Ectopic origin of the ascending pharyngeal artery: implications for carotid surgery.

In its normal anatomy, the extracranial internal carotid artery (ICA) does not have branches. The most common cause of an extracranial ICA branch is the ectopic placement of one of the named external carotid artery branches. Other causes of extracranial ICA branches include persistent fetal carotid-vertebrobasilar anastomoses and recannalized intersegmental arteries. In this case, report we describe a 55-year-old male who was found to have an ascending pharyngeal artery (APA) arising from the ICA during neck dissection. The aberrant APA was not identified on pre-operative imaging. The patient underwent a successful carotid endarterectomy (CEA) with preservation of flow through the ascending pharyngeal. We review the literature on the origin of the APA and discuss the clinical implications of extracranial ICA branches.