RESUMO
BACKGROUND AND IMPORTANCE: The median sacral artery (MSA) is a relatively small vessel that always arises from the posterior, terminal part of the infrarenal aorta. In most cases, the MSA runs behind the iliocaval junction. Here, we describe a very rare case of an MSA running in front of this junction. CASE REPORT: During a human cadaveric dissection of the retroperitoneal area, we unexpectedly observed that the MSA passed in front of the left common iliac vein. CONCLUSION: The anatomy of the MSA has been extensively described and variations are quite rare. On the basis of this specific case, knowledge of the anatomic interactions between the MSA and other lumbar retroperitoneal vessels may help to avoid potential complications during surgery.