Bilateral asymptomatic extracranial carotid artery aneurysms.

Aneurysms of the extracranial carotid arteries are rare and account for 0.4-1% of all arterial aneurysms and about 4% of all peripheral arterial aneurysms. Causes include atherosclerosis, fibromuscular dysplasia, trauma (penetrating and blunt cervical trauma and hyperextension of the neck), iatrogenic lesions, infection, congenital defects, and irradiation arteritis. Atherosclerosis is responsible for 46-70% of all carotid artery aneurysms. The most frequent site of carotid artery aneurysms is the common carotid artery, particularly at its bifurcation and proximal internal carotid artery (ICA). The middle and distal portions of the ICA are the next most common sites. Aneurysms at the point of bifurcation are usually fusiform, whereas those located in the middle and distal portions of the ICA are usually saccular. This uncommon but interesting vascular disorder usually presents as a parapharyngeal pulsatile mass. It can be partially or completely thrombosed and thereby cause embolization or compression of neurovascular structures, with ruptures and ischemic events as other complications. Surgical treatment of extracranial carotid aneurysms is required in most cases, to avert disastrous consequences. Conservative management of extracranial ICA aneurysms has resulted in a mortality rate of nearly 71%. Nonoperative treatment is generally indicated in young patients who have nonpenetrating traumatic and spontaneously dissecting aneurysms. However, when anticoagulation therapy fails or when persistent neurologic symptoms or progressive expansion of the aneurysm occurs, surgical repair is indicated.