3rd April 2024

Introduction

Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT refers to occluding or non-occluding thrombi in the deep veins which can embolise, causing pulmonary emboli. The annual incidence of VTE is around 2/1000 in the general population. Risk factors include:

• Thrombophilia (factor V Leiden mutation, prothrombin gene mutation, protein C and S deficiency, anti-thrombin deficiency, and antiphospholipid antibody syndrome)
• Previous VTE
• Age over 40 years 
• Recent surgery
• Obesity
• Varicose veins
• Prolonged travel
• Acute medical illness
• Cancer
• Immobility
• Pregnancy
• Drugs: 5 fluorouracil, oestrogen-containing contraceptives, hormone replacement therapy, tamoxifen and cisplatin 
• Inflammatory bowel disease, nephrotic syndrome, blood transfusions 
• Vessel wall damage (venous harvest and central venous catheterisation)