What is embolism? |

Causes and Symptoms

An embolism is a mass of undissolved matter traveling in the vascular or lymphatic system. Although an embolism can be solid, liquid, or gaseous, the majority of emboli are solid. Likewise, emboli may consist of air bubbles, bits of tissue, globules of fat, tumor
cells, or many other materials. The majority of emboli, however, are blood clots (thrombi) that originate in one portion of the body, break loose and travel, and eventually lodge in another part of the body. Where the traveling blood clot lodges will determine what kind of damage is done.

If the thrombus starts in the veins of the legs, it may break loose, travel up the veins of the leg and abdomen, pass through the right side of the heart, and lodge in the arteries in the lungs. This condition, called a pulmonary embolism, is often fatal. If the embolism is small, it may cause only shortness of breath and chest pain. If it is even smaller, the embolism may produce no symptoms at all.

If a blood clot forms in the chambers of the heart, breaks loose, and eventually lodges in an artery in the brain, then the patient will experience a stroke. If a clot breaks loose and lodges in an artery in the leg, then the patient will experience pain, coldness, or numbness in that leg. A blood clot that lodges in the coronary arteries, the arteries that feed the heart muscle, may cause a heart attack.

Treatment and Therapy

Treatment will vary depending on what system has been affected by the embolus. If the clot lodges in the lungs, then the patient will likely be placed on a blood-thinning drug such as heparin. In severe cases, thrombolytic drugs, which dissolve clots, may be used. If the clot lodges in a coronary artery, then open-heart surgery may be performed to bypass the occluded artery. If the clot lodges in the leg, a surgeon may remove the clot from the artery. This procedure is possible only when the clot is discovered early, when it has not yet formed a strong attachment to the vessel wall. Another approach to this problem may be to bypass the occluded artery using an artificial artery or a graft.

Perspective and Prospects

The prevention and treatment of emboli are constantly improving. Venous thrombosis, the most common cause of pulmonary emboli, is becoming easier to diagnose thanks to major advances in ultrasound imaging. Also, magnetic resonance imaging (MRI) is being used to make the identification of emboli in the lungs more accurate and safer. Procedures for imaging the chambers of the heart, a common spot where emboli form, are improving as well, making prevention easier.

Bibliography

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Bick, Roger L. Disorders of Thrombosis and Hemostasis: Clinical and Laboratory Practice. 3d ed. Philadelphia: Lippincott Williams & Wilkins, 2002.

Kroll, Michael H. Manual of Coagulation Disorders. Malden, Mass.: Blackwell Science, 2001.

MedlinePlus. "Pulmonary Embolism." MedlinePlus, May 16, 2013.

National Center on Birth Defects and Developmental Disabilities, Division of Blood Disorders. "Deep Vein Thrombosis (DVT)/Pulmonary Embolism (PE)—Blood Clot Forming in a Vein." Centers for Disease Control and Prevention, September 25, 2012.

Verstrate, Marc, Valentin Fuster, and Eric Topol, eds. Cardiovascular Thrombosis: Thrombocardiology and Thromboneurology. 2d ed. Philadelphia: Lippincott-Raven, 1998.

Virchow, Rudolf L. K. Thrombosis and Emboli. Translated by Axel C. Matzdorff and William R. Bell. Canton, Mass.: Science History, 1998.