Unilateral anomalous lateral branch of the abdominal aorta piercing the left renal vein - A case report.

A sound knowledge of variations in the branching pattern of the abdominal aorta is crucial for operative, diagnostic, and endovascular procedures. We report a unilateral anomalous lateral branch of the abdominal aorta observed during dissection classes.This anomalous branch took origin from the anterior surface of the abdominal aorta behind the left renal vein and pierced the left renal vein. After piercing the left renal vein, it traced a tortuous course through the peri-renal fat pad in front of the lower part of the left kidney. The artery then ran downward and laterally, pierced the anterior layer of thoracolumbar fascia, and continued to the posterior abdominal wall to supply its muscles. It also supplied the fat and fasciae around the kidney. Such an anomalous lateral branch could bleed significantly during renal surgery. It could also mislead radiologists during the invasive radiologic procedures.