Introduction: Anterior cerebral artery variations are often observed and have clinical implications if pathology involves the ACAs or surrounding structures and a variant is present. Bilaterally crossed anterior cerebral arteries are a previously undocumented finding in this vascular territory. A patient is presented with incidentally identified bilaterally crossed anterior cerebral artery circulation during digital subtraction angiography for tumor management.

Methods: A patient with known metastatic prostate cancer and a recently diagnosed large right extra-axial occipital mass underwent cerebral angiography for potential tumor embolization prior to resection.

Results: Diagnostic cerebral angiography demonstrated bilaterally crossed anterior cerebral arteries as the typical anterior cerebral artery distribution in each hemisphere received cross-filling from the contralateral circulation. Although incidental, this is likely an asymptomatic variant in a vascular region with frequent pathologies and anatomic variants.

Conclusions: A previously undocumented variant of bilaterally crossed anterior cerebral arteries is described. While likely uncommon, this variant is an addition to several well-documented anterior cerebral artery anatomical variants. Ongoing appreciation of these variants is critical due to the frequent pathology and procedures involving the anterior cerebral vasculature.

Patient Care: Anterior cerebral artery anatomy and variants are necessary knowledge for many neurosurgical procedures. Documenting new findings in this region may offer immense benefit due to the frequent pathology and surgical procedures in this region.

Learning Objectives: 1) Describe the normal anterior cerebral artery anatomy. 2) Describe common variants encountered in the anterior cerebral artery and anterior communicating artery vasculature. 3) Demonstrate knowledge of bilaterally crossed anterior cerebral arteries and the potential clinical implications.

References: 1. Jinkins, JR. Atlas of neuroradiologic embryology, anatomy, and variants. 1st ed. Baltimore: MD. Lippincott Williams and Wilkins; 2000. 2. Perlmutter D, Rhoton AL. Microsurgical anatomy of the distal anterior cerebral artery. J Neurosurg. 1978 Aug; 49(2): 204-28