RESUMEN
INTRODUCTION: This case report illustrates a new variant in the anterior cerebral artery complex, identified during carotid angioplasty. CLINICAL CASE: A 50-year-old male patient diagnosed with left carotid stenosis was diagnosed and treated by a cerebral angiography. During the procedure, crossed circulation in the anterior cerebral artery was identified. The presence of this variation demanded to discard distal emboli or artery dissection. Angioplasty was performed and the patient followed up without neurological deficit. DISCUSSION: Among the most possible and prevalent variations in anterior circulation, none of them explain the phenomenon we observed. Therefore, a new variant is established. The knowledge about variants in cerebral circulation is important to rule out pathology. CONCLUSION: Cerebral diagnostic angiography has become more available and frequent because of the rising in endovascular tools to treat stroke patients. Considering this new variation and others is important to discard pathology.