Thorium-dioxide--induced pharyngeal hemorrhage.

Thorium dioxide, a producer of alpha particle radiation, was used in the United States from 1930 to 1950 for carotid and cerebral angiography. Cervical thorium dioxide granuloma is a well-recognized sequela of extravasation of this material near the carotid bifurcation. Radical neck dissection to remove the granuloma for aesthetic and functional reasons may lead to massive postoperative hemorrhage if a patent, but radiation-weakened, carotid artery is present. Additionally, hemorrhage may occur spontaneously because of pharyngeal necrosis or following infection of a pharyngeal biopsy site. The case described illustrates that life-threatening, thorium-dioxide--induced pharyngeal hemorrhage may occur even with an occluded carotid system. The bleeding site may go unrecognized, and laryngopharyngectomy with radical neck debridement may be required for hemostasis. Extension of an infection into the retroesophageal space and thoracic inlet requires exteriorization of the entire neck wound to prevent placing the great vessels of the superior mediastinum at risk for rupture. Spontaneous rupture of the aorta may occur due to thorium-dioxide--induced necrosis of its wall.