| CAS candidates | CEA candidates | |
| Anatomical factors | Lesion above C2 | lipid-rich soft plaque |
| Below collarbone injury | further injury to 15 mm | |
| Reoperation after previous CEA | preocclusive injury | |
| Cervical stoma | severe circumferential Calcification | |
| Previous cervical radiotherapy | aorto-iliac tortuosity | |
| Previous ablative cervical surgery | Great angulation of the aortic arch and carotid artery | |
| heavily calcified aortic arch or with severe atherosclerosis | ||
| Pathophysiological factors | Heart disease | Patient over 80 years |
| Contralateral vocal cord paralysis |