Transverse muscular lumbar vein

The third lumbar vein presents a marked transverse tributary draining the abdominal wall. This venous tributary, called the transverse muscular lumbar vein (Lumbar vein of Michmich), emerges from the abdominal parietal wall on the proximal attachment of oblique muscles, 1 cm above the iliac crest, and runs anteriorly to the surface of the quadratus lumborum muscle (as opposed toother muscular branches of lumbar veins that are located posterior to this muscle). The vein of Michmich ends the lumbar vein in the angle formed by psoas muscle and the quadratus lumborum.