embolisms

An embolism is a sudden blockage of a blood vessel by an embolus, a material that travels through the circulation from a distant site. Emboli can be solid (eg, a thrombus or cholesterol crystal), liquid (fat droplets), or gas (air). The most common type is thromboembolism, where a clot travels to occlude another vessel. Other etiologies include fat, air, septic, cholesterol (atherosclerotic) embolisms, tumor embolism, and amniotic fluid embolism.

Emboli lodge in small vessels, causing tissue ischemia or infarction. Clinical effects depend on the affected territory: pulmonary embolism presents with chest pain and dyspnea; cerebral embolism with sudden neurological deficits; coronary embolism with chest pain or myocardial infarction; peripheral embolism with limb pain and ischemia.

Diagnosis combines history, examination, and imaging. Pulmonary embolism is evaluated with CT pulmonary angiography or ventilation–perfusion scanning; cerebral embolism with CT or MRI; Doppler ultrasound detects associated deep vein thrombosis; echocardiography may identify cardiac sources.

Treatment aims to restore perfusion and prevent recurrence. Anticoagulation (typically heparin followed by a direct oral anticoagulant or warfarin) is common for thromboembolism. Thrombolysis or surgical/percutaneous embolectomy may be used in severe cases. Supportive care includes oxygen and treatment of the underlying cause.

Prevention focuses on reducing embolus formation: risk-factor modification, early mobilization after surgery, pharmacologic prophylaxis in high-risk patients, and, when anticoagulation is not possible, selective use of vena cava filters.