Problems in the identification of the lateral femoral cutaneous nerve: variant of long trajectory. Surgical implications

Introduction: The lateral femoral cutaneous nerve may be injured during the laparoscopic inguinal hernia approach or inadvertently sectioned during triple neurectomy as a treatment for post-surgical chronic pain. The objective of this work is to present a variant and conduct a literature review. Material and method: Dissection of 10% adult cadavers, in the Anatomy Chair of the Faculty of Medicine of the Catholic University of Murcia. The trajectory of the lateral femoral cutaneous nerve, and of the entire lumbar plexus, was analyzed based on its local relationships, both at the retroperitoneal and anterior inguinal levels. Results: In most cases, the lateral femoral cutaneous nerve is unique, crossing the retroperitoneal space from the lateral border of the psoas to the anterior superior iliac spine and passing to the thigh in a medial area of the inguinal ligament. Variations described are: early bifurcation, epiphasic position, origin of the femoral branch of the genitofemoral, of the ilioinguinal or its absence. We describe a long path variant on the quadratus lumbar muscle of difficult clinical differentiation of the ilioinguinal. Conclusions: 1. Retroperitoneal surgery cannot identify with certainty the different nerves of the lumbar plexus. 2. A nerve should never be sectioned without cranial verification and caudally adjacent ones. 3. Femoral cutaneous nerve may present variants that make its recognition difficult, especially with respect to the Ii, and should be taken into account in any laparoscopic surgery to avoid undesirable morbidity.