Superficial venous thrombosis (SVT) is perceived to have a benign prognosis. Among 844 patients with SVT, 24.9% also had deep venous thrombosis (DVT) or symptomatic pulmonary embolism.
Among 600 patients without DVT or pulmonary embolism at inclusion who were eligible for 3-month follow-up, 10.2% developed thromboembolic complications at 3 months despite 90.5% having received anticoagulants:
- pulmonary embolism 0.5%
- DVT 2.8%
- extension of SVT 3.3%
- recurrence of SVT 1.9%
A substantial number of patients with SVT exhibit venous thromboembolism at presentation, and some that do not can develop this complication in the subsequent 3 months.
References:
http://www.annals.org/content/152/4/218.short
Image source: Saphenous vein, Gray's Anatomy, 1918 (public domain).