A Rare Congenital Anastomosis between the Vertebral Artery and Internal Carotid Artery

Lateral view of right common carotid arteriogram. There is contrast material filling of the right external carotid artery and its branches. The right internal carotid and its branches cannot be demonstrated.

Fig 2. Lateral view of right vertebral arteriogram. There is contrast material filling of right internal carotid artery (A, arrow). It arises from the cervical portion of right vertebral artery at the level of C2, with mild grade stenosis at its origin. The right middle cerebral artery is supplied by the vertebrobasilar circulation through the posterior communicating artery (B).

Fig 3. Frontal (A) and lateral (B) views of the right internal carotid artery in the right vertebral arteriogram. This artery is shown more clearly during the late arterial phase of the right vertebral arteriogram. The intracranial supply cannot be demonstrated probably due to its slow flow. The right ophthalmic artery is also not well seen due to the same reason.

Fig 4. Frontal view of the left internal carotid arteriogram. The A2 segment of right anterior cerebral artery is supplied by A1 segment of left anterior cerebral artery through the anterior communicating artery.