Aneurysms of the petrous internal carotid artery: anatomy, origins, and treatment.

Aneurysms arising in the petrous segment of the internal carotid artery (ICA) are rare. Although the causes of petrous ICA aneurysms remain unclear, traumatic, infectious, and congenital origins have been implicated in their development. These lesions can be detected incidentally on routine neuroimaging. Patients can also present with a wide spectrum of signs and symptoms, including cranial nerve palsies, Horner syndrome, pulsatile tinnitus, epistaxis, and otorrhagia. The treatment of petrous ICA aneurysms remains challenging. Treatment options include close observation, endovascular therapies, and surgical trapping with or without revascularization. Management dilemmas exist, particularly for incidental lesions found in asymptomatic patients. The authors review the literature and discuss the anatomy of the petrous ICA as well as the pathophysiological features of aneurysms arising in this region, and they propose a management paradigm with current treatment options.