ATHEROMATOUS DISEASE OF THE THORACIC AORTA - PATHOLOGICAL AND CLINICAL IMPLICATIONS

Purpose: To review recent developments in the diagnosis, clinical epid emiology, pathology, and management of atherosclerosis of the thoracic aorta, especially atherosclerosis of the thoracic aorta as a source o f embolization. Data Sources: MEDLINE searches, bibliographies of publ ished papers, and consultation with experts in the field. Study Select ion: English-language publications on atherosclerosis of the thoracic aorta were selected. Data Synthesis: During the last 6 years, the incr easing use of transesophageal echocardiography has shown that atherosc lerotic plaque in the thoracic aorta is a source of otherwise unexplai ned embolic events, including stroke, transient ischemic attack, and p eripheral emboli. Retrospective studies have documented a strong indep endent association between larger lesions (4 mm to 5 mm) and previous embolic disease, and prospective studies have shown that patients with these lesions have a high risk for future events (in one study, the r isk for stroke was 12%; in another, the risk for cerebral or periphera l events was 33% in a follow-up period of just 14 months). These lesio ns also pose a serious risk for embolization caused by manipulation of the aorta during catheterization, intra-aortic balloon-pump placement , and cannulation of the aorta for heart surgery. Pathologic examinati on has shown atherosclerotic plaque, often with superimposed thrombi t hat account for the mobile components seen on transesophageal echocard iography. The management of patients who have atherosclerotic lesions in the thoracic aorta has not been determined prospectively. However, anticoagulation may help prevent emboli, as it does for patients who h ave thrombi in other locations, such as the left atrium and the left v entricle. Conclusions: Protruding atherosclerotic lesions in the thora cic aorta, often with superimposed mobile thrombi, are an important ca use of embolic disease. Transesophageal echocardiography should be con sidered in the work-up of patients who have unexplained embolic events .