Carotid Mycotic Aneurysm associated with Persistent Primitive Hypoglossal Artery. Case Report and Literature Review.

Carotid mycotic aneurysm is extremely rare and even more unusual when it is associated with a persistent primitive hypoglossal artery. This artery is the second most common of the embryonic carotid-vertebrobasilar anastomoses. It originates from the cervical internal carotid artery and enters the cranium through a widened hypoglossal canal before anastomosing with the basilar artery. We report a case of an elderly man with a rare Salmonella-induced mycotic aneurysm associated with a persistent primitive hypoglossal artery. Surgical resection of the mycotic aneurysm was complicated by a posterior circulation stroke. To the best of our knowledge, there was no previous report of a carotid mycotic aneurysm associated with a persistent primitive hypoglossal artery thus far in the literature. Owing to the high mortality rate of the carotid mycotic aneurysm, it is imperative to be familiar with the vascular and imaging anatomy prior to surgery particularly in the presence of an embryonic carotid-vertebrobasilar anastomosis. In this report, we highlight the imaging characteristics and treatment options for this rare mycotic aneurysm together with a literature review.