A Ruptured Anterior Communicating Artery Aneurysm with Infra-optic Course of the Anterior Cerebral Artery: A Case Report and a Short Review

Infra-optic course of the anterior cerebral artery (IOA) is rare and approximately 55 cases of this anomaly have been described. We present a case of a ruptured anterior communicating artery (ACoA) aneurysm arising at the junction between the left IOA and the bilateral A2 segments, at which the right A1 segment was absent. One of the recurrent arteries of Heubner branched off directly from the aneurysmal dome, and was obstructed at aneurysmal neck clipping via an anterior interhemispheric (AIH) approach. In this report, accompanied anatomical variations and surgical approaches for ACoA aneurysms with IOA are reviewed. An IOA is frequently associated with other vascular anomalies, and the origin of functionally important recurrent arteries of Heubner is also variable. Preoperative accurate evaluation of vessel structures and the maximal exposure at surgery are very important. Pterional approach from the ipsilesional side is reportedly to be safe, but interhemispheric approach is also suggested to be effective as to full exposure to recognize the perianeurysmal anatomical structures including potential vessel anomalies.

Anatomy of the Ophthalmic Artery: Embryological Consideration

There are considerable variations in the anatomy of the human ophthalmic artery (OphA), such as anomalous origins of the OphA and anastomoses between the OphA and the adjacent arteries. These anatomical variations seem to attribute to complex embryology of the OphA. In human embryos and fetuses, primitive dorsal and ventral ophthalmic arteries (PDOphA and PVOphA) form the ocular branches, and the supraorbital division of the stapedial artery forms the orbital branches of the OphA, and then numerous anastomoses between the internal carotid artery (ICA) and the external carotid artery (ECA) systems emerge in connection with the OphA. These developmental processes can produce anatomical variations of the OphA, and we should notice these variations for neurosurgical and neurointerventional procedures.

Infraoptic course of anterior cerebral arteries associated with abnormal gyral segmentation

✓ The authors report the case of a 34-year-old woman who presented with increasing headaches. Neuroimaging revealed bilateral anomalous vessels arising at the level of each ophthalmic artery, coursing rostromedially to join the anterior communicating artery (ACA), which harbored an aneurysm. Intraoperatively, the authors identified an abnormal gyral segmentation of the frontoorbital region, with a median gyrus separated from the olfactory tracts on each side by the gyrus rectus. No interhemispheric fissure was observed in the exposed area. This is the first report in the literature of an abnormal gyral segmentation in association with an infraoptic course of an ACA. Recognition of this possible gyral abnormality in association with this vascular anomaly is relevant for surgical exposure and treatment of aneurysms by clip placement.

Treatment of an anterior communicating artery aneurysm through an anomalous anastomosis from the cavernous internal carotid artery

Cavernous internal carotid artery (ICA)-anterior cerebral artery (ACA) anastomoses are unusual anomalies in which a duplicated A, segment of the ACA arises from the infraoptic ICA. The authors report on a 30-year-old woman who presented with subarachnoid hemorrhage from an anterior communicating artery (ACoA) aneurysm associated with an extremely rare variant of this anastomosis. The extra A, segment emerged from the ICA within the cavernous sinus rather than at or above the level of the ophthalmic artery. The presence of the anomalous vessel provided a straightforward endovascular approach to the ACoA and allowed the use of coil placement rather than surgical clipping to treat the aneurysm successfully.