Saccular aneurysm of the proximal left common carotid artery.

Aneurysms of any part of the extracranial carotid artery are uncommon lesions [1-6], and those involving just the common carotid segment may appropriately be considered rare. Although fusiform enlargement of the mediastinal segment of the left common carotid artery can occur in atherosclerotic disease and in association with syphilitic and other forms of aortitis, a saccular form of aneurysm in this location has been recorded only in a few instances after blunt chest trauma [79], and all have been designated as pseudoaneurysms. We report an apparently unique case of saccular aneurysm of the left common carotid artery root in a patient without history of trauma or sepsis.