MOBILE THROMBOSES OF THE AORTIC-ARCH WITHOUT AORTIC DEBRIS - A TRANSESOPHAGEAL ECHOCARDIOGRAPHIC FINDING ASSOCIATED WITH UNEXPLAINED ARTERIAL EMBOLISM

Background Atherosclerotic lesions of the aortic arch are potential so urces of arterial embolism. Mobile thrombi in the aortic arch in young patients without diffuse atherosclerosis have been reported recently, but such cases remain exceptional. Wa describe a series of young pati ents with unexplained arterial embolism in whom transesophageal echoca rdiography detected mobile aortic arch thromboses. Methods and Results Transesophageal echocardiography files collected between 1991 and 199 5 in French academic cardiology centers were reviewed to identify pati ents who fulfilled the following criteria: (1) an arterial embolic eve nt in the preceding weeks; (2) a mobile pedunculated aortic arch throm bosis, defined as an echogenic mass protruding into the lumen of the a orta and inserted on the aortic arch; and (3) absence of obvious diffu se aortic atherosclerosis or of aortic debris on transesophageal echoc ardiography. Twenty-three cases were identified from 27 855 examinatio ns. Thromboses were located on the horizontal aorta (n=4), near the os tium of the left subclavian artery (n=5), or on the concavity of the p osterior segment of the aortic arch (in the isthmus) (n=14). The inser tion site was a small atherosclerotic plaque in 21 patients. The remai ning aortic wall always appeared normal or mildly atherosclerotic. The mean age of the patients was 45 +/- 8.4 years (range, 26 to 61 years) . All patients were treated with intravenous heparin after the diagnos is of aortic arch thrombosis, and surgical removal of the thrombosis w as performed in 10 patients in whom histological examination confirmed an atherosclerotic process at the site of insertion of the thrombosis . The prognosis was mainly influenced by embolic events. Conclusions T hromboses of the aortic arch appear to be a variant form of aortic ath erosclerotic disease associated with arterial embolism in young patien ts.