Treatment algorithms for acute venous thromboembolism

Venous thromboembolism (VTE) is common in the United States, with an annual incidence of 1 to 2 cases per 1000 people, or 300,000–600,000 cases per year. 1 Deep venous thrombosis (DVT), one manifestation of VTE, is a leading cause of morbidity and mortality. 2 While isolated calf DVTs rarely cause symptoms or pulmonary emboli (PE), more proximal DVTs (iliac, femoral, popliteal) can be symptomatic, and 40%–50% of patients present with concurrent PE evidence on lung scans. 3 Together, DVT and PE may be responsible for over 100,000 deaths each year. 2 Post-thrombotic syndrome (PTS) is the most common chronic complication of DVT, most commonly reported after proximal DVTs (iliac and common femoral). 4, 5 PTS is characterized by a range of clinical symptoms from minor lower extremity discomfort to severe limb pain, edema, heaviness, skin changes, and irreversible venous ulceration. 4 Once PTS develops, treatment is frequently supportive. While much less common than PTS, phlegmasia is another serious complication of iliofemoral DVT, ultimately leading to advanced lower extremity ischemia and gangrene. Prompt intervention is necessary, as phlegmasia is associated with an increased risk of limb loss and mortality.