Aberrant innervation of the lateral abdominal muscles by direct branch of L4 nerve

Surgical approache through the posterior abdominal wall used for nephrectomy or other access to contents of the retroperitoneal space requires to be cognizant of the regional nerve supply to the posterolateral abdominal wall muscles. We herein report a, to our knowledge, previously undescribed direct branch from the L4 spinal nerve that formed a plexus with regional nerves to then innervate the lateral abdominal wall musculature. Such a nerve variant should be considered by the surgeon who operates this region