The accessory anterior cerebral artery: case report and anatomic analysis of vascular anomaly.

BACKGROUND

The term "accessory artery" was formulated to describe one of the developmental anomalies of the middle cerebral artery. This anomaly consisted of the incidence of a vessel that branched off close to the anterior communicating artery and supplied a part of the cortex in the region of the middle cerebral artery vascularization.

METHODS

A panangiography of the cerebral vessels was carried out, using the subtraction method, on a woman who suffered from subarachnoid hemorrhage. An aneurysm of the anterior communicating artery and developmental anomaly of the right anterior cerebral artery were found. During the aneurysm operation, the existence of the developmental anomaly was confirmed. It was revealed also during a control angiography.

RESULTS

An atypical branch of the right internal carotid artery was found branching off from section C2, and passing below the right optic nerve and the anterior communicating artery. This branch ended with a division into the orbitofrontal and frontopolar artery.

CONCLUSIONS

The atypical branch of the internal carotid artery that partly performs the function of the existing proper right anterior cerebral artery, has been defined as the accessory anterior cerebral artery.