Calcified obstructive disease of the aortic isthmus.

A 52-year-old man presented with a calcified thrombus measuring 5 cm in length, which was responsible for obstruction of two-thirds of the aortic isthmus lumen. At operation the thrombus was seen to stem from an ulcerated plaque in the aortic wall, 4 mm in diameter. Six years later, his aortograms were normal. We believe the thrombus had an atheromatous origin.