Protruding atheromas in the thoracic aorta: a newly recognized source of cerebral and systemic embolization

Abstract

Up to 40% of stroke patients do not have an obvious etiology for their illness. Because transthoracic echocardiography is often negative in these patients, there has been increasing enthusiasm for transesophageal echocardiography (TEE) as a newer tool for evaluating patients with embolic disease. In a study of patients referred because of unexplained stroke or transient ischemic attacks, the most common finding was protruding atheroma in the aortic arch. In a case control study, protruding aortic atheromas were found in 33 of the 122 patients with emboli (27%). Mobile components to the atheromas were found in 11 case patients, and there were no mobile components found in any control patients. It is also possible that protruding aortic atheromas may play a role in patients with other sources of emboli (e.g., carotid disease). Atheromas may also cause emboli during catheterization, balloon pump placement, and cardiopulmonary bypass. The pathological composition of the lesions seen on TEE has been atheroma with superimposed thrombus. The correct treatment for patients with embolization due to protruding aortic atheromas has not yet been determined, although anticoagulation may play a role, since the mobile components to these lesions appear to be thrombus. We have recommended surgery for several patients. However, the operation is a major one with major potential complications, including aortic dissection. TEE should be done in patients with unexplained emboli, and it may also play a role in patients with other sources of embolization. TEE should be considered in elderly patients or those with extensive vascular disease before cardiac catheterization or heart surgery. In addition, cannulation techniques during bypass can be modified to avoid atheromas. The ideal medical and/or surgical approaches to patients with protruding atheromas remain to be clarified.