 45 days reduced the risk of symptomatic thromboembolic complications by 85% without increasing bleeding. Based on CALISTO and other observational studies, evidence-based recommendations can be made for the majority of SVT patients. Further studies can now be performed in higher risk patients to address unresolved issues.