The aortic diverticulum: a remnant of the partially involuted dorsal aortic root.

The aortic diverticulum, a large bulge on the lesser curvature of the aortic isthums, is an occasional variation found during thoracic aortography in patients with a left aortic arch and normal origin of the brachiocephalic arteries. Although it is commonly thought to be a remnant of the closed ductus arteriosus, the results of this study support the hypothesis that it is a remnant of the right dorsal aortic root.