Anatomic study of the lateral femoral cutaneous nerve with respect to the ilioinguinal surgical dissection

Objective: To report on the anatomic variations of the lateral femoral cutaneous nerve with respect to the ilioinguinal surgical dissection. Design: Cadaveric anatomic study. Patients/Participants: Sixty-eight ilioinguinal dissections performed in fifty cadavers. Intervention: The lateral femoral cutaneous nerve was identified, and certain location variables were recorded. Main Outcome Measure: The distance in millimeters from the medial edge of the anterior superior iliac spine (ASIS), whether the nerve was lateral or medial to the ASIS, and the layer in which the nerve crossed the dissection. Results: In seven dissections, the nerve was twenty-one to twenty-five millimeters medial to the ASIS; in ten dissections, the nerve was twenty-six to thirty millimeters from the ASIS; and in fourteen dissections, the nerve was more than thirty millimeters medial to the superior border of the ASIS. The average medial distance from the ASIS was 20.4 millimeters, with a range of three to forty-six millimeters. In no specimen did the nerve pass lateral to the ASIS. The lateral femoral cutaneous nerve was found to lie anterior to the iliopsoas muscle in all specimens. Conclusion: The course of the lateral femoral cutaneous nerve is highly variable; the nerve was most commonly found at ten to fifteen millimeters from the ASIS and as far medially as forty-six millimeters. When using the illioinguinal surgical approach, if the lateral femoral cutaneous nerve is not encountered immediately adjacent to the ASIS, dissection up to five centimeters medial to the ASIS may be necessary to locate the nerve.