[Anatomic variations of the internal carotid artery: implications for the neurologic endovascular therapist].

Tortuosity of the cervical segment of the internal carotid artery (ICA) can hinder navigation intravascular devices for treating intracranial aneurysms and even complex ICA access techniques can fail. Variations in the course of the internal carotid artery are known as coiling, kinking or tortuosity of the vessel. Such failures have clinical relevance.