Duplicated Cervical Internal Carotid Artery with Ipsilateral Persistent Stapedial Artery and Contralateral Aberrant Internal Carotid Artery: A Case Report.

Objective: Duplication of extracranial cerebral arteries is a rare anatomical variant, most commonly observed in the vertebral artery. However, duplication of the cervical internal carotid artery (ICA) is extremely rare. We present a unique case of a patient diagnosed with a right facial artery aneurysm, in whom a right duplicated ICA, ipsilateral persistent stapedial artery (PSA), and contralateral aberrant ICA were incidentally identified. Case Presentation: A 56-year-old woman presented with a painless mass in the right lower jaw. Physical examination revealed a round, pulsatile mass. Contrast-enhanced CT demonstrated a 25 mm saccular aneurysm originating from the right facial artery, along with a right duplicated ICA and a left aberrant ICA. The lateral limb of the right duplicated ICA and the left aberrant ICA were seen traversing the tympanic cavity and entering the carotid canal. The absence of the right foramen spinosum indicated the presence of a PSA. Angiography confirmed the duplicated ICA, aberrant ICA, and PSA. The lateral limb of the right duplicated ICA gave rise to the occipital artery and a small branch, the PSA, which entered the middle cranial fossa. The facial artery aneurysm was successfully embolized. Follow-up MR angiography showed stable occlusion of the aneurysm, with the duplicated ICA giving off both the PSA from the lateral limb and a pharyngeal branch from the medial limb. Conclusion: This case provides valuable insights into the development of the cervical arterial system during the fetal period, particularly the collateral pathways connecting the third arch to the dorsal aorta.