THOROTRAST-ASSOCIATED OROPHARYNGEAL HEMORRHAGE - TREATMENT BY MEANS OF CAROTID OCCLUSION WITH USE OF FLOW ARREST AND FIBERED COILS

THOROTRAST, a colloidal suspension of thorium dioxide, was widely used in both Europe and North America as an intravascular contrast agent f rom 1929 until the mid 1950s (1,2). Thorium dioxide's production of al pha radiation with a physical half-life of 1.4 x 10(10) years combined with its propensity to be permanently deposited in reticuloendothelia l tissues made it unsuitable for clinical application. As early as 193 2, the Council on Pharmacy and Chemistry of the American Medical Assoc iation advised against its use (3-5). Despite this, it is estimated th at more than 50,000 people worldwide (4,300 in the United States) were exposed to this material (6). Adverse effects of thorotrast are gener ally manifest some 20-30 years after exposure and most commonly consis t of the development of liver cancers as well as leukemia (7). Thorotr ast can also induce an intense chronic granulomatous foreign body resp onse at sites of extravasation (8). These thorotrast granulomas, or '' thorotrastomas,'' most commonly occur in the neck and are due to the e xtravasation of the contrast agent occurring at the time of carotid ar teriography performed with direct carotid puncture. The subsequent int ense fibrotic response sometimes may extend throughout the neck and ca n result in neuropathies of the lower cranial nerves (IX through XII), as well as a variety of other nonspecific compressive symptoms such a s dyspnea and dysphagia (3,4). Vascular occlusion and rupture have als o been reported (2,6,9-11). We describe a case of severe oropharyngeal hemorrhage due to a thorotrast-related carotid artery pseudoaneurysm managed by means of endovascular occlusion of the carotid artery with use of fibered coils in conjunction with temporary flow arrest.