VTE

Venous thromboembolism (VTE) refers to the formation of blood clots in the venous circulation, encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT typically involves the deep veins of the legs or pelvis; PE occurs when a thrombus breaks loose and occludes a pulmonary artery.

VTE is a common, potentially life-threatening condition. It is a leading cause of preventable hospital deaths. Incidence and risk increase with age and comorbidity. Known risk factors include surgery, cancer, immobilization, obesity, pregnancy and the postpartum period, hormonal therapy, inherited thrombophilias, prior VTE, and prolonged air travel.

Pathophysiology: Virchow's triad—hypercoagulability, venous stasis, and endothelial injury—contributes to clot formation. DVTs in proximal veins carry higher risk of PE. Many DVTs are asymptomatic.

Symptoms and diagnosis: DVT presents with leg swelling, pain, and warmth; PE with chest pain, shortness of breath, and tachycardia. Tests include D-dimer for low-probability cases, compression ultrasonography for DVT, and CT pulmonary angiography for PE; V/Q scan as an alternative.

Treatment: Anticoagulation is standard, with options such as low-molecular-weight heparin, unfractionated heparin, and direct oral anticoagulants, often transitioning to a DOAC or warfarin. Duration is usually at least 3 months; longer therapy for recurrent VTE or persistent risk. Massive PE may require thrombolysis or embolectomy; IVC filters in select cases.

Prevention: risk-based prophylaxis in hospital settings, combining mechanical methods and pharmacologic prophylaxis for high-risk patients, along with early mobilization after surgery.

Prognosis and complications: with treatment, outcomes improve, but VTE carries recurrence risk and long-term effects such as post-thrombotic syndrome after DVT and chronic thromboembolic pulmonary hypertension after PE.