Bilateral infraoptic origin of the anterior cerebral artery: illustrative case

BACKGROUND: A bilateral infraoptic origin of the anterior cerebral arteries (ACAs) is a rare anatomical variant that can be encountered during anterior skull base surgery. The ACAs arise from the internal carotid artery (ICA) at the level of the ophthalmic artery and course medially, traveling inferior to the ipsilateral optic nerves. Herein, the authors discuss the different configurations of the anatomical variant, its prevalence, and hypotheses leading to the variable configuration of this anomaly. OBSERVATIONS: A 67-year-old woman presented with worsening dizziness over a week-long period and was found to have a large left sphenocavernous meningioma with optic, cavernous, and suprasellar extension. The tumor incorporated the left supraclinoid ICA and its branches. She underwent a left modified orbitozygomatic craniotomy for tumor resection. Early identification of the aberrant ACA anatomy was crucial in avoiding vascular injury. LESSONS: While this variant is typically encountered during the treatment of vascular pathologies—namely, intracranial aneurysms—its existence should be kept in mind during the treatment of any anterior skull base pathology. Failure to account for the presence of this variant may lead to potential intraoperative complications.